Problem with sound in my A4000T

[other_reality]

I have this problem lately with the sound in my Amiga. It seems that it mostly occurs when in Workbench though and not when booting from a floppy. I tried both the RCA and the stereo jack outputs, and sound comes out distorted when in game (either cd based or whdload) and when i try to listen to a mod via hippoplayer. Sometimes it just crackles by itself

I tried to install AHI again - i really dont know if this could be the cause though - and the installation will not complete, an error occurs when reaching the DOSdriver folder, and i tried it from several amiga format cdroms.

[Loedown]

Capacitors in the audio stage are gone or part(s) of the LF347 tracks have been eaten away by bad capacitors.

[FOL]

Originally Posted by Loedown

Capacitors in the audio stage are gone or part(s) of the LF347 tracks have been eaten away by bad capacitors.

Yep, had the same thing Audio daughter board on A4000T here.
Had to remove caps to see damage, as it wasnt visable.

[Loedown]

Originally Posted by FOL

Yep, had the same thing Audio daughter board on A4000T here.
Had to remove caps to see damage, as it wasnt visable.

I didn't realize the audio board is separate in an A4000T, I've only repaired standard A4000 MB so far.

[other_reality]

Originally Posted by FOL

Yep, had the same thing Audio daughter board on A4000T here.
Had to remove caps to see damage, as it wasnt visable.

So how did you repair it ? Is it only a matter of replacing the capacitors or does it go any deeper? I'm new to repairing circuit boards, i usually just replace them !

edit: Νevermind, will hand it to a friend who repairs boards and hopefully he'll know what to do ! Thanks

[FOL]

Originally Posted by other_reality

So how did you repair it ? Is it only a matter of replacing the capacitors or does it go any deeper? I'm new to repairing circuit boards, i usually just replace them !

edit: Νevermind, will hand it to a friend who repairs boards and hopefully he'll know what to do ! Thanks

I had to repair the track, as the cap leakage had physically eaten through the tracks.

[orange]

@other_reality

I had the same problem. thoroughly clean the area and replace the caps. iirc, they are 22uF:
http://www.amiga.org/gallery/index.php?n=1430

[FOL]

Originally Posted by orange

@other_reality

I had the same problem. thoroughly clean the area and replace the caps. iirc, they are 22uF:
http://www.amiga.org/gallery/index.php?n=1430

Yep, CE320A was the one that leaked here.
Killed the track under it.

To be honest, I avoided it for ages, as A4000T has a stereo jack socket.
That worked fine, then stopped, so I was forced to find issue, .

[other_reality]

I passed all the info and images/schematics to my father, and gave him the board. He's an old time tv repairman and has much more experience with soldering than me (wouldnt sit down and learn how to solder when I was young, i just wanted to play sensi and make protracker mods ). Thanks a lot guys, you've been really helpful, and hopefully i will get back a working board with crystal clear sound !

[other_reality]

After replacing the capacitors and cleaning the track, the sound is back crisp and clean, and no more crackling sounds - cheers !

I also have A4000T with same audio trouble. I have just ordered a new one A/V module from SoftHut (USA) taking advantage from currency conversion, it takes less than EUR 40.00, shipping included.

[orange]

@puppy
capacitors cost less than dollar.. and its not that hard to replace them.
so perhaps someone would be willing to buy your old AV module.