(From: Martin Sniedze (MSniedze@STRNNTS1.telecom.com.au)). I found that the keypad was always getting wet/oily somehow. Cleaning with alcohol only fixed the dialing problem for about a week. A bit of asking at phone repairer revealed that sanyo has a 'possible' problem with the keypads absorbing/emitting the oily substance. The repairer sold me a membrane that goes between the silicon keypad and the PCB, it has carbon pads on the back. It stops the moisture getting through. It has completely fixed the problem in my phone (it was done 6 months ago). They should be free.
The following applies to normal desk or wall phones, cordless phones, modems, answering machines, fax machines - essentially anything plugged or wired into the phone system. Always check the cords first - especially the one between the handset and the desk or wall phone itself since it gets a lot of abuse. Noisy, intermittent, or totally dead behavior is possible. In some cases, even the (electronics) ringer will not work if a wire in this cord is broken as the ringing signal is generated in the handset and sent back to the ringer unit. Try jiggling the cord at both ends to see if noise is generated or behavior changes. Even permanently wired in cords are replaceable - just take care to draw a diagram and/or label all the wires before disconnecting the old one. Bad connections are relatively rare in original ATT dial or Touch Tone telephones. These old phones also used very high quality contacts for the on-hook, dial, and button switches which rarely resulted in problems. However, with the multitude of modern equipment of all degrees of quality, bad connections and dirty or degraded switches and relays are very common. The various microswitches and/or relays for on-hook and other functions seem to be particularly prone to degredation if not properly specified in the design. If phone line pickup or mode switching is noisy or erratic, this is a likely cause. Most of these swiches and relays are replaceable although creativity may be required as an exact match may not be easy to locate. To assure that the problem is actually with the particular piece of equipment, disconnect other devices on the same telephone line. Aside from the obvious oversight of a phone that has not been hung up, modems or fax machines that are not powered on may load the phone lines excessively. For example, if you have two PCs with modem connections to the same phone line, the signal quality on one of them may degrade to the point of reducing the effective transmission speed, producing an excessive error rate, or not successfully connecting at all if the other is turned off. (They may also behave strangely if the Originate/Answer settings of the modem are set incorrectly - but that is another matter.)
Most signal problems will be related to failed components on the telephone line side of the coupling transformer including components in the phone line derived power supply (if used). Phone lines are subject to all kinds of abuse including lightning strikes (although something significant may do extensive damage beyond reasonably hope of repair). * Test all the components on the telephone line side of the coupling transformer when line connect, detect, or dial problems are encountered. There may be shorted semiconductors due to a voltage spike or just bad luck. * Some units extract power from the phone line and the rectifiers or other related components can go bad. This can result in either power problems (telephone is totally dead) or dialing problems. * Make sure you are using the proper AC adapter and test it for correct output. * There could be a defective power supply inside the phone - the regulator could be shorted or a filter capacitor could be dried up. See the chapter: "Equipment Power Supplies". * Check for loose or broken connections - phones get dropped. * For erratic dialing problems, inspect and clean the keypad and other switch contacts. Also see the section: "Cordless phone problems".
