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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: strim on September 22, 2010, 10:41:27 PM
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Hi!
Today I managed to break my recently restored Amiga 3000 :mad: . I was in a hurry, so I tried plugging serial cable when computer was powered on. How stupid that was... Ofcourse, short-circuit on serial port pins ocurred, and Amiga powered down. Now I can't even turn it on.
I see that PSU fan does spin for a second or two when I push the power button. Then it stops and literally nothing happens. If I cycle the power it's the same.
Power supply is dead, I presume :( . Does A3000 PSU have some kind of fuse? Any ideas on fixing it?
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Hi!
Today I managed to break my recently restored Amiga 3000 :mad: . I was in a hurry, so I tried plugging serial cable when computer was powered on. How stupid that was... Ofcourse, short-circuit on serial port pins ocurred, and Amiga powered down. Now I can't even turn it on.
I see that PSU fan does spin for a second or two when I push the power button. Then it stops and literally nothing happens. If I cycle the power it's the same.
Power supply is dead, I presume :( . Does A3000 PSU have some kind of fuse? Any ideas on fixing it?
There should be a fuse in the PSU, but if the fans spinning up for a few seconds it doesn't seem likely that the fuse has blown, looks like it could be a bit more nasty than that... :(
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Disconnect the PSU from the motherboard and try powering it up, if the PSU turns on and runs normally (and powers the HD, etc,) it's probably something on the board.
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oh man NEVER EVER plug ANYTHING into your A3000 with the power on, it may have fried more than the serial port :( Good luck. the other poster was right disconnect the psu and try to power some hds or a cd drive or so..
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I agree with disconnecting the mobo... something on it may have shorted. It draws too much current and the power supply shuts down to protect itself. Note that it's possible that the drives alone may not be enough of a load for the 3000 power supply, and it still won't power up, so you learn nothing. I've seen it on pc supplies, but don't recall ever trying it with a 3000. I used to put dummy loads on the 5v in those cases.
Anyway, check out the serial port level shifters. at U304 and U305. I've seen those fail on a 2000, and short the -12 to +12v & give the same symptom. It's a place to start anyway.
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Guys, thanks for all the suggestions. First thing I tried was disconnecting PSU from main board. However symptoms are the same - few spins of a fan, then nothing.
I see that there is no "power good" signal in A3000 PSU, so it should just work after pressing the button, even if mainboard is not connected. Right?
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Strim
Yes, its should work and spin the fan up and power devices without being connected to mb. its not a pc psu :P
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It might need some load, like a hard drive or something for it to come on.
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I suggest you also check the two 8520 (CIA) chips which handle the serial, parallel, keyboard and other Amiga I/O activities.
Too bad for you! :(
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Fortunately only PSU was broken (dead voltage regulator). Now my PSU is fixed and everything else is working! Including CIAs and serial port :-).
(http://c0ff33.net/~rkujawa/alive.png)
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Glad to hear this! You are lucky in the extreme. Take this to heart, and stop plugging stuff in while it's powered on!
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Another happy landing.
- Obi-Wan Kenobi