Amiga 4000T low volume

[Kremlar]

Having an issue with my Amiga 4000T that I'd like to resolve.  I know it sounds odd but I've had this unit for a couple of years and have never used it for audio, so I don't know if it was ever working.  I also want to make sure I'm not doing something stupid.

Audio volume out of the RCA jacks is very low.  With my speakers jacked up to 100% the volume is barely as loud as when I enable the internal speaker.  It doesn't necessarily sound distorted that I notice, just low.

I tried 2 sets of speakers and 2 audio cables so I know that's not the issue.  I tried playing a MOD from Workbench and also booting to a game disk - same problem.

I tried checking power supply voltage at the motherboard connector and am getting -12.16V, 11.97V and 5.14V.

I've found posts indicating low volume could be caused by a bad power supply and also failing caps.  

Is there anything simple I'm missing?  I believe I have a couple of spare AT power supplies I can try.  What else can I try?

Thanks!!!

[Oldsmobile_Mike]

Are you using powered or unpowered speakers?

[Kremlar]

Are you using powered or unpowered speakers?

Powered speakers.  

I just tried the headphone mini-jack (didn't notice it there at first), and the audio volume is great out of there!

So, I'm getting low volume only out of the RCA jacks.  Headphone jack sounds great.

I assume that's not normal?  Could it still be a power supply?

[jltursan]

and also failing caps

My vote goes to drying caps.

Check the audio circuitry and which ones are involved.

[paul1981]

My vote goes to drying caps.

Check the audio circuitry and which ones are involved.

I hope they have dried and not leaked.

[Kremlar]

My vote goes to drying caps.

Check the audio circuitry and which ones are involved.

Likely the caps on the audio board?

[Acill]

A4000T audio comes off a board. Ive seen several on ebay lately too. You can look and see if the one I saw the other day is still available. It was like $60 with no bids. I picked up a couple spares recently myself for under $65.

[BozzerBigD]

AV Module capicitors need replacing. Ask the Amiga Center in France JJB will sort this out and you'll only need to send him the one small module!

[paul1981]

A4000T audio comes off a board. Ive seen several on ebay lately too. You can look and see if the one I saw the other day is still available. It was like $60 with no bids. I picked up a couple spares recently myself for under $65.

Did they make more of these modules than A4000T's then?

[Acill]

Did they make more of these modules than A4000T's then?

I'm sure they did. I can do a recap on it for you if you like. I charge $40 to do it. It may not solve the issue though but is worth doing if it does have bad caps on it.

[icbrkr]

Even if you're bad at soldering, it doesn't take much effort to replace the caps.  

Here's how you can usually tell if they're bad (I'm working on restoring my 4000T):

https://www.facebook.com/photo.php?fbid=10207387837632080&set=a.10207387819071616.1073741878.1170907465&type=3&theater

[Kremlar]

Even if you're bad at soldering, it doesn't take much effort to replace the caps.  

Here's how you can usually tell if they're bad (I'm working on restoring my 4000T):

https://www.facebook.com/photo.php?fbid=10207387837632080&set=a.10207387819071616.1073741878.1170907465&type=3&theater

Thanks for the post.  Looking at a high res photo of my audio board I think those exact same caps are failing on mine as well.

I've replaced other caps before but not these SMD caps.

[QuikSanz]

Thanks for the post.  Looking at a high res photo of my audio board I think those exact same caps are failing on mine as well.

I've replaced other caps before but not these SMD caps.

At least unlike those resistors around it, you have something to grab on to...

[icbrkr]

Right - they break off easy and you can easily solder some new ones on.

If I remember right, those are the final 2 amplifier caps which means if you're having issues with the volume, they're probably the ones you need to replace.

[mechy]

Having an issue with my Amiga 4000T that I'd like to resolve.  I know it sounds odd but I've had this unit for a couple of years and have never used it for audio, so I don't know if it was ever working.  I also want to make sure I'm not doing something stupid.

Audio volume out of the RCA jacks is very low.  With my speakers jacked up to 100% the volume is barely as loud as when I enable the internal speaker.  It doesn't necessarily sound distorted that I notice, just low.

I tried 2 sets of speakers and 2 audio cables so I know that's not the issue.  I tried playing a MOD from Workbench and also booting to a game disk - same problem.

I tried checking power supply voltage at the motherboard connector and am getting -12.16V, 11.97V and 5.14V.

I've found posts indicating low volume could be caused by a bad power supply and also failing caps.  

Is there anything simple I'm missing?  I believe I have a couple of spare AT power supplies I can try.  What else can I try?

Thanks!!!

Its the caps leaking most likely. time to do it all