• Please review our updated Terms and Rules here

IBM AT 5170 motherboard problem

ssdj said:
I just made some progress!! I tried pulling the VGA card out and just have the floppy control card installed. Both floppy drive lights were on after 30 seconds. The computer actually tried to read drive A:
Does that mean the VGA card is causing the problem?
Click to expand...
Per my question in post #15: "With the video card removed, is the POST accessing floppy drive A: (about 30 seconds after power on) ? "

So, yes, the video card is the cause of the problem.

ssdj said:
My video card is trident 256K VGA. It's a 16 bit card.
Click to expand...
Is it the situation that before the problem, the card was in a 16-bit slot, but you now have it in an 8-bit slot?
 
My VGA card is 16 bit in 16 bit slot. The memory expansion card is 8-bit. I tried to use it in the first slot which is a 8-bit slot.

I will describe the situation right now more clearly.
I remove the VGA card and turn on the computer. The computer then makes a long beep and 2 short beeps. After about 30 second, it tries to read drive A and then tries to read drive B and the computer makes 2 short beeps.

So I can conclude that the VGA card is the problem?
 
ssdj said:
I will describe the situation right now more clearly.
I remove the VGA card and turn on the computer. The computer then makes a long beep and 2 short beeps. After about 30 second, it tries to read drive A and then tries to read drive B and the computer makes 2 short beeps.
So I can conclude that the VGA card is the problem?
Click to expand...
Card out

We know that the 5170's POST is being run. You hear POST error beeps, and you see the final act of the POST which is to go through the boot process (includes an attempted boot from A: drive).

Card in

No evidence of POST being run. It could be starting and then stopping somewhere, or maybe it is not running at all. A POST card would inform you as to which.
All we know at this time is that the final act of the POST, the boot process, is not being run.
The fact remains that the insertion of the VGA card is 'stopping' your 5170 motherboard.

So, the VGA card is the cause, the trigger. You've changed nothing and so it is not like there is now some kind of conflict, or anything like that.
 
Can it be possible that the memory card that I tried to install actually damaged the graphic card?

I don't have any ISA graphic card other than this one.
Can anyone sell me one that works with the 5170?
 
ssdj said:
Can it be possible that the memory card that I tried to install actually damaged the graphic card?

I don't have any ISA graphic card other than this one.
Can anyone sell me one that works with the 5170?
Click to expand...

I wouldn't think it would have killed the video card. I would put my money on ESD while working on or handling it, or just a fluke.

I have a Jaton trident chipset 512k ISA card (8 or 16 bit jumperable). I would let it go reasonable if you are interested once I can test it.
 
ssdj said:
I have a 486 board with PCI, VESA, ISA bus. But I am afraid the VGA card may damage the board if it is bad.
Click to expand...
I don't think it works like that. :) Besides, it didn't damage the 286 board. You need to try it so you'll know for sure if it works.
 
Have you tested the power supply output voltages +5 and +12 volts with the video card installed?
Its possible there could be a short on the video card preventing the power supply from working.
It may be a shorted tantalum capacitor, as these types are known to short and cause problems like this.
 
Does the video card have removable or socketted chips ?
If so, it would probably be worth making sure that all the chips on the video card are properly seated.
Removing and replacing it may have disturbed something.
 
ssdj said:
I check the chips on the vga card. They seems alright.

How do I check the output voltages of the power supply unit?
Click to expand...

Multi-meter on the various outputs of the power supply, all of them should be pretty close to their specs, which are typically +3.3, +&-5, and +&-12 volts. Here I found a site that has a good diagram of the AT Power supply pinouts, the site is not in english, but the diagram is.

EDIT: If you find your PSU is failing, there are ATX to AT converters, which are quite useful since ATX power supplies are available just about anywhere, while true AT PSUs are getting to be much more rare
 
Hi everyone!! I think I found what is causing the problem. It is the power supply after all. I used the psu from my 486 to boot up the 5170 and everything works perfect just like before.

Thanks for the help!!!
 
DOS lives on!! said:
So the video card that was originally thought to be the problem isn't faulty?
Click to expand...
I don't think that it is a 'done deal'. For example, what if the video card developed a fault that resulted in it drawing sigificantly more current than normal (e.g. caused by an electrically leaky filter capacitor on the card). That overloads the 5170 PSU, but not the more powerful 486 PSU.
 
I use the video card on my 486 system and it works.

So how should I test it further? Do I need to get another 5170 power supply to test it?

The 5170 works now with the ATX power supply. If I just leave it like this, will it cause problem down the road?
 
You must log in or register to reply here.
Back
Top