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Compaq SLT 386s/20 power supply pinout

I'm not clear on the question but I'll throw this out there, maybe it will help others.
From my research you could buy a 6 pin dual row connecter from Adafruit and it will fit in the hole side of the Compaq. You'll still need a casing around it for a clean look and to prevent a user from plugging it in upside-down but it does make for a great start. I had started working on a 3D end to fit another less pretty solution. I'll have to look for it.


Adafruit Connector.jpg
 
I understand that you can use dupont connectors, I already have the part. What I want to know is if the original adapter had anything to interface with the two ground pins on the side. See picture below.

1693399160652.png
 
CloudInMyHead said:
Oh wow. I never realized those were grounds, actually never realized those existed. I have a PS I can see if there are any contacts on the plug for those.
Click to expand...
Thanks. I am trying to make as accurate a replica as a can, and I am rebuilding the battery pack so I might hit you up for more info later if you have an actual wall adapter (not the car adapter). But no matter which adapter you have, I am curious about how that interact with those supposed grounds. I almost wonder if they are just for retention and they are only coincidentally grounded (as others have reported, anyway).
 
I have the AC power adapter, not the Car DC one.
Attached is the plug I had started working on. It wasn't designed for the Adafruit connector as I hadn't made that discovery yet. What it could do was take in 6 stranded wire carefully pushed through the back of the plug, one or two strands a time and extended past the other end, then bunched together carefully and pushed back into the receptacle. It was a very tight fit by design. A little super glue would keep them in place. I didn't like the look or the quality of the wires and they weren't available in super long lengths as I'd like. In a pinch though, it's a good idea at least to get power to the Compaq. I didn't print it for looks yet, this ws more of a fitting. Once satisfied I'd increase the resolution and make it pretty, also need to cap the end where the wires come out to the power supply.


3D-Printed vs Actual.jpg
 

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CloudInMyHead said:
I have the AC power adapter, not the Car DC one.
Attached is the plug I had started working on. It wasn't designed for the Adafruit connector as I hadn't made that discovery yet. What it could do was take in 6 stranded wire carefully pushed through the back of the plug, one or two strands a time and extended past the other end, then bunched together carefully and pushed back into the receptacle. It was a very tight fit by design. A little super glue would keep them in place. I didn't like the look or the quality of the wires and they weren't available in super long lengths as I'd like. In a pinch though, it's a good idea at least to get power to the Compaq. I didn't print it for looks yet, this ws more of a fitting. Once satisfied I'd increase the resolution and make it pretty, also need to cap the end where the wires come out to the power supply.


View attachment 1263426
Click to expand...
Can you please do continuity testing on the 18v charge and tell me what pins have continuity? I am wanting to make sure I get the battery charging circuit connected correctly because I will be rebuilding my battery pack as well.
 
Grizzly Adam said:
Can you please do continuity testing on the 18v charge and tell me what pins have continuity? I am wanting to make sure I get the battery charging circuit connected correctly because I will be rebuilding my battery pack as well.
Click to expand...
Sure. I broke my leg a couple of weeks ago but luckily the power supply and voltmeter are accessible by crutch.

Also, if you get the battery case cracked open, please share any tips. I've tried multiple times and never even get a light crack. Wondering if the lid is completely glued to the bottom. I have two or three that I would like rebuilt for my 3 SLTs.
 
CloudInMyHead said:
Sure. I broke my leg a couple of weeks ago but luckily the power supply and voltmeter are accessible by crutch.

Also, if you get the battery case cracked open, please share any tips. I've tried multiple times and never even get a light crack. Wondering if the lid is completely glued to the bottom. I have two or three that I would like rebuilt for my 3 SLTs.
Click to expand...
I saw on a video that it takes a heat gun and a long time to crack into one.
 
Measuring the power out from the cable is harder than expected. I can only assume the output voltage depends on what the battery charging sensors are reading for how low the battery state is in as my voltages read much smaller than expected. My guess is that the power output depends on the voltage read in on the battery sensor lines. I get 6.26 volts out of line 4 in the picture when the power supply is not plugged into the computer. I know this power supply is good as it charges an SLT that has a working battery.
Also, the metal around the plug is producing voltage. I measured +2.5 compared to ground. I do feel voltage when I touch it which is probably not good.

SLT Power Cable Output Voltages.png
Have you read this post?
(1) Compaq SLT/386 or SLT/286 Power Supply Pinout | Vintage Computer Federation Forums (vcfed.org)

Sorry I could not be more helpful.
 
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CloudInMyHead said:
Measuring the power out from the cable is harder than expected. I can only assume the output voltage depends on what the battery charging sensors are reading for how low the battery state is in as my voltages read much smaller than expected. My guess is that the power output depends on the voltage read in on the battery sensor lines. I get 6.26 volts out of line 4 in the picture when the power supply is not plugged into the computer. I know this power supply is good as it charges an SLT that has a working battery.
Also, the metal around the plug is producing voltage. I measured +2.5 compared to ground. I do feel voltage when I touch it which is probably not good.

View attachment 1264318
Have you read this post?
(1) Compaq SLT/386 or SLT/286 Power Supply Pinout | Vintage Computer Federation Forums (vcfed.org)
Click to expand...
Yes I have. I know where the voltages come in, what I am wondering is if there are continuity between any of the pins. Maybe some of them form a bridge to charge the batteries?
 
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