• Please review our updated Terms and Rules here

Help! Micronics/Gateway 2000 486 Motherboard Mysteriously Dies

gatewayrepairs1985

gatewayrepairs1985

Experienced Member
Joined
Dec 10, 2021
Messages
104
Location
South Of Boston, MA
Hi all!

As the VCFED community has been so helpful to me in the past, I thought I'd share this issue I'm having with this motherboard pictured. It's a nice Gateway 486 JX30G 09-00189 motherboard. It was working just fine a couple hours ago, then I took a break for lunch, and I come back to this beep code and no more video! I'm very confused as to what changed from the 40 minutes I spent away from the motherboard, and I can't seem to pinpoint the problem. I looked up beep codes for the Phoenix A486 BIOS but couldn't seem to match any codes with my beeps. I attached the beeps as an audio file here as well. I don't understand how the motherboard just stopped working, and as of now my system is dead. I even stuck a post card in there to see what it said, and it came back with "02 --". How can I fix this problem and restore my board?

Thank you all so much in advance for any help you can provide!

MOBO.jpg
 
I use almost the same Dell motherboard in my ultimate 486 (Was out of a Dell XPS 466V that I've owned since new, but the case was dropped while moving). Check the first stick of ram. Try swapping bank 0 and 1.
 
twolazy said:
I use almost the same Dell motherboard in my ultimate 486 (Was out of a Dell XPS 466V that I've owned since new, but the case was dropped while moving). Check the first stick of ram. Try swapping bank 0 and 1.
Click to expand...
Hey @twolazy, thanks for the reply!

I did exactly what you said. Even took both RAM sticks out and tried booting. Same beeps, same no video. Any other ideas? Still very confused on what happened here.
 
Next pull the tag ram cache chip and see if it boots... Its the sole cache chip next to the VLB slots.
 
Last edited:
bostonvintage1993 said:
I even stuck a post card in there to see what it said, and it came back with "02 --".
Click to expand...
Is that [02][--] consistent?

I ask because, if you have the POST card shown in the 'Example of a modern POST card' section of [here], then I would expect your readout to be [02][01], i.e. before POST code 02 was produced, POST code 01 was produced.

bostonvintage1993 said:
I looked up beep codes for the Phoenix A486 BIOS but couldn't seem to match any codes with my beeps. I attached the beeps as an audio file here as well.
Click to expand...
I listened to the MP3 file. Those do not sound like error beeps to me. Error beeps are normally a tone of a particular frequency. And their length is way too long - they don't need to be that long.
 
I would recommend hosing all of the slots/connectors down with Deoxit gold, as well as the RAM contacts and give them a good workout afterwards. Can't tell you how many times old computer parts of mine stopped working solely because a slot or connector had ever so slightly tarnished pins that caused a weak enough connection to make it not work.

It could always be a more complex fault, like a lifted leg on an IC somewhere, but best to do the easy stuff first.
 
modem7 said:
Is that [02][--] consistent?

I ask because, if you have the POST card shown in the 'Example of a modern POST card' section of [here], then I would expect your readout to be [02][01], i.e. before POST code 02 was produced, POST code 01 was produced.


I listened to the MP3 file. Those do not sound like error beeps to me. Error beeps are normally a tone of a particular frequency. And their length is way too long - they don't need to be that long.
Click to expand...
Hey @modem7,

Thanks for the reply! Yes, I have the modern POST card and the [02][--] is consistent. When I power on the motherboard, it shows [--][--] for about a second and then shows [02][--] while the beeps play and after they are done. I agree that the beeps did not sound like error codes - not sure what they are.
 
GiGaBiTe said:
I would recommend hosing all of the slots/connectors down with Deoxit gold, as well as the RAM contacts and give them a good workout afterwards. Can't tell you how many times old computer parts of mine stopped working solely because a slot or connector had ever so slightly tarnished pins that caused a weak enough connection to make it not work.

It could always be a more complex fault, like a lifted leg on an IC somewhere, but best to do the easy stuff first.
Click to expand...
Hey @GiGaBiTe!

Thanks for the advice! I ordered a can of deoxit gold so when it comes in I’ll update you!
 
So I noticed some light corrosion on the motherboard so I applied some vinegar. No I’m getting a different error code each time I try to boot. I turned the board on after I applied the vinegar and it worked - for only one boot! The board started fine and I was able to set some CMOS settings, but when I rebooted I got a new error, no beeps, and no video. Now, I get a [03][02] on the POST card, then it changes to a [A0][09] and stays there. Maybe @modem7 can help shed some light on what the problem is? I have no clue why the board keeps working and then not working when I try to boot!
 
Okay, I’ve made an observation. When I press down on/wiggle the traditional AT power connector, sometimes I can get the board to boot. However, I can never get the reset button to successfully reboot the board. I have to turn off the machine, mess around with the AT power connector, and then try it again. Anybody have any ideas on how I can fix this?
 
bostonvintage1993 said:
Now, I get a [03][02] on the POST card, ...
Click to expand...
POST code 02 followed by 03.

bostonvintage1993 said:
.. then it changes to a [A0][09] and stays there.
Click to expand...
POST code 09 followed by 0A.

