A4k no audio!

abraXXious

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Erm, Im presently a little p^ssed off...

I sent an a4k MB away to have an audio problem fixed. The audio was crackly and distorted. From the research I did, I found that it could either be failing caps or a failing psu.

So I got an ATX psu atapted into the A4k psu casing and had all the caps replaced on the a4k mb.

After 6 weeks (not so much of an issue as I was in a rush at the time) I get the board back only to find I now have NO audio. It appears the fellow repairing board neglected to even test the audio when he was finished his cap replacement.

Im am soooooooo p^ssed off I am about 2 seconds away from simply smashing the whole lot up and being done with it.

Before it gets to that though, anyone have any suggestions as to what the problem may be?
 

AndyLandy

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Erm, Im presently a little p^ssed off...

I sent an a4k MB away to have an audio problem fixed. The audio was crackly and distorted. From the research I did, I found that it could either be failing caps or a failing psu.

So I got an ATX psu atapted into the A4k psu casing and had all the caps replaced on the a4k mb.

After 6 weeks (not so much of an issue as I was in a rush at the time) I get the board back only to find I now have NO audio. It appears the fellow repairing board neglected to even test the audio when he was finished his cap replacement.

Im am soooooooo p^ssed off I am about 2 seconds away from simply smashing the whole lot up and being done with it.

Before it gets to that though, anyone have any suggestions as to what the problem may be?

Sounds like the job hasn't been done correctly. Arm yourself with a multimeter set to continuity mode and buzz out the connections from the new components. Maybe just a dry solder joint has cut out part of the audio circuit.

Who'd you send the board to for repairs? Worth contacting them for support? Anyone worth their salt should be prepared to help you sort it out.
 

abraXXious

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Im sure he would be happy to help out, but it takes weeks to send the board to and fro, it takes bloody ages (which I dont have) to disassemble then reassemble etc an a4k and it costs an arm and a leg in postage.

I simply dont have the patience for this crap.

---------- Post added at 19:12 ---------- Previous post was at 19:11 ----------

I like this "arm yourself with a multimeter" - why the fubar did I bother sending it away then?

I wonder if many mechanics have a car brought in because it is blowing smoke. Fix the problem, but dont bother starting the bastard to actually see whether the problem is fixed or not?!
 

AndyLandy

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Im sure he would be happy to help out, but it takes weeks to send the board to and fro, it takes bloody ages (which I dont have) to disassemble then reassemble etc an a4k and it costs an arm and a leg in postage.

I simply dont have the patience for this crap.

OK, stick with Plan A then. If you're confident that the majority of the work has been done correctly, you should be able to track down any remaining minor faults yourself.

Zetr0 is probably your man right now, he should be able to guide you through the necessary things to look at. Perhaps some hi-res photos of your board might also help the techies on here, particularly of the audio subsystem:

a4kaudio.jpg

(Cropped from stock image on amiga.resource.cx)
 

AndyLandy

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I like this "arm yourself with a multimeter" - why the fubar did I bother sending it away then?

I wonder if many mechanics have a car brought in because it is blowing smoke. Fix the problem, but dont bother starting the bastard to actually see whether the problem is fixed or not?!

I'm not gonna defend how your repair guy has behaved, but you asked for advice on how to proceed. Your options are:
1. Send it back to get it fixed properly, this costs postage and time.
2. See if you can finish the repair job yourself. You might only need a multimeter and a soldering iron. If you don't have these then we're dead in the water (unless you think you'll use them again, so they're worth investing in)
3. Get rid of the board. There's still residual value in a faulty A4000 board, cut your losses and sell it on to someone who's prepared to get it working. Maybe look for a part-ex deal like Hikey often offers.

Options 1 and 3 are pretty self-explanatory. If you want to go down Option 2, there's a wealth of support for you on this board. :)

:grouphug:
 

abraXXious

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Nah, just supremely annoyed, and with work etc I truly do not have the time for this.

We MAY have figured out what the problem could be. When he replaced the caps, he replaced them with values MUCH MUCH higher than the original values. He believes that putting a higher value cap does exactly the same job, it can just handle more voltage. For instance, one cap on the board WAS 6v... it is now 130v - could this be the problem?
 

Cosmos

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Take a good picture of the audio area, and we will see... I'm sure it's some cutted tracks...
 

Tumo007

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You should'nt replace a Cap with a way higher volage valued one. First it usually wont fit! (way bigger) also these have a higher ESR value (internal resistance). Also the 22uF cap that are directly wired to the phono jack MUST be Bi-polar. Did your guy replace all the caps? I've seen Cap for the op-amp power rail fail AFTER the 22uf were replaced. Bottom line replace ALL the cap with the SAME value.
 
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