First, confirm that your modem settings are correct - reset the modem to factory defaults using the Hayes AT commands (e.g., AT&F1
) or dip switch settings. Confirm that your software is set up correctly and that there are no IRQ or IO address conflicts. If the modem starts to dial but aborts and hangs up, confirm that you do not have the wiring of the 'telco' and 'phone' connectors interchanges. Also see the section: "Erratic or noisy telephone equipment". Since the phone line is subject to all kinds of abuse, most actual problems (that are not software related), will be on the phone line side of the coupling transformer. * There will be various diodes, transistors, capacitors, opto-isolators, and relays for routing the incoming and outgoing signals, or for protection and these can fail shorted or open. * There may be an actual fuse (or more than one) as well - but it will probably not look like a common fuse but may be very tiny - more like a resistor - or even a surface mount part. Hopefully, the circuit board will be marked 'F1' or 'PR1' or something similar. Check fuses for opens. * A lightning strike is likely to obliterate components in the modem beyond even your abilities to salvage it. If it arcs over the coupling transformer or just induces a large enough voltage spike, the logic circuitry will be history. However, in many cases, damage is minor. If you have signal problems - a modem will try to dial out but not make its way to the phone line, testing on each side of the couping transformer with a scope or Hi-Z headphones should be able to determine if the problem is on the logic or phone line side of the device. Check that the proper AC adapter is being used (if relevant) and that is is putting out the proper voltage. Check the internal power supply components for proper output. They are often common IC regulators like the 7805 and are easily tested. Replacements are inexpensive and plentiful. (From: Rick Miller (email@example.com)). First thing to check: almost all modems have a pair of low-value resistors (10-20 ohm) between the phone line and their line transformer. I got a 2400 baud voicemail modem for free this way! Repaired an "unrepairable" modem (according to the ACER computer technician! :) ) Replaced a "booger resister" with a real 1/2 job.... had to work hard to get the leads soldered onto the SMT pads!:) (From: Jordan Hazen (firstname.lastname@example.org)). Yes, in my experience you're much more likely to sustain damage from a phone-line surge than anything on the power grid. Modem electronics tend to be more delicate than the stuff in your power supply. First thing to check: almost all modems have a pair of low-value resistors (10-20 ohm) between the phone line and their line transformer. These are intended to take the brunt of a lightning hit and protect the electronics upstream. Traditionally, these have been large, high-current resistors (like 1/2 watt), but sometimes now they try to get away with little 1/16-watt surface mount ones that are much more likely to blow. Sometimes it's obvious when the resistors have died, with visible singe marks, pieces blown away(!), etc. Usually these fail as an open, resulting in "NO DIALTONE" on trying to connect. Other vulnerable stuff includes the zener diodes intended to clip down incoming ring voltage, on the transformer "primary" (telco) side. These may fail as a short-circuit. The ring-detect optoisolator may also blow, and it can simply be removed if you don't need to take incoming calls. One of my modems actually had the line relay's contacts welded together by a lightning hit, so it stayed off-hook constantly! Check the isolation transformer for a open coil on either side. If it's a high-speed modem, be sure to replace blown transformers with one of about the same type & quality... the ones on 2400-baud modems usually had poor frequency response/linearity. Any damage beyond the transformer will be hard to repair w/o a schematic, since the surface-mount diodes, transistors, etc. damaged may be hard to ID for replacement on a surface-mount board. Something blown in this area may cause slow/error-prone connections, rather than complete failure. It happened to be with a particularly nasty strike (the one welding the line relay closed), transforming a 33.6k modem into a 4800 :-( Oh, and if the modem's completely dead - no response to AT commands-- you're probably out of luck... this means there's damage to the digital logic, and it's invariably the 200-pin custom ASICs that blow rather that 74xxx buffers. (From: email@example.com). My experiences with the front end of answering machines are welded relay contacts mostly. The symptom is usually holding down the line.
See the document: "Surface Mount (SMD) Transistor/Diode Cross-reference". If this does not list your device or it is so fried that no markings survive, you can usually use some educated guesswork to select a suitable replacement. SMD types can usually be replaced with normal devices since there is usually sufficient space. If there are any other SMD parts with the identical marking, you should be able to determine pinout (e.g., BCE for transistors - see the document: "Testing of Semiconductor Devices with a DMM or VOM") and replace with a general purpose non-SMD type. I doubt that the specifications of parts used in telephones or modems are critical. Even if there are no identical device, if you can determine the voltages on the pins, you may be able to guess the type. The worst that will likely happen if you are wrong is to blow your replacement device - anything that this will do the rest of the circuitry has already been done.
