[vcf-midatlantic] cranky 5150 - PART 2

[william degnan]

Set the MOBO to minimum RAM, remove all but video controller report result

Bill Degnan
twitter: billdeg
vintagecomputer.net
On Nov 5, 2016 5:05 PM, "Steven Michelsen via vcf-midatlantic" <
vcf-midatlantic at lists.vintagecomputerfederation.org> wrote:

> Uh oh.  After writing the post below I read the appropriate
> minuszerodegrees
> page, that suggested among other things, "Faulty motherboard - bad solder
> joint on keyboard connector".  So I took a look - here's what I found.  Not
> promising.  But fixable!  Does this look like the culprit?  But what about
> the memory errors?
>
>
>
> https://www.youtube.com/watch?v=3A9uULoyJgk
>
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> From: Steven Michelsen [mailto:stevenm at optonline.net]
> Sent: Saturday, November 05, 2016 4:55 PM
> To: 'vcf-midatlantic' <vcf-midatlantic at lists.vintagecomputerfederation.org
> >
> Subject: cranky 5150
>
>
>
> I thought for once I could get a new IBM 5150 and NOT have to come crawling
> to the group for advice, but noooo..
>
>
>
> Just got an ebay 5150.  I couldn't resist - it was relatively local, and
> included a 5151 monitor (but no keyboard), for a decent price.  I have a
> keyboard, so no worries.  Took the top off to peek inside to confirm
> everything was seated, etc.  I started it (with the top off) and got a
> keyboard error (301).  I discovered that my keyboard was set on AT instead
> of XT.  Flipped that switch and viola, the 5150 booted with a Dos 2.11
> disk.
> Poked around the disk, ran a Basic file that happened to be on it, tested
> the "B" drive, formatted a disk - it's all good.  I even booted a few times
> with no issue.
>
>
>
> I put the lid back on and started it again.  This time I get this.
>
>
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> 40FF
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> . and the PC is beeping away, long beeps that do not stop!
>
>
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> I restart again and get this.
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> 40FF
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> 201 301
>
>
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> This time there's no beeping, it just displays the msg.  The disk drive was
> read from briefly, then nothing.
>
>
>
> I pull out what appears to be a memory expansion card.  Here
> <https://dl.dropboxusercontent.com/u/65762317/forums/IBM_5150_RAM_
> board.jpg>
> 's a picture of it.  I started it without the card and get this.
>
>
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> 40D0
>
>
>
> I took another look at that RAM card and found THIS on the back
> <https://dl.dropboxusercontent.com/u/65762317/forums/5150_bug.jpg> !  My
> PC
> had a bug.  Anyway, cleaning that up didn't help.  I replaced the card,
> started it and got yet another, different 40xx error.
>
>
>
> OK, where do I go from here?  The darn thing worked at one point today; why
> not all the time?  I have looked for unseated chips, cards and cables, as
> least as far as I could without pulling a floppy drive, and found that
> everything is secure.
>
>
>
> Thanks as always,
>
> Steve
>
>