Amiga 3000 power supply, battery damage… and more to come?

[Roger]

Thanks to a good tip I have my Amiga 3000 for a price of € 100,00. That sounds great doesn’t it.  

It’s from the USA and has a other voltage (110 V). So  I bought a voltage converter, maked sure that everything is well connected and…pressed the power button… and yes its… totally dead…  I checked everything (even the voltage out putt  off the converter) and still nothing…  According to the former owner it had to work great…  pvvv…

Well the next step is that I opened it off course to see what is going on (this I had to do in the first place…).  And this is what I discovered… The supply is damaged. I think that some one has put 220V on it and off course the supply  didn’t survive that. The fuse had a meltdown. So toke the power supply apart from the motherboard and started  a experiment. I put some aluminum folie around the fuse because I thought that’s the only problem… Shi..it wasn’t.

:madashell:

The power supply is still dead but it starts to smoke now. The componemt SCK 2R55A becomes to hot and the rest (the fan and output) is also dead.  I will replace the SCK 2R55A this week and I will buy several fuses…  The rest off the supply looks great on the outside. Also there are no traces of things that are broken and nothing smells  burning.   Also the motherboard looks great. Only the battery has leaked! ( I tryed to put a photo here but I just don't see to get it, there should be a photo in the Images gallery by now)

Next time I will open it no matter what, yes I learnt my lesson…(again). Also one of the disk drives is mounted with tape…

Well what can you say… looks the damage serious or can I expect that this Amiga to come alive again? And does anyone has some tips on the power supple?  Or better is there someone who has a spare and wants to sell it if necessary?

Thanks for reading!

[Zac67]

Bridging a fuse with wire or aluminum foil is a VERY bad idea. The fuse not only protects you from starting a fire, it might also protect non-failed components from being killed.

If a fuse fails, replace it with one of the same rating - most of the time it's not only the fuse anyway.

What was left of the PSU is pretty much smoldered now; better get a new one.  :-( You should only attempt a repair if you know pretty exactly what you're doing.

I'd check the board with a PC PSU to see if it's OK. You should take care of the leaked battery asap.

[Roger]

Yes I know... I wass VERY wrong... I just wanted it to work to much... :oops:

The leaked battery is off the board and the damgage is very small.

[Chain]

photo must be approved first and the it will appears here in gallery, dont worry.


remove board off case and check if there isn any shortage. it can be screw or someting which was moved during transport.

when im buying new machine my fist ste is always strip it completely, you never know what parts loose.

[rkauer]

 I have see the battery leakage on your mobo, it's not bad. Simply clean the corroded area with some isopropyl alcohol, melt and suck the solder (mixed with battery leak) out of the board.

 Them, with a scotch brite (or a flier), rub the area (carefully, don't get near traces or chips) until you see the bright copper and pour some solder on it. Clean everything with a soft and dry wipe and that's it.

-----------

 The PSU problem: you can always swap a dead Amiga PSU with a AT peecee one. The only problem is the missing of the "tick" signal.

 The A3000's PSU pin assign is found on pinouts from Russia.

 The peecee AT PSU pinout assignment is here.

 The only one thing you need to modify on the Amiga itself is move the J300 strap (jumper) to position 2-3 (internal tick).

[amiga92570]

If you decide to get rid of the power supply, I will take it. :-)

[Roger]

Thanks for the advice. I will carry it out carefully.  :hammer:

I also located the problem with the supply. It is not the resistance SCK2R55A but the bridge rectifier diodes (RBV-406) that is inside shorted. Rest of the components looks fine… I will replace the bridge rectifier diodes this week and I think the supply will be repaired then… Yes I will use a fuse now…

If I give up hope you (amiga92570) can have it. But will I give up?  :-)

[Roger]

 :hammer:  :banana:  :banana:  :banana:  :banana:  :banana:  :banana:  :banana:  :banana:  :banana:  :banana:  :banana:  :cheers:  :lotsacoffee:  :banana:  :banana:  :banana: Well... Ithink you knows what this means... ITS WORKING!

Evering works... so happy as a child  :-D

Thanks for the advice!