Small hand held and desk calculators share many of the same afflictions as hand held IR remote controls. In particular, battery and keypad problems are common. Caution: many devices using LCD displays utilize a printed flex cable to interconnect the electronics and the display. Often, this is simply glued to the LCD panel and possibly to the logic board as well. The cables are quite fragile and easily torn. They are also easily ripped from the adhesive on the LCD panel or logic board. If the unit is fairly old, this adhesive may be very weak and brittle. Repair or replacement should this occur is virtually impossible. The material used for the conductors is a type of conductive paint that cannot be soldered. It may be possible to use a similar material like the conductive Epoxy used to repair printed circuit boards but this would be extremely tedious painstaking work. Be extremely careful when moving any of the internal components - LCD, logic board, keyboard, battery holder/pack, and printer. The following problems are likely: 1. Batteries - one or more cells are dead, weak, or have leaked. Try a new set if normal primary cells (e.g., alkaline) are used. Clean the battery contacts. Where rechargeable (usually NiCd) batteries are used, one or more cells may have shorted resulting in a dead calculator or dim display, or printer that doesn't work reliably. See the chapter: "Batteries". Test each cell after charging for the recommended time or overnight. NiCd cells should be about 1.2 V when fully charged. If any are 0 V, the cell is shorted. This is particularly likely with a unit that has been left in a closet unused for an extended period of time. It is generally recommended that the entire battery pack be replaced rather than a single cell as the others are probably on their way out and the capacities will not be equalized anyhow. Rechargeable batteries may be the cause of a calculator that does not work properly on AC power as well since they are usually used like a large filter capacitor and shorted cells will prevent the required DC voltage from being provided to the electronics. Open cells or bad battery connections will prevent this filtering as well and may result in erratic operation or other symptoms. For this reason, it may not be possible to run a unit of this type reliably or at all with the rechargeable batteries removed. Some calculators that use rechargeable batteries like older HPs and TIs have a battery pack of 24.4 to 3.6 V with a DC-DC inverter to obtain the 9 V or so that the NMOS chipset required. These rarely fail except possibly due to leakage of neglected dead batteries. However, good batteries need to be in place for the calculator to work properly. If you are not interested in using these types of calculators on batteries, disconnect the DC=DC convertor and substitute a suitable AC adapter. Check the voltage and current requirements for your particular model. 2. Keypad - dirt, gunk, and wear may result in one or more keys that are intermittent or bounce (result in multiple entries). Disassemble, clean and restore the conductive coating if necessary. See the document: "Notes on the Troubleshooting and Repair of Hand Held Remote Controls". 3. Printer (where applicable) - in addition to replacing the ribbon when the print quality deteriorates, cleaning and lubrication may be needed periodically. Dust, dirt, and paper particles collect and gum up the works. Clean and then relube with light machine oil or grease as appropriate. Sometimes, gears or other parts break resulting in erratic operation or paper or other jams. Locating service parts is virtually impossible. 4. AC adapter - if the calculator does not work when plugged into the AC line, this may be defective - broken wires at either end of the cord are very common. However, shorted cells in an internal NiCd battery will likely prevent the proper voltage from being supplied to the electronics even when using AC power since the battery is often used like a large filter capacitor at the same time it is being charged. Open cells or bad connections to the battery pack may result in erratic operation or other symptoms as well. Don't overlook the obvious: are you using the proper adapter and if it is a universal type, is the polarity and voltage set correctly? Check the specifications. With the proliferation of AC adapters, it is all to easy to accidentally substitute one from another device.
