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Apple ][ GS - PSU help

CheeseMeister

Member
Joined
Oct 27, 2015
Messages
13
Alright,

So I did a really, really silly thing and I'm going to admit to it right up front so I don't get a hundred lectures about it.

I ordered a Apple II GS / ][ GS / whatever, the only ones I could find on ebay were from the US so I ordered one and, well, it never occurred to me that the PSU wouldn't be able to take a UK charge from the mains. Anyway, I suppose you could say, I done ****ed up. This was about two years when I was really only just getting into this stuff, so I'd ask you to go easy on me.

What I want to know is, is the whole unit bricked? Can I get a new PSU, particularly one that's designed for UK voltages? Can I repair the current PSU? Will I banished from the vintage computer forums for my stupidity?

Answers to any or all of these questions most welcome.

Maki
 

george

Experienced Member
Joined
Apr 1, 2011
Messages
409
Some models of //gs PSUs can be converted to 220V mains input while others can only be used with an additional step-down transformer. With 99% probability you burned ony the PSU itself which it is repairable by a qualified technician. The //gs PSU outputs several standard voltages so it can be replaced with non-original PSU but mechanically this will not fit into a //GS case...
 

retrogear

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I agree with George that the damage would probably only be the power supply itself. The internal fuse would blow instantaneously. In fact, it may only be the fuse that is bad but might be a soldered in one.
There is some discussion and photos of how certain power supplies could be converted from 110 to 220 by simply removing a wire link:
http://www.applefritter.com/content/apple-iigs-psu-110v-220v

Larry G
 

NeXT

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I agree with George that the damage would probably only be the power supply itself. The internal fuse would blow instantaneously. In fact, it may only be the fuse that is bad but might be a soldered in one.
There is some discussion and photos of how certain power supplies could be converted from 110 to 220 by simply removing a wire link:
http://www.applefritter.com/content/apple-iigs-psu-110v-220v

Larry G

Typically when you feed 240v to a 120v device the primary side takes the biggest hit and the secondary side and the computer itself survives. Before the fuse blows the rectifier might explode along with any capacitors not expecting 240v, including load and pulldown resistors. The worst case scenario is the primary windings on the transformer will blow open and a surge might take out the voltage monitoring and regulation on the secondary side and by that point you are better off looking for a new power supply.
 

retrogear

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True, but I would still look around with an ohmmeter before tossing it. //gs power supplies along with all vintage parts are only going to get more unobtainium.

Larry G
 

CheeseMeister

Member
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Oct 27, 2015
Messages
13
Thanks for the replies guys, sounds like the PSU might not be a total write off then. I wonder if it is repairable and convertible. I have no idea where I'd find a qualified technician who knows about ye olde vintage computer parts. But I'd definitely be interested, it would definitely make me feel less guilty if I could salvage it. I have to say it didn't smoke or make any bad smells like PSU's that have blown up on me for no discernible reason in the past, so I feel maybe the fuse went quickly. It only made the tiniest flash I wouldn't even have seen if I weren't looking directly at it.

Did the IIGS ever come out in the UK? I've literally never seen one in all the time I've checked on ebay.
 

retrogear

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>It would be unusual in a power supply like that for the transformer to go before the fuse.
And if the transformer failed, the output transistor on the primary would have a collector to emitter short, guaranteed, so an ohmmeter could determine that.
I was just saying if you have an ohmmeter, check for major shorts on rectifiers and transistors then if ok, try a fuse. If no meter, go for the fuse anyway.
You have nothing to lose but a fuse :p

Larry G
 

amauget

Experienced Member
Joined
Mar 9, 2011
Messages
84
Hi all,

It's easy to know if your Apple IIGS PSU is convertible.
It must be a Dynacomp branded one. And the screws must be on the side of the PSU, not on the top. You just have to remove a single wire.
See this photo album for more details.

By the past, I also plugged a 110V clone Apple II PSU into 220V.
I had to replace the fuse, a couple of resistors and transistors (especially the big "TO-3" one) to get it running again.
But the PSU was "220V ready".
 

CheeseMeister

Member
Joined
Oct 27, 2015
Messages
13
Lucky for me, I've just had a look and I have the DynaComp PSU. I've found a company that are prepared to attempt a repair for a fairly reasonable price, so looks like this IIGS may be coming back from the dead. Thanks for all your help. Now to grab one of those CFFA3000's...
 

retrogear

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Good. If they manage to repair the PS, report back here what parts? I own a IIgs so it would be good info - thanks.

Larry G
 
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