Amiga 3000 power supply repair?

[Astral]

Ok. So I've got two A3000 power supplies here that don't work. I'd like to get them going. I was wondering if some kind person may point me in the right direction of a couple of things to check / replace / repair and so on. Is there common parts to fail that I can check? Obviously a crash-course in electronics would be overboard, and not practical...so just a few pointers might help. I'm handy enough with what I would consider basic to intermediate electronics and soldering and so on...any help appreciated...

[TCMSLP]

Switch Mode PSUs are basically a combination of magic and voodoo.  Theoretically they're easy/cheap to fix but I don't pretend to understand them and the high voltages on the board usually deter me from trying.  

This explains the design and common modes of failure:-

http://www.repairfaq.org/sam/smpsfaq.htm

Good luck!  Remember to sacrifice the appropriate animals at the correct points in the moon's cycle.

Steve

[mingle]

I had the same problem and couldn't get the PSU repaired, so I managed to find and old non-standard ATX power supply with the -5V line and it fitted perfectly inside the A3000 PSU case. I had to resolder the IEC socket, but that was a doddle.

Then I used an ATX-to-A3000 adapter cable - which used to be made by Nathan (Amiga.org = Amigamaniac?) to connect it to the A3000 MB. Worked like a charm.

Here ya go - I just found my old thread:

http://www.amiga.org/forums/showthread.php?t=52357

Mike.

[SpeedGeek]

I successfully repaired my A3000 PSU a few years ago. There were 2 power transistors, a resistor and a small fuse which failed. You need a multi-meter, soldering equipment and a good eye to do this repair.

It's a good idea to check the cooling fan and inspect the electrolytic caps while your at it. With a switching PSU sometimes it's a simple repair and other times it's catastrophic (then your better off to hack in a replacement PSU).

Good luck!

[amigakit]

Due to popular demand from users here, we now sell the Amiga 3000 ATX PSU Adapter


USA Store:
http://www.amigakit.us/product_info.php?products_id=1164

Europe Store:
http://amigakit.leamancomputing.com/catalog/EUR.php?url=product_info.php?products_id=1164

UK Store:
http://amigakit.leamancomputing.com/catalog/GBP.php?url=product_info.php?products_id=1164

Canada Store:
http://amigakit.leamancomputing.com/catalog/CAD.php?url=product_info.php?products_id=1164

[Iggy]

AmigaKit's solution makes the most sense as you can upgrade at the same time.
And don't try to repair a power supply unless you really know what you are doing (they can shock the snot out of you).

[Astral]

I have just ordered, recieved and tested the amigakit adaptor, just to see if the 2 x 3000's actually work before going any further. They do

So now its power supply repair time. I would rather reuse the original supplies if possible. In saying that if I can fit an alernative replacement inside the case in a factory look/operation type setup then that'll be ok.

I'll look over the post more thoroughly this afternoon.

[magnetic]

And don't try to repair a power supply unless you really know what you are doing (they can shock the snot out of you).

200% on that! DO NOT attempt service/repair of ANY psu if you arent a qualified tech.

[Iggy]

200% on that! DO NOT attempt service/repair of ANY psu if you arent a qualified tech.

Actually, any thing with big capacitors is dangerous.
I manage to knock myself flat with a fluorescent light ballast once (left my right arm numb).

[magnetic]

Iggy
I used to do video installations for exhibition in art shows, galleries, and events. I had a friend who used to do assemblage art with old tvs another artist friend of his died from getting shocked in a junkyard trying to remove an old crt from an old tv to salvage the frame. THe tv was from the 60s and the charge stayed on the coil all those years. It stopped his heart and killed him on the spot!

I replaced an Imac (when they first came out) crt and you should have seen the DEATH warnings in the official apple service manual! ( go online and dl it!)