help my amiga 4000 has little or no sound output

[Darmaster70]

My amiga 4000 desktop boots up just fine. I do not get the dark gray light grey boot up screens, my screen stays dark blue. The computer seems to work just fine no problems with programs locking up, screen looks ok but when I try to play some mod files using octamed my sound is crackly and very low in volume. Does anyone have any ideas.
Thanks

I had this problem with my a1200 after i intalled the Z4 add-on card. It turned out that one of the screws shorted out and burned out the -5V rail on the motherboard. Try measuring the -5V on the PSU. Not sure what the pinout of the a4000 is though.

[Lo]

If your pooter has rca jacks for audio,  you might
check the soldering of the jacks with a magnifier.

A more dangerous way is to wiggle them while
trying to play sounds.

[blobrana]

I s it just with octamed?

[Darmaster70]

Octimed is the only program i have tried. It used to work fine but now it doesn't (octimed that is). I understand the blue screen means i might have a problem with the custom chips but not sure.

[Lo]

 8-) =error found in ROMS
 :-D =error found in Chip Ram
 :-( =error found in custom chips
 :-? =if the CPU found an error b4
the guru was running.

 :-D  :pint:

[Lo]

Blue is cool, I never had a blue screen.
All my amiga's died with the green screen
of DEATH which usually turned out to be bad
chip memory.  (Sometimes reseating agnus
cures).
Anyways, custom chips should be cheep.

[SilvrDrgn]

@ Darmaster70,

octamed my sound is crackly and very low in volume

By chance, have you had or still have an internal CD-ROM audio cable connected to the internal audio connector on the motherboard??  If you acquired the computer second hand, it's possible that the previous owner had the connection made.  I found that when I connected mine to my CD-ROM drive, the native Amiga audio did exactly what you're describing.  Unfortunately, when I removed the cable, the problem still happens.  Apparently, there is a fix for it, but it involves soldering of some sort on the motherboard.  I have not been able to find the details for it.

Could someone please let me know where to find such audio fix documentation

[Darmaster70]

I do not have an internal CD-ROM audio cable connected to the internal audio connector on the motherboard

[SilvrDrgn]

Did you acquire the machine used???  If so, a previous owner could have had it connected and caused the problem.  Still looking for the motherboard fix .... anyone

[Darmaster70]

Yes I bought it used but it had an external cd-rom. I installed a scsi internal cd drive but i didn't attach anything to the motherboard. I used to get the dark grey light grey screens during boot up but now all i get is a dark blue screen through the boot up process. When i first got the machine it worked fine. I replaced the barrel shaped battery but it was not leaking anything on the mobo. I may have messed something up when i removed the battery but other than having no sound the computer seems to work fine.

It is caused by a fried track on the PCB, near to the audio mixer connector.  It's happend to two of my A4000s in the past.  Fast Compuers in Tanner Street, London SE1 know exactly how to fix the fault.

And if you don't live in the UK?  My A4000 developed the same problem a while back.

[SilvrDrgn]

O.K.  Back to this problem again - especially when it is caused by connecting the internal audio cable from a CD-ROM drive to the A4000 motherboard internal audio mixer connection.  I have since disconnected the cable, but my A4000 still has little to no output and it always produces static/noise through the speakers regardless if anything is actually trying to play.

So, where can I find documentation on how to fix this problem??  Or who/where, in the U.S., can fix this for me???

[Darmaster70]

One question for you silver dragon, when your computer boots do you get the dark grey light grey white boot colors?