Member Avatar for c0llins05

Hi,

I built my pc round 3 months ago. Heres the system:

ASRock 775Dual-VSTA mobo
Pentium D 820 2.8 ghz
1gb DDRII RAM
ATI Radeon 1300 GFX card
MAXTOR 160gb HDD

The barebones were a handmedown from my brother in law. It has been running like a dream since I built it however the other day my girlfriend was running the vacuum round and bumped the base unit and it switched itself off..... I have disconnected everything and reconnected and still nothing. Thinking it may be a power supply problem I went out and bought a new one and still nothing. When I switched on nothing however when I unplugged it again I hear a small noise from the power supply as if its powering down but the power supplies fans dont come on. I baffled and currently sat here feeling like an amputee.....

Any help or suggestions would be greatly appreciated.

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Dani AI

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Good suggestion from to check the power switch — that is the quickest thing to confirm. Disconnect the two wires from the motherboard front-panel header and use a multimeter to verify the switch closes when pressed. If no meter is available, with the PSU plugged in you can momentarily short the two power-on pins on the front-panel header (brief contact only) to simulate the switch; if the system starts, the case switch or its wiring is the fault. Safety note: only short the two header pins and do this carefully.

If the switch is not the problem, isolate the PSU. With the PSU plugged in (but not started) measure the standby rail (5VSB) on the 20/24-pin connector. To force the PSU on for a bench test, short PS_ON (green) to any ground (black) on the same connector or use a PSU tester or known-good supply. If the PSU will not start or the fans never spin under that test, the PSU is likely faulty. If it starts when disconnected from the motherboard but immediately cuts out when connected, that points to a short or protection trip on the board.

Next do a minimal bench test outside the case: motherboard on an insulated surface, CPU + single RAM stick + PSU + speaker (or diagnostic LED). No drives, no extra cards. Inspect the board closely for bulging/leaking capacitors, scorch marks, bent LGA pins, or misplaced standoffs that could short the PCB. Make sure the 4-pin/8-pin CPU 12V connector is present and fully seated.

If those checks still give nothing, have a shop try the system with a known-good PSU and spare parts or pursue a board RMA. Before replacing anything, note any voltage readings, sounds (clicks), and which tests were tried — that speeds accurate diagnosis and avoids unnecessary parts swaps.

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Member Avatar for TT4Titans

When you you say bumped the base actually how hard was the bump.

open the case and make sure everything is seated good Ram,Video card cables everything.

Member Avatar for c0llins05

Not hard at all. Thats whats baffling. I have made sure everything is attached correctly took it apart nd put back together and still nothing.

Member Avatar for TT4Titans

Could be the power switch itself take a multimeter and put on the wires for the power button and have someone push the button and see if there is any continuity.I have seen this happen on a couple.

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