PDA

View Full Version : Unisys PW2 300 (80286, 10mhz) Keyboard controller failure



grastukker
December 5th, 2013, 04:30 AM
Hello everyone,


I'm Jeroen, I am 28 years old and I live in Hengelo, a little town in holland, near the german border.

I have an old Unisys pw2 computer and would like to know more about it.
My uncle gave me this computer in the late 90's and it still worked, untill a neighbor came by with a keyboard and would like to know if it still worked.
I plugged it in the Unisys, and started it. The keyboard wire was getting a bit warm(not hot) so i turned it off immediately. From that moment, the computer didn't work anymore (I know, it was a stupid action, but I was twelve at the time and didn't had any expirience then).
It still started, but did not respond on it's original keyboard anymore.
It gave the following report:

keyboard failure
keyboard controller failure

0,64k Base Memory, 00000k Extended
Gate A20 failure
Decreasing available memory

Does anybody know how to get this old Unisys back to live?
I searched the interned with this failure and think that the keyboard controller chip might possibly be dead ??
The specs from the Chip are: Intel P8042AH 2219
3911-9037

On the edge of the Mainboard stands: PW2 300 CPU BOARD

I appreciate every information with regard to this old machine, also its age, etc etc.

Robin4
December 5th, 2013, 03:42 PM
The last url doesnt work.. Better reupload it to an image server.

barythrin
December 5th, 2013, 04:33 PM
Well, I guess as expected a Gate A20 (http://ibm-pc.org/manuals/PC-FAQ.txt) error also seems to be a bad keyboard controller. Does it by chance use a card for the keyboard controller or is that built in to the motherboard? You might have to start looking for blown capacitors, etc at this point.

smeezekitty
December 5th, 2013, 05:30 PM
If there was heat involved you might look for any visibly burnt components.

grastukker
December 6th, 2013, 02:05 AM
Thanks, I didn't noticed it! It was the picture from this page: http://www.angelfire.com/ri2/gadgett/garagesale.html
It's still on this page, two photo's from the same model I have.

grastukker
December 6th, 2013, 02:20 AM
Well, I guess as expected a Gate A20 (http://ibm-pc.org/manuals/PC-FAQ.txt) error also seems to be a bad keyboard controller. Does it by chance use a card for the keyboard controller or is that built in to the motherboard? You might have to start looking for blown capacitors, etc at this point.

The keyboard controller is build in to the motherboard. I already started the computer without the keyboard controller chip on the board, and it didn't made any difference, stil the same report. Can it be that it's not the keyboard controller chip that died, but other parts that are damaged?
The keyboard controller chip is a P8042AH from intel

grastukker
December 6th, 2013, 09:11 AM
I made some photo's today.

The keyboard controller chip:

http://i837.photobucket.com/albums/zz298/grastukker/Unisys%20PW2%20300/051220132831_zps919ea206.jpg


Motherboard type:

http://i837.photobucket.com/albums/zz298/grastukker/Unisys%20PW2%20300/031220132781_zps8cb92e98.jpg


And the place where the keyboardcontroller houses:

http://i837.photobucket.com/albums/zz298/grastukker/Unisys%20PW2%20300/061220132861_zps402cbffe.jpg

http://i837.photobucket.com/albums/zz298/grastukker/Unisys%20PW2%20300/061220132871_zpsb4187e71.jpg

http://i837.photobucket.com/albums/zz298/grastukker/Unisys%20PW2%20300/061220132871_zpsf7d40d04.jpg

grastukker
December 6th, 2013, 11:08 AM
I figured out something else. I got two different startup screens. one without keyboard plugged in, and then the computer is counting it's memory like it used to do:

http://i837.photobucket.com/albums/zz298/grastukker/061220132941_zps56407001.jpg


And the screen that I get when I startup the computer with keyboard plugged in:

http://i837.photobucket.com/albums/zz298/grastukker/061220132931_zps1a438013.jpg


So it seems that the keyboard still has some influence on the startup of the computer. How can this be explained?

grastukker
December 7th, 2013, 03:55 AM
The last url doesnt work.. Better reupload it to an image server.

thanks, I noticed it to late. (I already posted a responce, but it seems that I can't get new replies on this topic? even if I reply myself, it's still not placed in my topic, what did I do wrong?)

modem7
December 7th, 2013, 12:12 PM
even if I reply myself, it's still not placed in my topic, what did I do wrong?
Read http://www.vintage-computer.com/vcforum/showthread.php?39961-New-users-needing-moderator-approval

Pepinno
December 7th, 2013, 12:45 PM
keyboard failure
keyboard controller failure

That sounds bad. I think you need to open the case and see if there is visible damage near the keyboard connector.

grastukker
December 8th, 2013, 10:38 AM
Read http://www.vintage-computer.com/vcforum/showthread.php?39961-New-users-needing-moderator-approval

They already solved the problem! I guess they were to busy. Thanks! So the photo's ar also on this topic now!

H-A-L-9000
December 9th, 2013, 10:40 AM
You could check if F1 is blown.

QBiN
January 29th, 2015, 09:34 AM
I don't mean to bump an old thread, but did you ever figure this out?

I grew up with that same model of computer, and couldn't help but ask.

grastukker
November 17th, 2015, 10:56 AM
yes, I called Unisys Netherlands, where an old engineer told me what the problem could be.
He told me about a green(as green as a frog) fuse that looks like a tiny capacitor. on one of the photo's you can see what i mean. The engineer told me, that if you have a short circuit in your keyboard, that little green fuse is the first thing that will blow up. I meassured resistance, and yes, it was dead! The local electronics shop here in hengelo(TessaTronic) had those old green fuses still in stock, so i bought one, exchanged it with the dead one(soldered) and it was alive after many years!!! it responds on the keyboard!! thank you Unisys netherlands! The only thing that I still need is Bios-software, cause my battery was also empty and replaced that also. but i don't have the original bios software. Does anybody know how I can get this software?

modem7
November 19th, 2015, 11:05 PM
The only thing that I still need is Bios-software, cause my battery was also empty and replaced that also. but i don't have the original bios software. Does anybody know how I can get this software?
Maybe a generic SETUP tool, like GSETUP.EXE from [here (http://www.minuszerodegrees.net/5170/setup/5170_gsetup.htm)], will work.

Chuck(G)
November 20th, 2015, 07:52 AM
For what it's worth, the term of art for one of those fuses is a "Picofuse".