I have an Addams that was working fine (the sound board was one that i grabbed from a project machine that has not been powered up for probably 8 years - but worked fine for a number of weeks), then the sound became quite distorted - like it was playing underwater and very scratchy.

I have -

reseated ROMs, socketed IC's and ribbon cables heaps of times

replaced caps C15,36,38,20,23,46,47

Speakers are fine at 4ohm and pull in with a 9V battery

I'm wondering where the next place on the sound board is to look at replacing/fault finding - there seems to be very little repair information on these boards....

Thanks

Rob

Yeah, i've also swapped boards and the problem follows - so its definitely a board issue

Changing C24 and C25 makde no difference. I replaced a heap of other capacitors without any luck. In the end, i replaced 5 more capacitors - i am unsure which one (or ones) made the difference as i changed them all before testing again. The ones i changed were:

C34 and C37 (one was a 47uF, the other 1uF - i don't recall which was which)

C26,C27,C28,C29 (all 1uF)

Many of these were tantalum capacitors, but i replaced them with more readily available electrolytics. Anyway, the sound is back to completely normal now. If i come across this issue again, i will try and narrow it down to the exact capacitor!

So does this mean i might have problems down the track? I just can't source the tantalums from my local supplier. Or are the differences that small that it may not be noticeable?