15 Oct
2015
15 Oct
'15
10:44 a.m.
I am searching for a CPU card for a 9835 to replace the dead processor
in my 9835A, but a CPU card from a 9845B/C would also be ok. I would
prefer the 9835 card as it would be a drop in replacement but with a
9845 card I would have to transfer over the CPU module. The part number
on the module should be 5061 3001.
Paul. phb.hfx at gmail.com
16 Oct
16 Oct
5:21 a.m.
-----Oorspronkelijk bericht-----
Van: cctalk [mailto:cctalk-bounces at classiccmp.org] Namens Paul Berger
Verzonden: donderdag 15 oktober 2015 16:45
Aan: General Discussion: On-Topic Posts Only
Onderwerp: Processor card for a HP 9835.
I am searching for a CPU card for a 9835 to replace the dead processor in my
9835A, but a CPU card from a 9845B/C would also be ok. I would prefer the
9835 card as it would be a drop in replacement but with a
9845 card I would have to transfer over the CPU module. The part number on
the module should be 5061 3001.
Paul. phb.hfx at gmail.com
Hi Paul,
I think I have a HP 9845 board somewhere, but did you checked the connection between the
processor and the pcb.
It's made by a combination of polymer with gold wire on it. This is the first time I
heard of a bad processor, there is a much higher change of bad connections than of a
defective processor.
The connector principle is the same as in the HP-41C from where it's known to cause
some trouble.
Let me know the outcome if you're sure it's the processor I'll dive in to my
parts stack ;)
-Rik
2:59 p.m.
Hi Rik,
I am pretty sure it is the CPU, the key had fallen out of the monitor
cable and I accidentally plugged it in backwards, and when I turned it I
almost immediately noticed the smell of magic smoke escaping. The +12V
regulator was wrecked, both the 723 and its pass transistor plus a
couple burned foil traces on the power supply board. I have repaired
the power supply and all the voltages are good now, the clock input to
the CPU is good, however the clock outputs are dead. I also fear for
the ROMs in the machine but I can fix that as I had already designed a
ROM card for option ROMs that I could easily modify for the system ROMs.
Paul.
3:46 p.m.
Hi Rik,
As near as I can tell the connections are good, but I am pretty sure it
is the CPU, the key had fallen out of the monitor cable and I
accidentally plugged it in backwards, and when I turned it I almost
immediately noticed the smell of magic smoke escaping. The +12V
regulator was wrecked, both the 723 and its pass transistor plus a
couple burned foil traces on the power supply board. I have repaired
the power supply and all the voltages are good now, the clock input to
the CPU is good, however the clock outputs are dead, and I do not see
any evidence of life from the CPU. From checking after disconnecting
everything it appears that the +12V output went up to more than twice
its rated level. I also fear for the ROMs in the machine but I can fix
that as I had already designed a ROM card for option ROMs that I could
easily modify for the system ROMs. I am still evaluating the full extent
of the damage.
Paul.
5:34 p.m.
Paul,
I'll look for it tomorrow.
Shall we continue this off-list.
-Rik
-----Oorspronkelijk bericht-----
Van: "Paul Berger" <phb.hfx at gmail.com>
Verzonden: ?16-?10-?2015 21:47
Aan: "cctalk at classiccmp.org" <cctalk at classiccmp.org>
Onderwerp: Re: Processor card for a HP 9835.
Hi Rik,
As near as I can tell the connections are good, but I am pretty sure it
is the CPU, the key had fallen out of the monitor cable and I
accidentally plugged it in backwards, and when I turned it I almost
immediately noticed the smell of magic smoke escaping. The +12V
regulator was wrecked, both the 723 and its pass transistor plus a
couple burned foil traces on the power supply board. I have repaired
the power supply and all the voltages are good now, the clock input to
the CPU is good, however the clock outputs are dead, and I do not see
any evidence of life from the CPU. From checking after disconnecting
everything it appears that the +12V output went up to more than twice
its rated level. I also fear for the ROMs in the machine but I can fix
that as I had already designed a ROM card for option ROMs that I could
easily modify for the system ROMs. I am still evaluating the full extent
of the damage.
Paul.
5:39 p.m.
Rik,
Yes off-list will be good, and thanks for responding and checking.
Paul.
On 2015-10-16 6:34 PM, Rik Bos wrote:
Paul,
I'll look for it tomorrow.
Shall we continue this off-list.
-Rik
-----Oorspronkelijk bericht-----
Van: "Paul Berger" <phb.hfx at gmail.com>
Verzonden: ?16-?10-?2015 21:47
Aan: "cctalk at classiccmp.org" <cctalk at classiccmp.org>
Onderwerp: Re: Processor card for a HP 9835.
Hi Rik,
As near as I can tell the connections are good, but I am pretty sure it
is the CPU, the key had fallen out of the monitor cable and I
accidentally plugged it in backwards, and when I turned it I almost
immediately noticed the smell of magic smoke escaping. The +12V
regulator was wrecked, both the 723 and its pass transistor plus a
couple burned foil traces on the power supply board. I have repaired
the power supply and all the voltages are good now, the clock input to
the CPU is good, however the clock outputs are dead, and I do not see
any evidence of life from the CPU. From checking after disconnecting
everything it appears that the +12V output went up to more than twice
its rated level. I also fear for the ROMs in the machine but I can fix
that as I had already designed a ROM card for option ROMs that I could
easily modify for the system ROMs. I am still evaluating the full extent
of the damage.
Paul.
3236
days inactive
3237
days old
5 comments
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hp-fix＠xs4all.nl -
paul.h.berger＠gmail.com -
phb.hfx＠gmail.com