Once upon a time, in the land of 90s internet, used to live a page that had everything you ever wanted to know about all the early Compaq Portables. ... ... unfortunately my brain won't cough up any other names involved or where it was hosted to help with a waybackmachine search... tried oocities (geocities archive) but nothing looks likely.
Unicorn herding operations are proceeding, but all the totes of hens teeth and barrels of rocking horse poop give them plenty of hiding spots.
@bitwrangler -- there's seasip[dot]info but it's not got that pinout, I checked.
@drosse1meyer -- that's a subtly different connector, physically. It's 14 pins long (incl key pin), rather than 13 pins, and definitely a different pinout. I described the pin groupings for the 13pin connector above -- I'm afraid they don't match.
Anyone else? @pentiumspeed? You want to chime in...?
Also -- does anyone have a source of PLCC 12MHz 286 chips? I've been getting help here and there from Foone on Twitter but he doesn't have those (I asked, he checked) -- or, from what I gather, the pinout I need.
I'm not entirely sure about the current sense pin. But it reads +5v most of the time and is required to behave for the power supply to start spinning, so that's my guess. I don't think it is a simple 5v supply.
In the power supply (identical on 386 and III) there's a particularly troublesome tantalum bead that's driven near its limit and is prone to failure. I don't have the PS open at the moment but it sits on the main pcb between the plain pcb riser and the 'bent heatsink riser' next to it -- in your photo #014257 it is the (orange) cap hidden behind the red cap on the riser. I think it is a 15uf 25v (they're always blown up and I've never seen an intact one, but playing with the jigsaw of epoxy you get after a tant explodes suggests 15uf, and replacing with a 15uf tant makes the psu work again... I'm very confident about the 25v). I always replace with a 35v. You can't get in to it replace without taking out the risers, which is always going to be a pain -- the best solution is to cut out the cap and then solder the replacement to the underside of the board (mind polarity!) -- there's plenty of room for it when the psu is reassembled.
This next bit probably won't apply to you, but on the 386 there are two troublesome caps C47 and C49, near the power supply connector on the main board. They're on the 12v line but rated for 15v, so like to degrade to short (even without exploding, as the power supply tends to limit current automatically -- symptoms of this are the fan not spinning up with the power supply connected to mainboard, but spinning up fine when it is disconnected). These caps are 10uf 15v. Indeed, the board has got loads of 10uf 15v tants on it, but most are running at 5v and are usually fine. Replace c47 and c49 with 25v tants. I imagine that there'll be similar 12v line caps on the III, but you'll have to work out where they are yourself (that's what continuity meters are for!).
C2 (near the hard drive power connector) also seems to be liable to explode. It also sits on the 12v lines (+12v) and is a 10uf 15v tantalum bead. Replace with 25v.
Sorry for responding to an older thread, but responding directly to this pinout: the only thing am still fuzzy about is what exactly are we supposed to connect to the current sense line. Power Good? +12v? 0v? Nothing?
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I have another Compaq (a Portable II that doesn't work and is not going to be restored, because "I don't want to talk about it!")
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Hey, in case you are up for any parts exchanging, I also have a Portable II - well, actually I have two of them - one is restorable, the other is not, really. There are still some parts I need, and maybe I have extra of something your machine needs?
