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Compaq Portable 386

Max IBM5150

Member
Joined
Oct 12, 2011
Messages
33
Location
Louisiana, United States
I bought a dead Compaq Portable 386 with the expansion box last week and after about 26 hours of tinkering with it, and a DOS Re-install it now boots to DOS 6.22.


After all of this, only 2 problems that I can determine at this time remain:

1.The internal display has a red vertical line going through the screen.

2. When I try to use a VGA card in the expansion box, I get no video output, it uses the internal screen and the video cards BIOS doesn't get displayed when the computer starts.

What I want to do with this machine is use it as the portable it was meant to be, and as general use 386 machine with Windows 3.11, VGA Graphics via external display, and a Sound Card.

The VGA card is a 16-bit ISA EGA/VGA combo cards it was manufactured by Ahead.

These are the only pictures I can find of it.

http://www.ebay.com/itm/Ahead-VGA-W...892?pt=LH_DefaultDomain_0&hash=item1e64bc9adc

The only difference between this one and mine is that mine does not have the empty sockets for more video RAM, there is just a blank PCB there with nothing soldered to it.

The Machine has a 100MB Hard Disk, 6MB of Memory, and the 80387SX Co-Processor installed.

Any help or insight on these problems would be very appreciated.

Max
 
1.The internal display has a red vertical line going through the screen.
Photo required.

2. When I try to use a VGA card in the expansion box, I get no video output, it uses the internal screen and the video cards BIOS doesn't get displayed when the computer starts.
What I want to do with this machine is use it as the portable it was meant to be, and as general use 386 machine with Windows 3.11, VGA Graphics via external display, and a Sound Card.
A lot of info at http://support.microsoft.com/kb/89014

The bit that's interesting is, "Some Compaq portable displays are reconfigured for MDA so that they can function with a third-party EGA or VGA display adapter mounted in the expansion chassis; an adapter conflict occurs unless these displays are reconfigured. "

So, from that, have you tried setting the portable's display to MDA ("This is accomplished by setting the E23 jumper to 2-3").
 
Here are some photos of the screen

Video 6 0 00 00-01.jpg

Video 7 0 00 00-02.jpg

Video 8 0 00 00-01.jpg

I have tried cleaning both ends of the video cable, but that didn't help any.


I did set the jumper E23 to 2-3/MDA, but the problem is unchanged.

Here is a picture of the video card:

Video 9 0 00 00-01.jpg

My guess is that the switches near the video connectors have something to do with this.

Oh and here is a picture of the soundcard I plan to use.

Video 11 0 00 00-01.jpg

If I need to post any more info please let me know.
 
Do you have the means to test the video card in a different computer?

Yes I can test it in my IBM/AT


To me, that looks like failure of the video electronics (driving the plasma grid).

It turns out that I have a plasma controller board from a Compaq Portable 3, but it looks like that the screens were made by two different people hence they are incompatable. I guess I would have to replace the screen (or find a compatable screen controller board) to fix this issue?
 
Yes I can test it in my IBM/AT
Let us know the results once you've done the test.

It turns out that I have a plasma controller board from a Compaq Portable 3, but it looks like that the screens were made by two different people hence they are incompatable. I guess I would have to replace the screen (or find a compatable screen controller board) to fix this issue?
Have you looked for possible bad solder joints.
 
Dead lines in the plasma panel cannot be repaired.

Not to sound dumb but I'm curious why you want a video card installed considering you already have an internal screen.
 
Not to sound dumb but I'm curious why you want a video card installed considering you already have an internal screen.

The Internal Display is MDA/CGA only I want to be able to use this machine as a desktop-like computer as well as a portable. When I am using this machine as a desktop, I would like to have VGA so I could run more programs than if I was limited to MDA/CGA.

It seems like the switches on the VGA card are for changing the refresh rate and sync rates. All I got from switching them was garbled scrolling static. If I leave them all off, It will display normally.

Basically I am wondering if there is a setting to turn the internal display off, or to recognize the VGA card as the primary display.
 
You can download the service manual for the Portable 386 here: [urlhttp://www.manualslib.com/manual/273076/Hp-Compaq-386.html[/url] (jumper settings are towards the end).

I don't have my Portable 386 any more, but iirc there was more to it than just changing the jumper to MDA mode. You might have to change a BIOS setting so that the colour display is the primary.

Another option is to just use the Compaq's enhanced 640x400 CGA mode. It's a decent enough resolution for most Windows 3.x software. It's compatible with the AT&T 6300's 640x400 mode, so if you set the computer type to "AT&T 6300" when installing windows then you should then be able to use the extra mode.
 
I tried the BIOS Setup disk, and I did not see an option to use an external graphics card.

I read in the manual that in order to use an external card, you needed to set it as primary via switches on the board .

I am guessing that any old ISA VGA card won't work, that it would need to have a compatible switch setting in order to be accessed.

I suppose using the Enhanced CGA mode would be a viable option in this case. (I really didn't think Windows 3.11 had drivers for this- until now.)
 
My Portable 386 had an ATI VGA Wonder crammed in it and it seemed to work out of the box. It must be some sort of configuration problem.
 
I did read in another thread that the CompaqDOS 3.31 is the version which allows you to configure BIOS settings for the 386/20. I've had a similar experience with the 386/20 that I have which had the CMOS battery die. After replacing it, and rigging up a 3.5" floppy drive to install DOS 2.1 from (I didn't have 5.25" media to used the original 5.25" drive), I could not get anything to appear on the screen. After removing the expansion pack (which I later found contained the ATI Wonder card) the screen came back on. Having read through this thread, I'll make an attempt to install CompaqDOS and try to get into the BIOS and hopefully run the video card.....but I need to get the power supply fixed first.
Perhaps 'neXT' can confirm that he ran CompaqDOS.....this will give us another clue.
 
Can't comment on the addition of a VGA card, the internal plasma 640x400 has always been perfectly adequate for all the computing I do on my Portable III (same layout as Portable 386, its just a 286). Windows 3.1 runs VERY well on the plasma.

As for the line, that's pretty normal with plasmas of this age. Not much you can do about it, but replace the panel, but any compatible panel will also be 25 years old, and will also likely be near failure. As annoying as it is, pretty much just got to deal with it. I am lucky on mine its, an intermittent line, seems to only set in after its been running for a while (I am assuming heat is a factor). I have never attempted a repair, because plasmas are so fragile, I would be more likely to destroy it, than fix it.
 
Okay, looking at the picture again, *carefully*, I wonder if you might have some dreck on one of the pcb's somewhere. Reason being, the "line" actually isn't a line, it appears to be a column of excessive brightness.
patscc
 
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