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HP Pavillon A6437C desktop issue

This computer has no video,keyboard,sound or mouse functions. SATA Hatachi Travelstar 500 gb hdd spins up,ethernet lite is lit,psu & power button are lit as well. dvd/rw drive opens & closes at my command. CPU HSF spins up fast for a second then slows down a bit but continues to spin at a slow rate like it a normal function. Tried resetting bios by removing the cmos batt & moving jumper. Thinking of purchasing a pci 4 digit readout diognotic post card & installing it in the pci slot. Took the hdd out * installed it in my running pc & it recoginizes it. Has Windows Vista Home Premium 64 bit installed. What other testing do i need to perform? Also was planning on purchasing a programmed bios chip & installing it to see if it might be a bios failure issue. Any ideas would be greatful. Thanks! David

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Check into...

In reply to: HP Pavillon A6437C desktop issue

Looks like the mtrbd. is shot, though with no video it could be a video problem. Are there any beeps, during boot-up? You don't need any HD/CD drives attached, try to boot, results? Swap ram around or try known good ones. Any burnt smells, cabling OK, beeps? Did you return bios jumper to proper setting as to not "clear setting". Have you tried a another video card. What was the system before this problem cropped-up? Any recent install or action before this happened. Any power surges, lightening strikes, hot room, etc.?

You can remove the system mtrbd..etc. to a cardboard on table, attach a minimum system and try boot-up and/or retry above actions.

tada -----Willy Happy

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HP A6437C issue

In reply to: Check into...

Well Willy, I was planning on making this post quite short but looks like I need to add some more info.I purchased this HP from EBay & the listing said the video was not posting. He failed to add the mouse,keyboard,sound & video did not respond. The video graphics card is emedded into the board (Foxconn) & has no pcmi graphics card installed. The only card thats installed is the modem card& I removed it as well. I really did not care cause it is a really fine machine. For the testing everything & did everything there was to try to isolate the problem from removing the cpu & mobo from the chassis to inspect for burned marks & such. Tried removing hdd,disconnecting the dvd/rw drive plugs,card reader & anything else related to plug & play devices one by one. Haven't tried removing the mobo & setting it on cardboard & testing it that way though. I was going to wait till I purchased the post digital card & testing that way. I first started by installing a new psu which I assumed the original one was ok cause all lites were lit on the psu & power button & The dvd/rw drive would open & close. Also tried adding the memory one by one. Now I could have a problem with both memory modules, but how often do you see that happening in your lifetime? Very rare! It has to be either the cpu mobo or the bios causing the problem I would assume. Money is scarse around here to just start popping hardware in. Thats why I thought the digital diag. card would be my next approach. I'm desperate to try anything before committing the mobo all together. I have been messing with this HP for about 3 weeks now. Tried to reflash the bios from HP support links downloads but did not quite know how to burn it to a cd to boot to the HP. I am going to spend the $20.00 for the bios programmable chip first along with the tester board. How dependible are those cheap psu testers? I have one & the only lite that does not lite when testing is the -5 volt. All others lite up & stay lit. I thought maybe the psu had a short so I installed the new 400 watt psu & still the same thing. So thats where I am now. Contacted HP support & they even agreed this was a strange thing happening they had never seen before & they were glad to send me a package to ship it back. Yeh!! Right!! I know how deep they want to reach into your pocket. I have all the time in the world to try to figure the HP out but I am getting very impatient up to now. I've been to many support sites & agree like you do that the mobo may be the problem. Thanks for your response back.

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More troubleshooting....

In reply to: HP A6437C issue

With all the problems you have and knowing it came from eBay, now you know why it was sold. At least they were honest and explained the issues it had. NOW in no way even try to bios update this unless you can swap the bios chip out itself. If you can't see any video its not going to allow you proceed in a proper manner. Because you have no video and its integrated is your issue. This alone makes the mtrbd. useless as it locked into a mode of not passing by the int. video port. If you can place another video card and see if any display becomes available. Using a diag. card should at least point to a video problem if anything, however I find no use for them myself. As for -5V, its not used in modern PC at least directly.

As for the HP response, that maybe correct though it should cost you at least a mtrbd. replacement if not under warranty. Basically, all HP would have done is replace the mtrbd. and check it out, etc. then return. They don't fix anything, but replace. If they want to find out the real problem is they pass it on to see if its a manufacturing issue.

I see no quick resolve unless you get your hands on another same HP system to rob parts. Use a magnifying glass to look over mtrbd. components, check for bad caps as well, google for examples.

tada -----Willy Happy

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Just a thought...

In reply to: HP Pavillon A6437C desktop issue

..since you said: "I purchased this HP from EBay & the listing said the video was not posting"

Have you tried it w/ a different graphics card? (that mobo has a PCIe x16 slot available (maybe the one from your running PC works))
->If it works w/ a discreet gfx card, get one - I've seen decent ones @ <$30 [ comes to mind)

Also, if there's no video, one really can't tell if the keyboard and mouse work or not.


