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Request foor help on 5170 Mobo

Thanks modem7. I got my type 3 going but my type 1 has got me stumped. Even using the Supersoft diagnostics I can't get any video so it's making it tougher to troubleshoot.
 
Well I think I have finally gave up on the early 5170 motherboard. I have spent a lot of time on this and still have no video with the Supersoft diagnostics with card known to work on my type 3 and Supersoft. Guess it's time to realize I been beat and put it in the junk pile for parts usage. Was really hoping to save this particular board.

I have tried following the Sam's type 1 book but I have found way too many inconsistencies that I couldn't trust it. There are many instances where the prints do not match the logic table. Besides that, it does state that all readings are taken with unit sitting idle with no disk in the drive...and displaying press F1 to continue. I never could get that far. I have been able to get to post code 0605 with the IBM BIOS which says DMA issues, replaced DMA IC's but still get 0605.

If anybody has any more ideas that I haven't tried, please deal free to throw them at me.

Thanks for all your help folks.
 
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Well I haven't given up just yet. I am curious though, I did replace the keyboard controller U126 and I keep reading somewhere about programming this IC. I did not do this and was wondering if this IC is pre-programmed, as I have read from other sources, or do I have to do that? Could that be part of my problem?
 
Sabertooth said:
Well I haven't given up just yet. I am curious though, I did replace the keyboard controller U126 and I keep reading somewhere about programming this IC. I did not do this and was wondering if this IC is pre-programmed, as I have read from other sources, or do I have to do that?
Click to expand...
If you were to go to Intel, and ask them about their 8042 (or 8742) keyboard controller, they would say something like, "The 8042/8742 is not a keyboard controller. It is a multipurpose microcontroller. You, the designer/engineer, program it to perform the function you want; a controller in a microwave oven, a jellybean counter, a keyboard controller, etc."

For the IBM 5170 motherboard, the 8042/8742 has been programmed with IBM code that makes the 8042/8742 function as a 'keyboard controller', one specifically suitable for a 5170 motherboard.

If someone goes to eBay, or wherever, and simply buy any 8042 (or 8742) they find, they could be buying an unprogrammed one, or a jellybean counter, or ...

Sabertooth said:
Could that be part of my problem?
Click to expand...
Part, but not all. For example, if an unprogrammed 8042/8742 was put onto the 5170 motherboard, I cannot see how that would cause a timer error.

I have just now experimented with a type 3 motherboard. I replaced the functional 'keyboard controller' with an unprogrammed 8742. The Supersoft/Landmark diagnostic ran error free up to the PROTECTED MODE CPU test, then it hung at that test (hung, because on a 5170 motherboard, a functional 'keyboard controller' is required to reset the CPU during that test).
 
modem7 said:
If you were to go to Intel, and ask them about their 8042 (or 8742) keyboard controller, they would say something like, "The 8042/8742 is not a keyboard controller. It is a multipurpose microcontroller. You, the designer/engineer, program it to perform the function you want; a controller in a microwave oven, a jellybean counter, a keyboard controller, etc."

For the IBM 5170 motherboard, the 8042/8742 has been programmed with IBM code that makes the 8042/8742 function as a 'keyboard controller', one specifically suitable for a 5170 motherboard.

If someone goes to eBay, or wherever, and simply buy any 8042 (or 8742) they find, they could be buying an unprogrammed one, or a jellybean counter, or ...


Part, but not all. For example, if an unprogrammed 8042/8742 was put onto the 5170 motherboard, I cannot see how that would cause a timer error.

I have just now experimented with a type 3 motherboard. I replaced the functional 'keyboard controller' with an unprogrammed 8742. The Supersoft/Landmark diagnostic ran error free up to the PROTECTED MODE CPU test, then it hung at that test (hung, because on a 5170 motherboard, a functional 'keyboard controller' is required to reset the CPU during that test).
Click to expand...

Great information. I will have to check into this but I don't think my programmer can do the 8042 and might have to purchase another.
 
Hello , can you make a video with post card to see all the codes that motherboard generate with IBM bios?
 
mborza said:
Hello , can you make a video with post card to see all the codes that motherboard generate with IBM bios?
Click to expand...

Well since I don't get very far it would be easier just to say. With the IBM BIOS, from the last code to the first, it is as follows
06 05 04 03 02 01

I have changed out the DMA IC's so my issue is a supporting IC somewhere.

If you would still like a video, I can sure do that.
 
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