There may be a thermal fuse under the outer layers of insulation with is the only casualty. It is worth checking out. (The specific example below is for a Sharp desktop calculator, model CS-1608. It has a power transformer with 6 wires on the secondary: 2 red, 2 yellow, 1 orange, and 1 brown.) Power surges, overheating, or connecting a 115 V device to a 220 V line can all blow the primary. An overload could also but is likely not the problem. In my experience, it seems that the transformers in these things are designed so close to core saturation that excess voltage will not be transferred to the secondary and even plugging a 115 transformer device like a digital clock into a 220 line will not kill the logic, but just melts the transformer primary. I have a bag full of the things (including a cordless phone) which were damaged in this manner when someone decided to do a little house rewiring. You can guess the rest. As far as the calculator goes, there are probably 2 sets of secondary windings probably with centertaps - check it with a multimeter. I would guess that the brown is the centertap for the reds and the orange is the centertap for the yellows but simple tests will confirm or refute this. One may be for the logic and the other for the printer motors, LCD, who knows? Obviously, if you can obtain an exact replacement, **this** is truly the best solution. Short of this, try to find someone who can measure the secondary voltages on a working model of this calculator. Then, you could replace the transformer with a pair of readily available transformers with suitable ratings. If you feel on the lucky side and can at least determine which wires go with which windings, you could carefully bring up power on one output and see if there is any response. It will be at least 5 V. Examining the regulation circuitry and filter capacitors could also provide a clue. Also, you could determine the ratio of the secondaries by powering one from a low voltage AC source and measuring the output of the other (assuming the primary isn't so messed up as to load down the transformer due to shorts). There are many options besides giving up.
Many will have a couple of screws (possibly hidden under rubber feet or inside the battery compartment) or snaps which will permit the two halves of the case to be separated. However, some very popular models are apparently not designed to be repaired at all: Note: I have heard that there is a somewhat less destructive (but not any easier) procedure for getting inside HP48s than that given below but have not seen it. (From: A.R. Duell (firstname.lastname@example.org)). Have you ever tried to open up an HP48 (or just about any HP calculator later than the 71B)? It's non-trivial to do non-destructively - these darn things are held together by pegs that were melted over after the case was assembled. From memory (and I've never actually done a 48, just the smaller ones) you have to: 1. Remove batteries, cards, etc. 2. Carefully peel off the metal overlay on the keyboard. This can be done without putting a fold in it, but it takes practice. 3. Use a 4 mm (I think) drill held in the fingers to remove the tops of the moulded studs holding the case together 4. Pull off the back part of the case. You can now see the circuit board. It's held down by twisted metal tabs. The keyboard is under it, and is held together by a lot more of those infernal moulded studs.
First, try a fresh battery and clean the battery contacts if necessary. If the battery is very low or dead, well.... When the battery is low or the connections are bad, the countdown logic may run erratically - fast as well as slow. Give it a week and then see if the problem still exists. If it does - and the error is only a few minutes a week - then an adjustment may be all that is needed. If the error is much worse - like it is running at half speed - then there is a problem in the logic - time for new clock (or at least a new movement). There should be a recessed screw for fine speed adjustment accessible from the back - possibly after a sticker or outer cover is removed. It may be marked with a couple of arrows and if you are lucky, with the proper direction for speed increase and decrease. Without test equipment, the best you can do is a trial and error approach. Turn the screw just the tiniest bit in the appropriate direction. If this is not marked, use counterclockwise to slow it down and vice-versa. Wait a week, then readjust if necessary. If you have frequency counter with a time period mode, you can try putting it across the solenoid terminals and adjusting for exactly 1.000000 second. Hopefully the load of the counter will not affect the oscillator frequency. With sensitive equipment, it may even be possible to do this without any connections by detecting the fundamental frequency radiation of the quartz crystal oscillator and adjusting it for exactly 32,768 Hz (most common). However, keep in mind that the clock's quartz crystal accuracy required to gain or lose less than 1 minute a month is about +/- 1 part in 43,000 which may be better than that of your frequency counter's timebase. One alternative is to perform the same measurement on a clock that is known to be accurate and then match the one you are adjusting to that.
