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Sega game gear recap. Answered

I have been repairing Sega game gears for a week now and i seem to be having a consistent problem with the VA1 single ASIC boards. i recap them and none of the work. Ive recapped tons of the twin ASIC boards with no problem i was wondering if anyone could help me figure out why i cant seem to get them working. the power comes on so the power board is good. no sound but the backlight CFL comes on. any help will be greatly appreciated. I am a Blacksmith by trade and happy to trade smithing knowlage for electrical

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Downunder35m
Downunder35m

27 days ago

Please post one or two highres images of both sides of the offending circuit board.
If possible mark or note the capacitors you replaced.

I have to assume your problem is directly in the power supply area.
What things do you have at hand to trave voltages on the board?

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jeffparker1
jeffparker1

27 days ago

I'm Face Same issue please help me

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Orngrimm
Orngrimm

4 weeks ago

I never owned a game gear nor have i ever checked a PCB of them...

For the following, a schematic will be of great help.

That said, i am gladly giving general advice on bughunting:
- Be sure all the passive components (R, C, D) are "clean" and dont show signs of corrosion. If they do, replace them.
- Be sure that all the Connectors are still operable. Often, PCB-Slots become oxidised. Also, bigger connectors can have a mechanical failure in the PCB-Trace just where they are soldered due to mechanical stress and movement. A microscope should help you there.
- Be sure you have all necessary clock-signals present. Be aware that normally you cannot measure a cristal directly due to the much too low impedance of a DSO or Multimeter. Measure the field or with a VERY high isolated active probe.
A LMC6061opamp may help you there if you set it in voltagefollower-mode and use it as impedance-converter. https://imgur.com/a/qaa77jZ for reference
- Be sure the individual chips still work:
o Check for corroded legs
o check for shorted legs
o if possible, check if they do anything or are a dead piece of silicon