Amiga.org
Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Kremlar on May 13, 2016, 04:23:51 AM
-
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!!!
-
Are you using powered or unpowered speakers?
-
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?
-
and also failing caps
My vote goes to drying caps.
Check the audio circuitry and which ones are involved.
-
My vote goes to drying caps.
Check the audio circuitry and which ones are involved.
I hope they have dried and not leaked. :(
-
My vote goes to drying caps.
Check the audio circuitry and which ones are involved.
Likely the caps on the audio board?
-
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.
-
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!
-
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?
-
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.
-
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
-
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.
-
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...
-
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.
-
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 ;)
-
Sending my 4000T components to Acill for recapping! :)
I found these 2 articles that I thought might be applicable to me:
Audio Cap Issue (using different capacitors):
http://joj.home.texas.net/amigacap.html
3640 Cap Issue (reversing capacitors):
http://joj.home.texas.net/amiga/amiga00.html
Are these fixes that I should ask Acill to take care of at the same time?
Anything else I should know about when getting my 4000T recapped?
Thanks for everyone's input, and thanks especially to Acill for offering his service!!
-
(http://www.techav.com/misc/amiga4000t/empty.jpg)
Kind of sad. :(
-
Mmmm... naked A4000T, lay on its side no less! I am studying every hole and crevice in this wonderous beast.
-
I know about reversing the 3640 caps, no problem. I will get it done and back to you soon. I love my A4000T and understand how you feel!
-
I know about reversing the 3640 caps, no problem. I will get it done and back to you soon. I love my A4000T and understand how you feel!
Haha! Take your time! :)
-
Here is whats going in since I am using my personal cap kit you are getting an amazing deal, lol! Also give others a good idea of the cost involved to do it right.
http://www.digikey.com/short/3pbwnr
-
Here is whats going in since I am using my personal cap kit you are getting an amazing deal, lol! Also give others a good idea of the cost involved to do it right.
http://www.digikey.com/short/3pbwnr
:)
That's awesome! Per my email please charge me what you think is fair when everything is done. It's well worth it to me to spend a bit more $ on high quality caps!
-
Thanks to Acill for the quick turnaround, reasonable price and great work recapping my 4000T and all daughterboards! Everything fired right up and my audio issue (low volume) is fixed! Great communication from Acill during the whole process, highly recommended to anyone else looking for recap work!!
-
It was a pleasure to get it working again properly! I LOVE getting a machine in and firing it up to a perfectly working like new experience.
-
Thanks to Acill for the quick turnaround, reasonable price and great work recapping my 4000T and all daughterboards! Everything fired right up and my audio issue (low volume) is fixed! Great communication from Acill during the whole process, highly recommended to anyone else looking for recap work!!
He's right up the road. I have to pull my 4000T apart and it's full. I have limited space, must put parts somewhere as I go. Better part of a week I think. Oh, save money too!
I used to make good money. Not now since this pres not so good ;-(
Chris
-
@ Kremlar
great to hear and thanks to Acill for keeping another miggy working in top top shape :banana:
btw, please change the thread title to solved.
-
He's right up the road. I have to pull my 4000T apart and it's full. I have limited space, must put parts somewhere as I go. Better part of a week I think. Oh, save money too!
I used to make good money. Not now since this pres not so good ;-(
Chris
Just a heads up on the 4000T and cost. If its a full recap which includes the 3 modules as well I have to charge more than the usual $68 for an A4000. the caps alone cost that, so in order to make something for my time I have to charge $110. I cant justify putting the crappy caps in an A4000T to bring the price down.
-
Just a heads up on the 4000T and cost. If its a full recap which includes the 3 modules as well I have to charge more than the usual $68 for an A4000. the caps alone cost that, so in order to make something for my time I have to charge $110. I cant justify putting the crappy caps in an A4000T to bring the price down.
Well worth it to get everything done, and done right!
-
Just a heads up on the 4000T and cost. If its a full recap which includes the 3 modules as well I have to charge more than the usual $68 for an A4000. the caps alone cost that, so in order to make something for my time I have to charge $110. I cant justify putting the crappy caps in an A4000T to bring the price down.
No no, Must do it right! This one is my baby. Got a good deal when I bought it and will NOT let it go to crap!
Chris