Common problems include totally dead, missing segments in display, running at the wrong rate, switches or buttons do not work. (Also applies to the clock portions of clock radios.) Note that these is often a battery - possibly just an 9V alkaline type for backup in the event of a power failure. If this is missing or dead, any momentary power interruption will reset the clock. Although a totally dead clock could be caused by a logic failure, the most likely problem is in the power supply. The power transformer may have an open winding or there may a bad connection elsewhere. A diode may be defective or a capacitor may be dried up. Often, the secondary of the power transformer is center tapped - test both sides with a multimeter on its AC scale. Typical values are 6-15 VRMS. If both sides are dead, then the primary is likely open. There may be a blown fusable resistor under the coil wrappings but a burnt out primary is likely. Although generic replacement transformers are available you will have two problems: determining the exact voltage and current requirements (though these are not usually critical) and obtaining a suitable regulatory (UL. CE, etc) approved transformer - required for fire safety reasons. If the transformer checks out, trace the circuit to locate the DC outputs. These power supplies are usually pretty simple and it should be easy to locate any problems. Missing segments in the display are most likely caused by bad connections. Try prodding and twisting the circuit board and inspect for cold solder joints. A clock that runs slow on 50 Hz power or fast on 60 Hz power may not be compatible with the local line frequency since these clocks usually use the power line for timing rather than a quartz crystal. This is actually a more precise (as well as less expensive) approach as the power line frequency long term accuracy is nearly perfect. Sometimes there is a switch or jumper to select the line frequency. Dirty switches and buttons can be cleaned using a spray contact cleaner.
Computer clocks use a crystal and are not tied to the AC line - after all, they have to keep time even when the computer is unplugged. Cheap digital clocks that plug into the AC line are extremely accurate - better than anything else you are likely to have access to short of the broadcast time signal. The reason for this is that the power line frequency is referenced to an atomic clock somewhere and its long term accuracy is therefore maintained to great precision. Even the short term frequency stability is very good, changing by at most a small fraction of 1 percent due to variations in electric load affecting generator speed (U.S national power grid - isolated areas with local power generators could see much much wider swings). These clocks may not keep good time if (1) the power line is very noisy, (2) there is a power outage, or (3) they are broken. Power line noise on the same circuit might confuse some clocks, however. This might happen with light dimmers or universal motors (e.g., vacuum cleaners, electric drills, etc.) on the same circuit.
About the only type of service you can expect to perform is battery replacement but even this can save a few dollars compared to taking the watch to a jeweler. The typical watch battery will last anywhere from a year (alkaline) to 5 years (lithium). The most likely cause of a watch that has a dead or weak display, or has stopped or is not keeping proper time is a weak or dead battery. The batteries (actually single cells) used in most modern watches (they used to be called electric watches, remember the Accutron?) are either alkaline or lithium button cells. Some are quite tiny. You will need to open up the watch to identify the type so that a replacement can be obtained. How you go about doing this will depend on the watch: 1. Screws. If there are visible screws on either the front or rear, then removing these will probably enable the cover to be popped off. These will be teeny tiny star (sort of Philips) head type - use a precision jeweler's screwdriver with a Philips head tip. Immediately put the screws into a pill bottle or film canister - they seem to evaporate on their own. 2. Snap off back. This is probably most common. Look for an indentation around the edge. Using a penknife or other similar relatively sharp edged tool in this indentation or at any convenient spot if there is none. It is best to use the wristband mounting rod as a lever fulcrum if possible. The back should pop off. Note the orientation of the back before you set it aside so that you can get it back the same way. 3. Cover unscrews. The entire back may be mounted in a screw thread around its edge in which case you will have to somehow grab the entire back and rotate counter clockwise. An adjustable wrench with some tape to protect the finish on the watch may work. If there is an O-ring seal (like on the space shuttle), be careful not to nick or otherwise damage it (you know what happens when these are damaged!). Once the back is off, you will see a lot of precision stuff - though not nearly as much as in an old fashioned mechanical watch. DON'T TOUCH! You are interested in only one thing - the battery. Sometimes, once the back is off, the button cell will simply drop out as there is no other fastener. In other cases, one or two more teeny tiny screws will hold it in places. Carefully remove these and the button cell. Replace the screws so you will not loose them. Make a note of the orientation of the button cell - it is almost always smooth side out but perhaps not in every case. Test the battery with a multimeter. The voltage of a fresh battery will be about 1.5 V for an alkaline cell and as high as 3 V for a lithium cell. A watch will typically still work with a battery that has gone down to as little as half its rated voltage. Replacement batteries can be obtained from Radio Shack, some supermarkets, large drug outlets, electronic distributors, or mail order parts suppliers. Most likely, you will need to cross reference the teeny tiny markings on the old battery - places that sell batteries usually have a replacement guide. Cost should be about $2.00 for a typical alkaline cell and slightly more for the longer lived lithium variety. Note: some watches bury the battery inside the works requiring further disassembly. This is usually straightforward but will require additional steps and some added risk of totally screwing it up. Install and secure the replacement battery and immediately confirm that the display is alive or the second hand is moving. If it is not, double check polarity. Sometimes, the back will need to be in place for proper contact to be made.
