VOGONS


First post, by DrAlis

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Gentle(wo)men, my Compaq 286 SLT is dead to the point of no power light on and switching to a working power supply did not help. So I got out the internal power supply hoping to find something. But I am not good enough at this, so I need your help. There is some green gunk on the contacts (no idea what they do), but aside from that everything looks pretty happy in here. Any ideas what to check for or do? Thank you & kind regards, Alex

P.S.: Ok I connected the power and measured all the PINs on the band connector that goes to the mainboard. The only significant voltage I got was 17.7V (???) vs. the chasis. I was expecting +/-12 or 5 but 17... But at least there seems to be some Power, but the Power Lights are always off. Best.

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Reply 1 of 6, by pentiumspeed

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Pull the three long capacitors first and check their legs for loose leg. Rest should be good.

I had SLT's internal DC to DC converter, one of capacitor had loose leg (rotating). Other end of capacitor's one lead is for holding capacitor in place.

Cheers,

Great Northern aka Canada.

Reply 2 of 6, by DrAlis

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Thank you pentiumspeed, I will try that and report back. To clarify with rotating you mean that you could rotate the leg=wire without resistance? Also, since you know the SLT: I wanted to try to power via the battery port. But I only found out that the rightmost pin is ground and I do not know where to apply the 12V. Do you happen to know how to power over the battery port? Thank you, Alex

Reply 3 of 6, by pentiumspeed

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Yes, weird but true, the leg of one long capacitor removed from board had a leg that turns, round and round.

Find the contact as ground using multi-meter in ohm mode, the one or two contacts are for thermal sensor, other is positive verified using voltage mode.

Cheers,

Great Northern aka Canada.

Reply 4 of 6, by DrAlis

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Thanks again pentiumspeed. Sorry if a dumb question. I found ground. I do not understand how to find positive using voltage mode. Voltages of all other 3 pins are around 0? How do I find positve? Thanks, Alex

Reply 6 of 6, by Croccy22

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Did you even get your slt working?

I have just received a non working one with seemingly the same issue. No power light, and when I checked all the pins from the internal psu there are 2 pins with 18v, but no other voltage.

Matt.