A4000 output sound problems, and what is causing it...

I had a problem on the output sound on my A4000...so i decided to look on the Mainboard and discovered that Batterys aren´t the only things that leaks acid on the boards...Capacitors can do the same damadge...look the capacitors ( C433 22uF 16v ) there are two, between Paula and the RCA jackets...for my Amiga was too late i hope my experience can save others Amigas...well...my A4000 is not dead...it works, but...no Sound...

[xeron]

Its a VERY common fault for paula audio to die on the A4000. I've lost the left channel on mine, and I know of 3 other A4000 owners (4 now i've read yours) where it has died.  :-(

   Exactly, the left channel was the first one to "die" but those capacitors, expecially the left capacitor, if not removed, the "disease will spread to the nearby components"

[blobrana]

hehe,
I had a problem like that ( with a battery on a accelerator board ). i removed it and the machine wouldn`t boot!

I had to solder it back on, i only had a butter knife ( which i heated on the cooker ) , and i managed to scrape some solder off a old pc board....

It worked!
 
try one of these stores....


http://amigaworld.net/modules/mylinks/viewcat.php?cid=3
 :-D

( C433 22uF 16v ) there are two, between Paula and the RCA jackets...for my Amiga was too late

Have you tried replacing said capacitors? If the electrolyte has leaked out, instead of a capacitor between the jacks and the chip you have a dead short. I'm not saying this will fix it (paula may be fubar) , but it is probably worth a try. :-)

   Yes, i´ve removed those capacitors, and tryed to replace them, but, didn´t work. all y can guet it´s a poor quality sound...but, i will keep trying.

[SilvrDrgn]

I just got a problem like this fixed on my A4000D motherboard over the weekend.  The capacitors on my board have been replaced by the non-polarized type.  However, upon putting everything back together, the sound on my A4000 was still terrible.  After 7.5 hours of messing around with the hardware (different motherboard, accelerator, removing expansion cards, removing Zorro expansion daughter board), my dealer and I found the problem.  It was as simple as the -12 volt and it associated ground wire not making proper contact in the main 6-pin motherboard power connector.  When I plugged that in after the capacitor change, the -12 volt and its ground got pushed out of the connector somehow so they weren't making contact.  The op-amps (operational amplifiers) that produce sound on the Amiga require -12 and its ground in order to function properly.  Without either one, the sound output is very bad.  We connected the main power connector and then wiggled and pushed in the wires with a pair of needle-nosed pliers.  After that, perfect sound from my system!