I'm working on fixing a casio wk1630 organ.

[toon5150]

I've been trying to fix a casio wk1630 for a friend. I haven't been able to find any circuit diagram manuals or pin outs for voltage readings. The keyboard comes on but no sound. When you press keys the display shows the key that was pressed but no sound. Also when you turn on the drums to play there is no sound. I have inspected every inch of the circuit boards and wiring checking for broken traces or cold solder joints and found nothing. I have metered all the wiring and it is all good. I did find some evidence of something getting spilled on it so I'm assuming one of the IC chips is bad. Just need a repair manual for it.

 

[happyrat1]

If something was spilled onto the motherboard it's possible none of the chips are bad, but rather some residue underneath one of the chips is shorting a few pins.

Try pulling the board, washing the affected area liberally with denatured alcohol and then drying it thoroughly with a hairdryer and then let it air dry out for a few more days..

The fact is that the logic component sounds OK since it is still lighting up the display and registering the keypresses so I'd focus my attention on the DAC chip and OP AMPs if you can identify them.

Gary

 

[toon5150]

Ok, when I said it looks like there was evidence of something spilled, I meant it had already dried. I already cleaned with Contact cleaner.

 

[happyrat1]

Nonetheless, while there is almost no airflow underneath a chip, the gap is not watertight. There could be some gum under the chip that's hard to clean.

Anyway, check your chip numbers.

Like I said earlier, the logic sounds OK so I'd concentrate on the DAC, the OP Amps and possibly the ROMs.

If a chip fried, you'd probably have no display at all.

What kind of V++ readings are you getting between ground and the supply pins on the chips?

If those are looking normal, then try tracing a signal thru the audio chain.

Do you have a scope available?

If not, you can pick up a cheap handheld scope these days for under $100 from Amazon Chinese Resellers.

Robot Check

Gary