First check the batteries (if any). Self powered meters like the old Westons and their clones could also cause damage to the delicate meter movement if the light regulating lid was left open in bright light. Bad connections were also common. I have repaired the meter movements on these but it is not much fun. Hand held light meters are subject to damage from being dropped. Problems with internal light meters include bad batteries and corroded battery contacts, dirty or worn potentiometers.
It seems that in the last few years, the amount of circuitry crammed into a compact 35 mm camera has grown exponentially. Auto-film-advance, auto- exposure, auto-film speed detection and loading, auto focus, auto-flash selection, auto-red-eye reduction - just about everything that could be put under computer control has been. Next thing you know, the photographer will be replaced with a auto-robot! For the most part, modern cameras are very reliable. However, when something goes wrong, it is virtually impossible to attempt repair for two reasons: 1. The circuitry is so crammed into a tiny case that access is difficult and convoluted. Many connections are made with relatively fragile flexible printed cables and getting at certain parts means removing a whole bunch of other stuff. 2. Much of the circuitry is surface mount and many custom parts are used. Schematics are nearly impossible to obtain and with all the computer control, probably not that useful in any case. Most parts are not available except from the manufacturer and then possibly only to authorized service centers. However, some problems can be addressed without resorting to the camera repair shop or dumpster. If the camera is still under warranty, don't even think about attempting any kind of repair unless it is just a bad battery. Almost certainly, evidence of your efforts will be all too visible - mangled miniature screw heads and damaged plastic seams - at the very least. There are no easy repair solutions. Let the professionals deal with it. If out of warranty and/or you don't care about it and/or you want an excuse to buy a new camera, then you may be able to fix certain (very limited) types of problems.
For anything beyond the battery, you will need to get inside. However, before you expend a lot of effort on a hopeless cause consider that unless you see something obvious - a broken connection, bent or dirty switch contact, or a motor or other mechanical part that is stuck, binding, or in need of cleaning and lubrication - there is not a lot you will likely be able to do. One exception is with respect to the electronic flash which is usually relatively self contained and simple enough to be successfully repaired without a schematic. As with other consumer electronics equipment, getting inside may be a challenge worthy of Sherlock Holmes. In addition to many obvious very tiny screws around the periphery, there may be hidden screws inside the battery compartment and under the hand grip (carefully peel it back if that area is the last holdout). Also see the section: "Getting inside consumer electronic equipment". This is the time to make careful notes and put all the tiny parts in storage containers as soon as they are removed. If you never follow any of these recommendations for other types of equipment, at least do so for pocket cameras! Caution: the energy storage capacitor for the electronic flash may be located in an unexpected spot way on the other side of the camera. Accidentally touching its terminals when charged will be unpleasant to say the least. Even if the camera is 'off', some designs maintain this capacitor at full charge. In addition, it may retain a painful charge for days - with the battery removed. Once you get the skins off of the camera (if you ever succeed), identify this capacitor - it will be about the size of a AA battery - and put electrical tape over its terminals.