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HP Pavilion issue

In reply to: Just a thought...

I appreciate your response, but I can not see why a graphics card would have any effect on the mouse,sound,& keyboard problem as well. I could give it a try though. I can not hear any beeps from the onboard speaker. The monitor goes into the power save mode. Tried a differant mouse,keyboard & monitor. Havn't tried my lcd monitor, just the crt monitor.

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HP Pavilion issue

In reply to: Just a thought...

Well! the last owner of this HP was not the original owner. He just sells used pc's & does not bother with trying to diag. their problems. He made that comment on the listing on EBay. I Have the mobo out of the chassis as we speak & going to attach hardware one by one & see what happens. Already took the cpu out & cleaned the contacts Along with cleaning the ram contacts as well. Can not see any bad capcitors or any bad places on the circuitry on the board. This is a 2008 HP & looks very clean. Thanks for hanging in there everyone. If I get this HP up & running, I will definately respond back with the fix so it might help someone else in the future with this concern. LOL! My head is almost completely bald trying to figure it out.

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HP Pavilion issue

In reply to: HP Pavilion issue

Well! I just got through removing the board from the chassis & reinstalled it back after plugging in the monitor alone & no post. Installed memory one by one & no post or beeps. I am now completely bald LOL!!! Threw away by brush. No Longer need it.LOL! Just a little humor to keep me sane. I'm going to try the digital diag. card once I purchase it & try that & see what happens. Hope those testing cards work the way they say they do. I believe & this is my theory, the cpu has gone south. Like it's shorted. The reason I think it has is because when I power up the system, the keyboard nums,caps & scroll lock lights flash on for a split second & then go out. That looks like an internal short somewhere on the board. I've drawn my last straw for now.

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Did you...

In reply to: HP Pavilion issue

...try it w/ an actual gfx card or just the integrated one?

I've fixed several Integrated Component failures (audio/video/lan) by installing a known working card (from my "junk cabinet").
e.g.1 my HTPCs audio quit->fix: dropped in an old soundblaster
e.g.2 Mom called having salvaged a Compaq d330 from her company's junkpile (failed LAN and failing video)->fix: added a LAN card and an ancient Radeon 9200 AGP.

The point: Try it, You might be surprised (unless the mobo is dead)


PS. hold on to that brush for a while longer - The Lion's Mane might make a comeback Wink

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Testing continued

In reply to: Did you...

Well! I tried another video card from one of my other pc's laying around & it didn't help a thing. Does it possibly mean the mobo is gone or the cpu. Were grasping straws now. Hope I grab a long one.

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Looks grim

In reply to: Testing continued

The cpu might be fried which can also be tested w/ a known working one (assuming you have a compatible cpu / are willing to buy one for testing)

You did mention getting a diagnostic card... I'd wait for that (if you don't feel like switching the cpu at this point)


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A6437C motherboardconcern

In reply to: Looks grim

Well! I bought the pci card & found out the pci slot is not dead cause the card posted some codes but not that familiar with the codes. Did a Google search for explainations of codes for my motherboard & it all so confusing trying to decifer the codes. The only thing that is not normal is the power indicator led lites all lite up except the -5 volt lite & the reset lite flickers for a split second like it should & the site says the -5 volt lite should be lit & if not then there has to be a direct short to the mobo. This mobo screws directly to the chassis & has no standoffs. What do I know!! Putting this aside & purchase a cpu & if that has no affect then I guess i'll get a mobo. I will not give up yet. Thanks for your recent reply. David

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A6437C motherboard concern

In reply to: A6437C motherboardconcern

One more note.I mentioned on my earlier post where the cpu would spin up fast then slow down a bit. When I unplug the 4 pin cpu power connector & then power it up it makes the cpu fan spin up fast & stays that way until I shut it down. Thats telling me the cpu may be shorted. There again, what do I know. When it comes to this type of concern I am not a computer savy but i'm learning oh! so fast.

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How about a link?

In reply to: HP Pavillon A6437C desktop issue

(to those diagnostic results)

1) -5V is obsolete => current PSU's don't output -5V (as Willy stated earlier in fewer words)
2) Unplugging 4-pin CPU pwr: the BIOS controls the CPU fan according to temps from the CPU thermal sensor (no power=no feedback to BIOS=fan at full speed)... and that means the mobo might be OK
Hence a cheap CPU may be a cure (e.g.


PS. if it turns out to be the mobo, I hope you have an OS disk to work with.

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In reply to: How about a link?

Well! I'll give the cheap CPU a shot but i'll have to puchase a recovery Vista Home Premium 64 bit from a site I saved just in case. Does the 64 bit makes any differance? Does it matter what bit is 64 or 32? It has a SATA Hatachi Travelstar 500 gb hdd installed. Thanks!

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CPU question

In reply to: CPU ?

