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heALer
October 8th, 2017, 12:44 AM
I picked up an old 286 computer made by Mitsubishi. sperry 3137-00.
The psu seems to be broken so I was going to replace it. But its not the normal AT-connector. I took some pictures. Anyone know if there is any converters or is it Mitsubishis own design?
The fan doesnt spin up. And I got 1.5v on the red wires from the psu, think it suppose to be 5v?

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modem7
October 8th, 2017, 02:20 AM
The fan doesnt spin up. And I got 1.5v on the red wires from the psu, think it suppose to be 5v?
To start and run, some PSU's need to be loaded. Was the measurement made when the PSU was plugged into the motherboard.

heALer
October 8th, 2017, 02:41 AM
To start and run, some PSU's need to be loaded. Was the measurement made when the PSU was plugged into the motherboard.

It was unplugged. I plugged it in. I get 1.0v now on the red,
Yellow 2.4v plugged in, brown -2.4v, blue -2.4v, white nothing

Stone
October 8th, 2017, 04:08 AM
A shorted component on the motherboard can also cause the PSU to malfunction.

heALer
October 8th, 2017, 05:38 AM
Yes maybe it is that..
Forgot to unplug the molex to diskdrive and hd. Now when nothing is plugged in I got:
Red 3.0v
yellow 7.2v
blue -7.8v
brown -5v

Everything plugged in:
Red 1.0v
Yellow 2.4v
Blue -3.0v
Brown -1.2v

What does the white cable do?

Is it correct that it should be
Red 5v
Brown -5v
Yellow 12v
Blue -12v ?

I thinking of trying a different psu and see how it goes


Does the psu start correctly if the psu-fan is broken? 3 cables goes to the fan.

KenEG
October 8th, 2017, 07:02 AM
You should probably start by checking or replacing all of the capacitors in the PSU. Also check it the fan spins freely. If not, lube or replace it. By checking part numbers in the PSU, you should be able to figure out what the voltages should be.

heALer
October 8th, 2017, 08:06 AM
You should probably start by checking or replacing all of the capacitors in the PSU. Also check it the fan spins freely. If not, lube or replace it. By checking part numbers in the PSU, you should be able to figure out what the voltages should be.

Ok thanks, I will try to recap it, I think the capacitors is the problem

heALer
October 30th, 2017, 01:26 AM
I got this thing running now after recap. It boots up. But something is wrong with the keyboard. An error shows up E-KB20. The computer has a keylock, its some kind of a microswitch with a white and green cable coming to it, its labeled ss-01gl111.
In dosmode the keyboard is all messed up, no key works the way it should, if i press A for example it shows just weird output like "Z^Z"
Dont know if the keylock is the problem, can I bypass the ss-01gl111? No keys works if its locked, but weird output when unlocked. Strange noise from the pc speaker when turn on with keylock unlocked. Have to lock it then unlock it again to stop the noise, see the video.

The keyboard is working in other computers and I have tried another keyboard, all the same.

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Videoclip:

https://www.google.se/url?sa=t&source=web&rct=j&url=https://www.youtube.com/watch%3Fv%3DBIRFhnMAMwM&ved=0ahUKEwivz4GXiJjXAhVCMZoKHeNJBdsQo7QBCBwwAA&usg=AOvVaw0mzjTEVFbM_Z6eHgLUtxbg

KenEG
October 30th, 2017, 03:09 AM
Is the keyboard the right on for the computer. If the PSU is proprietary, maybe the keyboard is also.

KC9UDX
October 30th, 2017, 03:28 AM
A key lock generally won't cause incorrect keypresses.

heALer
October 30th, 2017, 04:13 AM
A key lock generally won't cause incorrect keypresses.

Maybe it is something wrong with the keyboard controll 8042 chip. Pulled it out from the socket and cleaned it, put it back but no luck.
See if I can test one from another pc, if it is socket.

heALer
October 30th, 2017, 04:17 AM
A key lock generally won't cause incorrect keypresses.

Can I just put a jumper between white and green cable on the switch to bypass it, or do anyone know how it operates?

heALer
October 30th, 2017, 04:25 AM
Is the keyboard the right on for the computer. If the PSU is proprietary, maybe the keyboard is also.

Hm maybe you are right, dont have the original keyboard so cant test it. I tried a normal 5 pin AT keyboard.
The caps or numlock keys dont lit, only flashes once when power on.

heALer
October 30th, 2017, 04:47 AM
Took another 8042 chip and now everything works :)

KC9UDX
October 30th, 2017, 05:17 AM
Can I just put a jumper between white and green cable on the switch to bypass it, or do anyone know how it operates?

To answer your question, yes. But glad you got it figured out already.