Archived from groups: comp.sys.hp.hardware (
More info?)
Hey Ben,
Thanks a lot for all the info I will follow your advise. The jumper I
was referring to was the 20 pin connector coming from the power supply.
Last year I had another computer fail and I disconnected the 20 pin
connector from the mother board and used a paper clip to connect two of the
pins on the connector and checked the voltages. All the pins were dead,
bought a new power supply and everything worked fine. I just can't
remember what two pin needed to be jumper. If you don't jump the two pins
even a good power supply will test dead.
<ben_myers_spam_me_not @ charter.net (Ben Myers)> wrote in message
news:410f9564.4171820@news.charter.net...
> John,
>
> I am not aware of any motherboard which requires jumpers or connectors to
be set
> differently when the power supply is unplugged. This would be a little
odd, but
> perhaps HP did choose an oddball motherboard.
>
> As a rule, the fans in a system spin only if the motherboard begins
running,
> because the fans either draw their power directly from the motherboard or
they
> are triggered by a circuit on the motherboard.
>
> My best guess is that something is not right with the motherboard, CPU or
> memory.
>
> Unplug the power cord whenever you are working on the innards of a
computer.
>
> If the system is more than two or three years old, replace the C2032 3v
> motherboard battery, and try again. Failed or failing batteries can
create all
> kinds of wierd symptoms. Also, remove and re-install the memory DIMMs.
if one
> of them came loose, this could cause problems.
>
> To troubleshoot further, open up the case, and remove all boards (except a
video
> card, if present), disconnect all external cables (except for keyboard,
mouse
> and monitor), disconnect all power from floppy diskette, hard drive, and
CD-ROM
> drive. Of course, remember where all these things connect up. Doing so
gets
> down to a bare bones motherboard-CPU-memory-video setup. If the
motherboard
> starts up and displays something on the monitor screen, you know the
motherboard
> and power supply are good. If not, then you need more sophisticated
diagnostic
> tools and/or extra parts to determine which component failed. If the
board
> boots up, reconnect the other devices one at a time. If the system fails
to
> boot after you connect up a device, disconnect it. It is likely the cause
of
> failure... Ben Myers
>
> On Tue, 03 Aug 2004 10:54:51 GMT, "John Baiamonte" <donotrespond@all.com>
wrote:
>
> >Hi All,
> > I have a HP Pavilion 7800 that won't boot up. The green light on the
back
> >of the power supply is on. None of the fans spin, nor any of the drives.
> >When I push the start button on the front panel the only thing that
happens
> >is the light on the CD-ROM drive blinks. I am hard of hearing so if any
> >beeps were present I would not hear them.
> > I would like to check the power supply but forgot what two pins on the
> >motherboard connector need to be jumped when the connector is unplugged.
I
> >do remember that they were next to each other, if anyone can tell me I
would
> >be most thankful.
> > Thanks
> > John
> >
> >
>
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