Member Avatar for mtplewis

I recently removed and reseated the CPU in my HP pavilion a1600n, and it will not display anything when powered on. There was one low short beep when powered on. I reset the CMOS jumper, Removed and reseated the CMOS battery, Removed and reseated the RAM, and removed and reseated my pci network card. Now when i plug in the computer it automatically starts up and the fans are blasting incredibly fast.

Any suggestions?

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Dani AI

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Short version: the symptoms (automatic power‑on when AC is plugged in, fans at full speed, and no video) point to two separate fault domains — power/control (PSU, front‑panel wiring, BIOS “AC power restore”) and POST/video (motherboard, CPU, RAM, GPU or speaker). and raised thermal‑paste and bent‑pin possibilities; those matter, but the following focused checks will help isolate which subsystem is failing before you replace parts.

Safe, prioritized troubleshooting (take ESD/mains precautions: unplug before touching connectors):

  1. Front‑panel / PS_ON isolation — unplug the case power switch header from the motherboard, then plug AC back in. If the box still powers on immediately, the problem is not the case switch. If it stays off, the case switch or its wiring is suspect.
  2. PSU behaviour — with the system disconnected from the board, test the PSU with a proper PSU tester or a known‑good spare (paperclip tests are less reliable). Look for correct 5VSB and stable rails. If the PSU spins full blast on plug‑in, it may be defective or receiving a stuck PS_ON signal.
  3. BIOS AC‑restore setting — once you can get video, check the BIOS option often called “Restore on AC Power Loss” and set it to “Power Off” (clearing CMOS can change this default). That fixes automatic start when AC is applied.
  4. Breadboard minimal system — outside the case, connect only motherboard + CPU + correct 4/8‑pin CPU power cable + one known‑good stick of RAM + PSU + monitor (and speaker if available). This rules out shorts from case standoffs, bad cables, or other cards.

Video/POST checks:

  • Confirm the 4/8‑pin CPU power is present (many forget this).
  • Try a different monitor and cable and test the monitor on another machine.
  • If you hear a single short beep, note that beep codes vary by BIOS — consult the board/HP manual for exact meaning; absence of POST with no display after the breadboard test usually points to motherboard or CPU.

If after the above the board still auto‑starts or shows no POST, swap in a known‑good PSU and RAM if available; if that fails, the motherboard or CPU is likely at fault and professional diagnosis or replacement is the next step.

Recommended Answers

All 12 Replies

Member Avatar for The New Normal

Sounds like you're on the right track. Perhaps check all your power plugs are seated firmly and the right way around.

Did you remove and put on a new layer of 'goop' on the CPU? Apparently if you take off your CPU you need to replace the 'goop' otherwise it doesn't make good contact (an amazingly thin layer of the stuff is advised). Poor contact makes for more heat and therefore fans blasting incredibly fast.

Member Avatar for jermaghs07

you may have bent a pin. i would pull you CPU again and see if one of the pins is bent. if so take a very small screw driver or something and try to bend it back. just be very careful not to bend any of the other pins. and you do need to re-aply the thermal goo after you remove the heat sync. also make sure none of the goo got in the pins because the goo has a metal substance in it and can short out the CPU if it got on the pins.

For future reference if you aren't replacing the CPU don't take it out. it doesn't ever need to be cleaned or re-set. just leave it in.

Member Avatar for your uptime

u mnust install new window..ure pro will be sort out

Member Avatar for your uptime

and one more thing dont use the pirated window...it will definitely disturbe u again

Member Avatar for jermaghs07

u mnust install new window..ure pro will be sort out
and one more thing dont use the pirated window...it will definitely disturbe u again

Is this guy speaking english????

I didn't understand any of that!

Member Avatar for The New Normal

Either it's

your pirated XP/Vista caused the problem, get a professional to re-install a paid for version

or

install a window in your house, pay for a pro for the night and make sure your new glass is not from the Caribbean.

Either way I don't think that's the problem.

commented: your funny +1
Member Avatar for jermaghs07

Either it's

your pirated XP/Vista caused the problem, get a professional to re-install a paid for version

or

install a window in your house, pay for a pro for the night and make sure your new glass is not from the Caribbean.

Either way I don't think that's the problem.

LOL :icon_biggrin: :icon_mrgreen: :icon_biggrin:

Raj is right that's not the problem.
just out of curiosity... are you running a pirated copy of Windows? don't worry i won't tell anyone!

Member Avatar for Member #380444

Are you retarded? How the hell is he supposed to install windows if his computer won't start? Jackass. More likely is that his antivirus is installed incorrectly.

Member Avatar for noel815

I recently removed and reseated the CPU in my HP pavilion a1600n, and it will not display anything when powered on. There was one low short beep when powered on. I reset the CMOS jumper, Removed and reseated the CMOS battery, Removed and reseated the RAM, and removed and reseated my pci network card. Now when i plug in the computer it automatically starts up and the fans are blasting incredibly fast.

Any suggestions?

If still not working that you removed already everything try to clean the edge of the RAm use eraser clean both sides and if still the beep sound come up the memory slot is damage.

Member Avatar for jermaghs07

who exactly are you calling retarded????:angry:

we where making fun of the guy that doesn't speak English.
I was just asking out of curiosity if he was using pirated windows

Member Avatar for abhisdm

The problem might be tht the RAM/video card is not placed back correctly.. try to keep you CPU clean.... check by swappin the RAM slots...

Member Avatar for Member #380444

Sorry, I was referring to your uptime not jermaghs07 or any others. I only posted for fun and obviously haven't checked for months. If you think windows has anything to do with a computer powering on you might be retarded too. If you don't then you have nothing to worry about.

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