HP Pavilion a712n - It will not POST (No video, No beeps, Solid HDDLed, k/b not responding)

Hi guys/gals:
I am a comp. tech here in NY and I have a customers PC with a
rather strange issue.

Issue: PC is not booting. It will not even POST. Monitor is blank/in
stand-by. Hard Drives and Fans are all working. Hard Drive light is
solid.

The PC is a Pavilion a712n Desktop-PC. Pentium 4, IDE drives, 512mb
ddr memory, 1 cdr 1 cd drive, only 1 PCI slot occupied with a modem.
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Here are some of the PC's symtoms when first turned on:
- No Video (Monitor will not even switch off standby/light is yellow)
- No POST Beeps at all.
- All keyboard lights (num/caps/scroll) initially flash when powered
on but thereafter no keys respond, not even caps or num.
- Solid Hard Drive Light (No blinking at all, it's solid. The drive
does spin up and go through it's initital startup/self-test? process
(short series of clicking).
- Green LED on Power Supply blinks once on startup (Apparently normal
because I tested the PC with 2 other good PSUs.
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Here are some procedures I tried, all of which resulted in no change.
No Beeps, POST. No Video. K/B Not Responding. (these may not be in
order)

[Video]
- Tried other monitors.
- Tried Adding a basic PCI video card and connecting the monitor
through there.
[Power]
- Tried 2 other power supplies I had. 1 was HP, one was from a
dell (but compatible)

[Hard Drive/Other Drive]
- Tried booting without the hard drive or any IDE devices.

[Motherboard]
- Checked and Reseated all cables for m/b, IDE drives, front
connectors)
- Reseated PCI card (modem), I tried without the card as well.
- Stripped down the PC to the least components required to boot.
- Tried it without memory, Tried it with new memory.
- Tried replacing the cpu with the same exact CPU from my stock
- Ensured heat sink was properly connected and used new thermal
paste.
- Cleaned/Dusted off entire motherboard and PSU (of course with
power and clk. batt removed)
- Tried removing the motherboard from the case and running it on
non-conducting surface (no shorting)
- No Visible Motherboard/IC Problems (Carefully inspected
motherboard under worklight/magnifier to look for blown/leaking caps
or solder bridges between pins.)

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I have come to the conclusion that the motherboard is blown but I
would like your help/confirmation before I have the customer spend
$200+ for a new HP board.

I would greatly appreciate help from anyone with experiance on these
systems. Also, if indeed it's the motherboard does anyone know of a
replacement board non-oem that will fit in the HP case.

Thank you so very much guys/gals!

 

Yep, sounds like the motherboard is hosed... Ben Myers

 

Thanks Ben -- I appreciate it. I would hate to have a customer spend
$200 for a new OEM/HP motherboard if I am wrong. Would anyone know if
there is a non-hp board that will fit in this hp case?
- Fred

 

According to the HP web site, the motherboard is the MS-6577 v4 (Gamila 2), made
by MicroStar (UGH!).

The board has a very much standard mATX form factor, except it does have both
internal and external Firewire connectors. If your client does not use
Firewire, you would want to get a board with an Intel 845GV chipset and built-in
Intel Extreme Graphics, to make it 1000% easier for Windows XP to boot up and
run. Audio is Realtek ALC658 and Ethernet is a Realtek chip also. If you
change the chipset, Windows will complain bitterly and probably not boot at all,
even in safe mode. You may still have to re-authenticate (or whatever that
stupid word is) Windows via the Microsoft web site. Use Keyfinder to change
the product key first, to match the sticker on the side of the computer.

You should be able to find a good quality 845GV chipset board for maybe $50 max
on eBay or from one of the many sellers of older motherboards... Ben Myers

 

Wow! I was expecting a "no it won't work". Not only did you give me
the answer both myself and my customer wanted to hear, but you went in
to much detail and saved me hours of my time. Otherwise, my next plan
involved going to a computer store to fit motherboards and see which
might work, then reloading everything (not expecting chipset drivers
to be alike). I initially thought it looked like a regular micro atx
too but then on the internet a few people posted only hp motherboards
would fit in hp cases, thanks for the clarification. As for firewire,
no they are not using the firewire, just the USB, ethernet, ps2 kb/
mouse, monitor and I believe that's it.

Thank you very very much!
If there is anything I can do for you, e-mail me
busywithbiz @ gmail .com

 

Hi Ben
Quick question, I found a similar board but it says for "Willamette
and Northwood, 1.4 to 2.8 GHz and higher", would that be compatible
with this computers (pavilion a712n) p4 processor?

Thanks!

-Fred

 

found it -- I apologize!

 

Yes. IIRC, your system has a Socket 478 Celeron, well-suited for a great many
older Socket 478 boards... Ben Myers

 

Thanks Ben -- For some reason I thought it was a P4!

 

Most of your questions could have been answered by looking on the HP
website. I suggest you do so.

 

Fred,

I do not know whether or not to say "my bad". The HP web site, never a marvel
of clarity says:

Pentium4 (N) 2.8 GHz:
400 MHz Front side bus
Socket 478

As far as I know, Pentium 4's were never made in 2.8GHz speeds with 400 (!!!)
MHz FSB. What is a "Pentium4 (N)" anyway? I think HP screwed up. If the
processor really is a Pentium 4, its front side bus speed is 533MHz. If the
processor is a Celeron, its front side bus speed is 400MHz. The HP motherboard
supports both with the 845GV chipset. The system ships with PC2700 memory,
supporting both bus speeds.

So much for consulting the HP web site for "everything" you want to know about
the A712N. Go figure.

Make sure that your replacement motherboard has an 845GV chipset for best
results... Ben Myers