Defender No Sound

studiopaul

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Philadelphia, Pennsylvania
Currently working on my defender, all works fine except has no sound.

have checked voltages at sound board.
Sound

= +12vdc
= -5vdc
= -13.8 vdc. (too high?)

Pushing and holding button on sound card produces no sound.
this also has a toggle switch..i have tried moving this in both positions with no effect.

AMplifier has hum when turned up loud.. static on pot..assume speaker and amp are good

I have also reflowed all pcb
andbuzzed out ribbon from rom board to sound board = all tested ok

Switched out 6808p ..same problem.
and cleaned rom1 from rom board


Rom board bellow has the 2 far leds on 2 closest off.

Where should i begin my testing?

So far I have read to replace C13 and C14 although the board layout looks a little different

not a technical test ..but placing fingers near sound rom..hearing faint garbled defender sounds???
 
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Board seems larger, is this the original defender circuit?
As schematics show D8224 sound board, which looks more compact, different values of capacitor.

By Touching top side of Sound Rom and center of board..I get a loud repeated clear defender start sound..repeating..pushing the switch it re triggers the same sound but starts it at the beginning of sound..
If tried to short the pins to trigger sounds but it remains dead.

Any takers on this one?
 

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Resocket the ROM. If you can touch it and get some life out of it then it sounds like, at a minimum, you have and intermittent connection somewhere.
 
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