Hey H-bound, what would happen when I get the intel single core(even though my system takes a dual core cpu) when I drop it in w/out loading the recovery cd. Will it post to at least tell me the system is up and & running? Do I need to update the bios also? Should it at least be a dual core intel cpu? Kinda new at this type of testing for mobo's & cpu's.

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re: CPU question

In reply to: CPU question

1)If all parts are in working order (mobo, cpu, video & ram), the system will post and give a boot error message (different msg w/ most mobos) ->no cd's or harddrives are needed for P.O.S.T. (PowerOnSelfTest)

2)a BIOS update isn't necessary since that Celeron 430 is supported (Celeron 4xx series (Conroe core) up to Celeron 450) Mobo specs from HP

3)If the CPU is on the mobo's "supported CPU's list" it doesn't matter if it's a single- or dual-core

4)32-bit/64-bit: doesn't really matter since that HP is 64-bit compatible (hardware)... currently the only advantage of 64-bit for home users is the ability to use more RAM (>3GB). Most 32-bit software will raun in a 64-bit OS.

T @GMT+2(PST+10)

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cpu is my next step

In reply to: re: CPU question

Thanks for that info H-bound. I'll purchase the Intel Celeron single core since its the cheapest to see if it will work.

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cpu on the way

In reply to: cpu is my next step

Bought a celeron & its on its way. Hope thats all it is. Have a exact specs mobo watching on Ebay & I was lucky to find an exact mobo. That way I don't have to reload with a restore cd. I looked at the files on the hdd & it had no personal files. Just windows. Wish me luck. I have read alot about mobo & cpu troubleshooting concerns & this one is the only one that baffles me. Some of the other computer forum sites say the same thing.

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In reply to: cpu on the way

Well! I installed the Celeron cpu & still did not fix the concern. Then I purchased a programmed 8 leg bios chip from an EBay seller which was a new one & it also did not help things. I guess i'm down to something shorted on the mobo. I read on a site about the hsf spinning up fast & then slowing & came up with something to do with a thermal shutdown issue possibly. Can't access the cpu temps for the problem with no video,mouse or keyboard functions. I did notice my usb ports are not functioning as well. Thought about taking the fan out & plugging it in to another mobo I have lying around & see if the Asus fan is binding or something to that effect. The cpu thermal swithing device on the mobo which I don't know where that is may have some affect on it protecting the cpu from overheating & slows the fan down. Still trying to decifer the codes on the pci diag. card as well. The 4 digit readout starts flickering rapidly on bootup. Oh well! On to more testing before I committ to purchasing another mobo. Its wearing me down to a frazzel.Thanks for you guy's hanging in there.

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New mobo on the way

In reply to: Update

Well! I found an exact twin mobo & its on its way. It is a a fairly new board, (6 months old). It came from a HP A6600F HP slimline desktop.

The only differance in the 2 boards is the one i'm installing came with a 300gb SATA hdd & my A6437C slimline desktop came with a 500gb SATA hdd.

My question is, when I install the new mobo, will I have to reset the bios jumper pin ( or remove the batt.) so the system will recognise the new hdd or just simply install & power it up?

I'll have to reinstall all the hardware from my mobo to it. CPU,memory,hdd,etc.

This what the EBay seller posted:
I bought this because I was going to upgrade my RAM but then found out that even though my old board only supports 2gb RAM, it will run with 4gb. So I am selling this motherboard since I no longer need it. The board was tested working and is only 6 months old according to who I bought it from. I will ship UPS since this is an expensive item, and UPS has insurance included. If you have any questions please let me know. This board come from an HP a6600f.

Will I have any suprises in doing this?
Thanks! David

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Sorry about the late reply..

In reply to: New mobo on the way

(been on vacation & moved)
ok here goes... If indeed the new mobo is an identical twin, no problems should arise (h/w drivers etc.) However, one should allways be prepared for the odd surprise or two when dealing w/ a M$ OS Wink .

T @GMT+2

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Final conclusion

In reply to: Sorry about the late reply..

I decided to take them to the Indian VoTech center & let them have some fun testing it.
I'm a member or the Indian VoTech center.
Would be some intresting testing on it for those young kids as long as they don't screw it up.
Only cost me $5.00 to have it tested.
Pretty sure it's the mobo at fault.
They merely test it for any faults & report back & I decide if I want them to fix it & I pay for the parts.
I most likely will reapir it myself.

Just got a response back yesterday from the Vo-Tech center & they agree also the motherboard was indeed bad.
I had already suspected the mobo for being bad but thought it would be a good for the students to learn more about them.
I dought they could tell me whats up with the board & what componants are bad.
Capacitors I am told are the #1 componants that go out on mobo's.
I just wished I new what internal componants resistors,capacitors,relays,switches,regulators or what ever was was bad on it so I can learn to repair these boards.
Thats what my goal is.
To learn more about them & go into the business repairing them.
Did a search for motherboard repairs & comes up with companies that repair them

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