POST codes 04 to 08 may have flashed passed so fast that you didn't see them. The modern POST cards with two 7-segment displays usually have buttons that allow the owner to step backwards and forwards through previously received codes, and so, using those buttons, you may see that card did receive them. When you do that, the left display is the count, and the right display is the POST code.

But that won't really tell you much.

bostonvintage1993 said:
... then it changes to a [A0][09] and stays there.
Click to expand...
The POST was merrily progressing along, and then all of a sudden, the motherboard stopped ?

bostonvintage1993 said:
So I noticed some light corrosion on the motherboard so I applied some vinegar. No I’m getting a different error code each time I try to boot
Click to expand...
"Corrosion". That could very well be the problem.

A secondary induced problem: I don't know how conductive vinegar is, but if it went under a chip/s, and it is still sitting there (resting up against pins), it might be causing a problem. Or perhaps something that you used to remove the vinegar.
 
modem7 said:
POST code 02 followed by 03.


POST code 09 followed by 0A.

POST codes 04 to 08 may have flashed passed so fast that you didn't see them. The modern POST cards with two 7-segment displays usually have buttons that allow the owner to step backwards and forwards through previously received codes, and so, using those buttons, you may see that card did receive them. When you do that, the left display is the count, and the right display is the POST code.

But that won't really tell you much.


The POST was merrily progressing along, and then all of a sudden, the motherboard stopped ?


"Corrosion". That could very well be the problem.

A secondary induced problem: I don't know how conductive vinegar is, but if it went under a chip/s, and it is still sitting there (resting up against pins), it might be causing a problem. Or perhaps something that you used to remove the vinegar.
Click to expand...
Hi,

Thanks for the advice about the POST card. Yes, the motherboard POST seems to be going just fine and then stops. When I got this motherboard about two years ago, the previous owner said there was some battery leakage that he had cleaned off. I didn’t think much of it since the board worked fine and had been working steadily until yesterday. This morning, I thought I saw some mild corrosion still on the external battery connector so I applied some vinegar.

I just don’t understand how sometimes I can get the board to boot and sometimes I can’t. It just seems so random. And when I can get the board going, I can never reboot to save my CMOS settings or hit the reset button without it failing again. It gets stuck on “Rebooting . . .”.

Have you any clue what is tripping the board up at the [A0][09]?
 
Last edited:
bostonvintage1993 said:
When I got this motherboard about two years ago, the previous owner said there was some battery leakage that he had cleaned off. I didn’t think much of it since the board worked fine and had been working steadily until yesterday. This morning, I thought I saw some mild corrosion still on the external battery connector so I applied some vinegar.
Click to expand...
In my opinion, NiCd battery leakage [photo] is insidious. Look up the definition of that word to gain an appreciation of its meaning.

Have a very good inspection of your motherboard; the 'leakage' may have got to places that are well hidden.

See the motherboard at [here], one which suffered from such leakage on a card. Not only did the motherboard have a few faulty chips right near the card's slot, but there were damaged vias as well - you guessed it, around the general area of the slot. The green wiring is my bypassing of the faulty vias. No track damage. That motherboard would have probably stopped working at the time when the first chip, or via, was damaged. The remaining damage happened after that. The faulty chips near the card's slot suggested to me that the leakage worked its way into the chips.

I still have a friend's faulty IBM 5170 motherboard, from years ago. The battery had leaked, resulting in (indirect) damage to the area around the keyboard connector. That was repaired and then the motherboard worked. But only for a while. I suspect that even though I had thoroughly cleaned the affected area of the motherboard, that the 'leakage' had already made its way into bits (i.e. my cleaning affected the surface only). Something like that. It's just a hypothesis.

I am not saying that your symptoms are caused by damage resulting from NiCd battery leakage, but such damage is certainly a possibility.

You are seeing changing symptoms after physical influence is applied. Coincidence, or is this a damaged track/via/joint !

Maybe the Deoxit will be the fix.
 
bostonvintage1993 said:
Have you any clue what is tripping the board up at the [A0][09]?
Click to expand...
Stopping at 0A.
(09 is simply the previous code.)

First, you would need to find an authoritative reference for your BIOS, in order to be very sure what the 0A means.

That can be tricky. One example of many: My IBM 5170 motherboard stops at the POST code of 02. I go to the 'IBM AT BIOS' section of www.bioscentral.com and from there discover that 02 equates to 'BIOS ROM checksum tested'. But that is wrong, for two reasons:
1. Per [here], IBM actually changed the meaning of 02 during the lifetime of the IBM 5170; and
2. Even for the 1985 dated revisions, the description is wrong. The checksum wasn't successfully tested - it is about to be tested.

Let us assume that the 0A in your BIOS means {About to execute PIT test}. Possible causes might be:
- Chip containing the PIT is faulty.
- Chip containing the PIT is good, but a chip that supports PIT operation is faulty.
- Open circuit trace (which includes vias).
 
You must log in or register to reply here.
Back
Top