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macpokerstars

macrumors regular
Original poster
Sep 29, 2010
101
1
Hi everyone,

I got the Macintosh from 1984 on ebay from a US seller. I live in the UK so voltage is 220V.

Apparently Macs, at that time, did not have a 110-220V converter and I did not know that. US devices were 110V only.

So when I turned on my Mac on 220V, it snapped, making a "BLOOP" noise and does not turn on anymore.

Do you know if it is just a fuse that snapped or did I ruin the whole computer?

Please let me know you thoughts, as I'm quite depressed at the moment.

Thanks a lot

Alex
 
I think the only thing that is affected is the power board inside, all you have to do is open it up check the fuse and see if there are any blown up components and replace them with the right ones.
 
Sorry to hear your tale. :(

First, a warning. The fuse will be blown, but replacing it could do more damage to components. On the Mac 128 to Mac Plus Power/Sweep board there is little protection from an event such as this and there WILL be other components damaged (but only on the Power/Sweep board).

You'll need to be experienced in repairing Switch Mode Power Supplies to get it going again. You might be lucky in that only the bridge rectifier has gone, or un-lucky in that the PWM circuit has taken a hit too.

Your alternative is to hunt out a cheap Mac128, Mac512K, Mac512Ke or MacPlus and swap the board.

USA sold early compacts were 120V only. Countries with 220-240V actually used a Power/Sweep board that was "convertible" (referred to as "International"), via a jumper soldered on the Power/Sweep board.

Don't despair! You're not the first, and you won't be the last! :)
 
Hi afroAnt and MacTech68,

Thanks a lot for your help!

MacTech, how can I know if it's only the bridge rectifier that's gone or if it's the whole PWM? Do I need some measurement device?

Thanks again for reassuring me!

Alex
 
Sorry to hear your tale. I nearly did the same on a TAM, the voltage switch is in the Sub Woofer, just remembered at the last minute to check!

Hope you get it working again.
 
Hi afroAnt and MacTech68,

Thanks a lot for your help!

MacTech, how can I know if it's only the bridge rectifier that's gone or if it's the whole PWM? Do I need some measurement device?

Thanks again for reassuring me!

Alex

Yes, you'll need a multimeter or Digital Multimeter (DMM). However, if you're asking these sorts of questions I would advise against attempting this sort of repair yourself. SMPSs are lethal devices working or not.

Please take this as a friendly warning. :)

Sometimes I wish I had a TARDIS. :D
 
Yes, you'll need a multimeter or Digital Multimeter (DMM). However, if you're asking these sorts of questions I would advise against attempting this sort of repair yourself. SMPSs are lethal devices working or not.

Please take this as a friendly warning. :)

Sometimes I wish I had a TARDIS. :D

Haha, so do I.. Anyway, i'll take your advice seriously and will probably go see a repairman.

Thanks for the valuable info.

Alex
 
Yikes, I was in a similar situation with an HP DV7, except the it actually caught fire (and melted the plastics) when I plugged it in. A word of advice, a cisco 48V power supply is NOT a suitable replacement for a 12v laptop power supply.

Anyway, I wound up replacing several FETs, diodes and a Power Management chip. The first fet was easy, since it was scorched, the second needed to be tested for resistance, and the PMU chip was pinpointed with an infrared temperature gun. The PMU chip was being shorted out, causing it to get extremely hot. Even though I didn't have any way to test the chip, the infrared gun pretty much told me exactly what chip replace. Sourced another chip from a parts board (MOQ was 1000 chips!), and the laptop has been up and running for a while now.
 
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