The following malfunctions may sometimes be successfully dealt with without an army of camera repair technicians at your disposal: Caution: never open the back of a 35 mm camera anywhere there is light of any kind if there is a chance that there is film inside. If the camera is dead, there may be no way of knowing. Doing this even for an instant may ruin all of the film that has been exposed and two (usually) additional pictures. Opening the back of any other kind of roll film camera will only expose a few frames as the exposed film usually has a backing (120) or is inside a cartridge (110). If a 35 mm camera failed with a roll of film on which you have taken irreplaceable photographs inside, the pictures can still be saved even if the camera never works again. First, wash your hands thoroughly to remove skin oils. Use a closet with a tightly fitting door (at night is better or stuff something in any cracks to block all light - it must be pitch black) for a darkroom. Open the back of the camera and carefully remove the film cassette. Gently pull the exposed film from the takeup spool (on the shutter release side of the camera). It should unwind easily. Avoid touching the film surface itself with your fingers (the edges are ok). Then, turn the plastic shaft sticking out of the film cassette clockwise to wind the exposed film entirely into the cassette. (For items (2)-(4), you will need to get inside of the camera. See the section below: "Getting inside a pocket camera".) 1. General erratic or sluggish operation, weak display, camera pooped out during film advance or rewind. Most likely cause: the battery died. Test the battery and/or try a new one. It is possible that the battery simply decided to go flat at an inconvenient time or that a replacement was defective. If possible, check the voltage on the battery while it is in the camera and the affected operations are performed. If the voltage drops substantially, there could be an overload - a motor that is binding or a shorted component. If the camera had been dropped, a mechanical problem is likely. 2. Flash inoperative or excess current drain - runs down batteries. Other functions may or may not work correctly. Most likely cause: a shorted inverter transistor. The electronic flash or strobe is usually a self contained module near the actual flash window but the energy storage capacitor may be mounted elsewhere - like the opposite side of the case. See the warning below - you could be in for a surprise! 3. Mechanical problems with focus, exposure, film advance, or rewind. Likely causes: binding due to damage from being bumped or dropped, bad or erratic motor operation, gummed up lubrication or dirt, or defective driver or control logic. Locate the motor for each function (right, good luck) and confirm that they spin freely and move the appropriate gears, levers, cogs, wheels, or whatever. If there is any significant resistance to movement, attempt to determine if it is simply a lubrication problem or if something is stuck. Test the motors - see the section: "Small motors in consumer electronic equipment". 4. Auto-film-loading, film advance, or rewind do not operate at all or do not terminate. Most likely cause: defective motor or mechanical problems, dirty, corroded, or faulty sensor switches or bad controller. If there is no action or something seems to get stuck or sounds like it is struggling, check the battery and motor (see (1) and (3) above). Inspect the various microswitches for broken actuators, bent or deformed contacts, or something stuck in them like a bit of film that broke away from the roll. Dirt may be preventing a key contact closure. Sometimes, improper cable routing during manufacture can interfere with the free movement of a leaf type contact. 5. Exposure too light or too dark. Check the film speed setting and/or clean the contact fingers under the cassette that sense the film (ASA or ISO) speed. Clean the light meter sensor. Check the batteries, Look for evidence of problems with the lens iris and/or shutter mechanism. If the shutter speed can be set manually, see the section: "Testing of camera shutter speed". 6. Automatic camera not responding to adjustments. Changing the diaphragm or shutter speed usually moves a variable resistor which is part of the exposure computer. If a single control has an erratic effect or no effect, its variable resistor is likely dirty or broken. If none of the controls behave as expected, there may be a problem in the actual circuitry that computes the exposure. There is little chance that you could repair such a fault. First, replace the batteries. Some of these systems will behave strangely if the batteries are weak. Unless there is something obvious - the diaphragm control is not engaging the lever of the variable resistor, for example, and you care about the future health of your camera, my recommendation would be to take it in for professional service. To successfully repair modern sophisticated compact cameras requires that you be really really experienced working on teeny tiny mechanisms, have the proper precision tools (e.g., good quality jeweler's screwdrivers, not just the $2 K-Mart assortment), bright light and a good magnifier, and a great deal of patience and attention to detail.Go to [Next] segment
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