Member Avatar for mahearn

When I try to power on, the cd and dvd flicker but no power on. I then turn it off and wait a while, try several times and it turns on. Power supply?

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Short summary and context: reports the CD/DVD LEDs flash when the power switch is pressed but the system often fails to stay on; after waiting and retrying it sometimes boots. Several replies already flagged the PSU, front-panel wiring and component isolation (, , , , ). Those are sensible starting points; the remainder here expands on how that symptom maps to specific electrical faults and the most useful, targeted checks.

Why this pattern happens: the optical-drive LEDs can light as soon as the standby/main rails make an initial attempt to come up, yet the PSU may not reach a stable state or may refuse to assert the motherboard "power good" signal. Typical causes that produce an initial flicker then a shutdown are: failing electrolytic capacitors (reduced hold-up time), a PSU protection circuit that latches until the rear switch is toggled, a dead/weak 5VSB (standby) rail, intermittent short on the board or case wiring, or a faulty front-panel power switch. A bad RAM stick is less likely to cause only a brief LED flicker without any POST activity.

Practical diagnostic order (safe, low-cost first): observe whether any standby LED or keyboard light is present with the PSU main switch on (no standby = suspect 5VSB); measure the ATX standby rail and PWR_OK with a meter if available; isolate the case by briefly shorting the two power-header pins on the motherboard to rule out the front-panel switch; visually inspect motherboard and PSU for bulging/leaking caps or scorch marks; test with a known-good PSU or a PSU/load tester rather than relying solely on a paperclip fan-start. Note: a PSU that only restarts after toggling its rear switch often has an internal protection or capacitor failure.

A final note: a higher-wattage PSU (for example 500W) will not "overpower" a system as suggested by ; mismatched voltage selector (110/220) or a dead 5VSB can, however, mimic the reported behavior. Avoid opening the PSU—mains capacitors are dangerous—swap with a known-good unit or have a shop perform a loaded test for a definitive result.

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Member Avatar for RGPHNX

hI ,
Is mostlikely the PSU ..but.. before you run off & buy a new one.. do some basic troubleshooting first.
RGPHNX

Member Avatar for slackp11

I just re-powered my computer with a 500 watt supply and I'm having the same problem...someone said I might have over powered it?

Member Avatar for moderate_rock48

doubtfull that you overpowered it, is the fan on the PSU running?

Member Avatar for j198116

When I try to power on, the cd and dvd flicker but no power on. I then turn it off and wait a while, try several times and it turns on. Power supply?

Did you check the PSU connection to the Mother board, it can be loose sometimes this causes the computer to misbehave
OR
try checking the RAM to see if its tightly fitted into the slot

if all are okey then may be its a problem with the PSU itself, if you have a spare one try replacing and see if the problem continues.

j198116

Member Avatar for ceejeeb

Hey i have the same problem, my computer just randomly powers off and i cannot turn it back on without flipping the main PSU switch.

If you manage to fix it Mahearn let me know.

Member Avatar for sliepnir

Hey,
I know that it sounds really trivial, but check the power (voltage settings) in the back of your psu. I once heard someone had the 220 European set instead of the 110. Same thing was happening, fans powered up then went back dead...

Also, did you smell any burning smells? Maybe your cpu burnt out? Just a thought. Try taking out a single component and trying, ie your memory then next time try your hd, then try swapping vid card, etc.

Hope this helps,
Kevin

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