Problems with IBM 5150 Power
cclist at sydex.com
Mon Jul 27 22:20:01 CDT 2009
On 27 Jul 2009 at 19:03, Joe Giliberti wrote:
> Can anyone suggest what to do next? I have PDFs of the Hardware
> Maintaince manual and the technical service manual.
I assume you're re-seated all of the socketed chips and probed a bit
with a scope or logic probe to see that the processor is at least
ticking over--and you've checked your display switch settings.
There are inexpensive POST cards that can display any POST error
codes, but if you're not even getting a beep, that doesn't sound
It's not unknown for the old mask-programmed 8Kx8 ROMs to develop bit
If you suspect this, you can either use a 2764-type 28-pin EPROM and
rig up an adapter to fit the 24-pin socket or pick up some Motorola
68764 EPROMs and program them and use them directly. Amazingly,
during the 5150's heyday, they were near unobtainum, but I've seen
them offered NOS for something like $6 the each lately.
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