• Please review our updated Terms and Rules here

Burned traces and label on ISA XT CF adapter

seaken

Experienced Member
Joined
Jun 20, 2016
Messages
293
Location
Shokan, New York
In another thread I was working on setting up a CF card on my Tandy 1000HD. With the forums help I was able to get that computer successfully working with a CF card as the new hard drive. I ended up purchasing two different XT CF adapters because the first one I bought took up two slots and I only had one slot left in the Tandy 1000HD. I bought the second adapter that only used the one slot and I was able to take this other adapter that requires the ribbon cable and bracket and put it in another computer. It worked initially. Until this morning.

This other computer is a Leading Edge Model D DC-2010E. The CF adapter is the Lo-tech ISA XT CF adapter rev. 3 by TexElec. Along with the add-on ribbon/bracket CF adapter. While I was learning how to set this card adapter up with my Tandy 1000HD I moved it over to this Model D to test it, using another CF card. It all worked. But I did have to disable the RTC on this Model D using a motherboard pin setting. After successfully using this card on this Model D I put it back in the Tandy 1000HD and it worked in that machine for about a week until I got the second card. Then I moved it back to this Model D and had it working with a CF card and booting DOS 5.0, until this morning.

This morning I turned on this Model D and it would not post. The power light came on the monitor and the PS fan was on but no post. I left it on for awhile and when I came back it was still powered on but no post and a blank screen. I turned it off and started to open the case. When I moved the monitor off the case I thought I smelled something burnt. I thout it might be the monitor with some dust. But when I went to remove the XT CF adapter I noticed it was VERY hot. I removed the card from the ISA slot and placed it on the table. Then I rebooted the machine and this time it posted. I had suspected the XT CF card was interfering with the post and this seemed to confirm it.

When I went back to the XT CF card it was cool but I noticed a mark on one of the ISA interface pins and it looked like the traces on the card were discolored. I turned it over and noticed the lable was black (the label used to be white). It dawned on me that this was what I was smelling. The label was burning.

So, now I am wondering if this card is burned out and irreperably damaged. Never having experienced this type of thing before I am wodering what will happen if I put this card into another computer. I had thought I would put this card into my Packard Bell VX88 and use it there. But now I am wondering if I should try that or if I muight damage the VX88 in the process.

The card did not seem to damage the Model D. Once I took it out the computer boots up from floppy and works normally. When I got this Model D I was unable to get the hard drive to work and I could not get the controller to work. I am now wondering if this Model D had a bad ISA slot and I ended up burning this XT CF card in that slot. But I don't know how to test this theory without risking another card.

Or, was is likely the XT CF card itself and not the fault of the Model D? Again, I don't really know how to test this without risking damaging something else.

Is it possible that the Model D was at fault and damaged the XT CF card? Or do you think it's more likely that the XT CF card itself was the source of the "burn"?

Do you think the burned label, extreme heat, and discolored traces means the XT CF card is dead? Or might it still work?

Here's some photos:

Seaken
 

Attachments

  • IMG_20220925_122137260.jpg
    IMG_20220925_122137260.jpg
    366.8 KB · Views: 55
  • IMG_20220925_122150113.jpg
    IMG_20220925_122150113.jpg
    797 KB · Views: 55
  • IMG_20220925_122203049.jpg
    IMG_20220925_122203049.jpg
    1.1 MB · Views: 56

Malc

Veteran Member
Joined
Jul 16, 2009
Messages
2,225
Location
UK
Do you think the burned label, extreme heat, and discolored traces means the XT CF card is dead?
Yep, Looking at the solder side of the adapter, Middle pic and just above resistor R3 it looks like the leg of C1 connected to the 5v rail is missing ???, Or is that just an illusion, Has that leg been shorted against something else ?.
 

modem7

Veteran Member
Joined
May 29, 2006
Messages
8,535
Location
Melbourne, Australia
At first, I thought, "The ROM is is the wrong way", the kind of thing that I would do, but [here] indicates otherwise.
The ROM label turning black indicates that the ROM got very hot. I'm sure it's "toast".

Did the card get plugged in back-to-front ?
 
Last edited:

seaken

Experienced Member
Joined
Jun 20, 2016
Messages
293
Location
Shokan, New York
No I was very careful to plug the card in the right way. Following the direction on the label.

And it worked for awhile.

Too bad. Have any of you heard of this type of thing happening, assuming the board is plugged in correctly, where the board got fried in an ISA slot on an old PC/XT Clone? I'm wondwering if this is just an unlucky instance and if I try again with another card it should not happen again.

Is the board a gonner? or can I just replace the ROM chip?

Seaken
 

T-R-A

Veteran Member
Joined
May 17, 2009
Messages
590
Location
Western NC
Is the board a gonner? or can I just replace the ROM chip?
Some serious current had to have been put through those traces to do that. Personally, I wouldn't try that board again until I was certain I had investigated everything else on the board (and if something external could have caused it). You may take out something other than the board if you don't find the cause. I do board repair 40+ hours a week and I certainly wouldn't just plug another chip in and go....
 

seaken

Experienced Member
Joined
Jun 20, 2016
Messages
293
Location
Shokan, New York
Well, I tend to agree with @T-R-A about investigating everything on the board. But I am not that patient and I moved on to something else and set this board in the drawer.

As it turns out, it lives! I was playing with my NEC Powermate 286 and trying to get a hard drive working. I decided to use just the CF adapter and cable attached to the NEC's hard drive interface. I could not get it to work. I tried several old IDE hard drives and none of them would work either. I think the hard drive interface in the NEC is defective. Anyway, I got frustrated that nothing was working and I decided, what the hell, I'm going to put that XT-IDE card in and see what happens.

It worked! I baby-sat it for awhile to make sure it was not going to catch on fire or anything. But the card works and it does not get hot at all. So, I now have the CF "hard drive" in my NEC 286. I left it on my bench for several days and kept checking it to make sure nothing was going to overheat without me nearby. It never overheated again and it is working reliably.

I'm pretty confident at this point that the problem was coming from the Model D's ISA slot. Unfortunately, I did not mark the slot. Nor do I know how to troubleshoot the ISA slots. But I will put a note in that machine to remind me there may be a problem. In the meantime I am using it as a two floppy system with no problems.

And I finally got my "hard drive" in the NEC Powermate 296. I will share more about what I am doing with that machine in another post.

Seaken
 

NeXT

Veteran Member
Joined
Oct 22, 2008
Messages
7,254
Location
Kamloops, BC, Canada
ISA pin B03 is +5v and the roasting traces don't go far beyond the 74HCT688 and the resistor network. Without thinking too much about it and the fact it somehow still works all I can think is the board went into latch-up which killed all traffic on the ISA bus and began dumping heat.
 

seaken

Experienced Member
Joined
Jun 20, 2016
Messages
293
Location
Shokan, New York
Ok, thanks for the tip. It is working, and so far I see no signs of any trouble when using it in the NEC. I'll keep watching for any ill effects but I think it is going to be fine as my new hard drive. Now I am thinking of redoing my CF cards to use the smaller one [32MB] in the Tandy 1000HD and the larger one(s) [1000MB] in the NEC.

Seaken
 
Top