No power!
Always no disc!
No video!
No audio!
No LCD display! (optional)
Sunday
Television
Power problem? No power, Check first the fuse, just trace the power cord to the main board and you'll find the fuse. If busted, try checking the power regulator if shorted. The power regulator is screwed on a heat sink and located near the big filter capacitor. Test the regulator on the board using a multi-meter check the collector to base and collector to emitter. If shorted, dis-solder the regulator and remove it then test the board where the regulator is soldered if shorted. If none, it means the parts to be replaced is the fuse and the power regulator.
Video problem? Dark display, blurry display, white display with trace lines and no display.
Audio problem? No sound,
Wednesday
Cell Phone
Power problem? Check your battery and your power switch, if still good try searching the net about the unit and if available a schematic diagram would be found. If not, trace it manually. There are spots were positive supplies are connected, the back lights positive side, the RX TX positive pin and a lot more. Also, if you happen to have a unit with same model you can compare its positive ways to the other and take note about it. ^_^
Charging Problem? Check first if your battery is working, check your charger if it works on other cell phone or try measuring the output supply if you have a DC voltmeter. If your battery and charger are working, next is troubleshooting the inner part of your mobile phone. Try tracing the charging line or your charger jack connection. Look for the fusable component marked with three zeros or the letter K and a capacitor connected from this fusable component. Test the fuse with a continuity tester if it's open and the capacitor if leaky or shorted. Replace the damage components with same kind of parts or an ordinary fuse and capacitor with the same size (can also be found on a CD-Rom drive board). Assemble your phone then try charging. If nothing happens, replacing your charging IC might solve the problem. ^_^
Signal problem? Make sure that your sim card is not blocked or your phone is open lined. If true, troubleshoot the inner part. Try tracing the positive input of the RXTX IC by measuring its continuity with the phone positive battery connector. If ti has no continuity, you can put a wire jumper (shielded or insolated wire) between them. If this doesn't work, try the antenna switch by placing jumpers between pin 6, 12 & 16. If nothing happens, replacing the IC might solve this problem. ^_^
Audio Problem? Buzzer (ring tone speaker), check first your phone buzzer if working by using a continuity tester (buzzer often broke cause of over used), if the buzzer is ok check the buzzers contact points continuity to the control IC. Locate the buzzers output from the control IC then place a wire jumper between them. Mic (mouth piece), trace and check the mic's connection by following the mic's contact point at the phones main board. Check all the possible components that the mic's connection runs trough like resistor, transistor or diode. Speaker (ear piece), again check your phone speaker if working by using a continuity tester, if true trace the line connection trough the components near the CPU of your cell phone. If you have the knowledge, you can put a wire jumper. ^_^
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