Power-up problems.
Discussion
On behalf of a friend of mine, I didn't have a clue about the problem so said I'd ask around.
She turns on her, the lights come on the front, but nothing happens. Which makes me think the PSU is ok-ish, but the power is only getting to the LEDs maybe and nothing else
Any ideas?
Cheers,
Graham
She turns on her, the lights come on the front, but nothing happens. Which makes me think the PSU is ok-ish, but the power is only getting to the LEDs maybe and nothing else
Any ideas?
Cheers,
Graham
OK, a few things it might be (I'm not trying to patronise you with these suggestions, they're common problems):
1. If there's nothing coming on the monitor, is the monitor definately plugged in/powered OK?
2. If the computer comes on and goes off (doesn't just come on and not do anything); is the Hard Drive coming on? You should hear a whirring and the red light on the front of the PC will come on/flicker.
3. If it just flickers on and off it may be the Power Supply, but may also be a short-circuit, this is unlikely if it's a big-brand PC, but possible if it's 'home-made' might be a wire shorting inside that's been triggered from moving the case.
Just check that everything's 100% plugged in correctly and securely and try to be more descriptive about what happens, exactly what sounds you can hear, what comes on the monitor, if anything?
AL
1. If there's nothing coming on the monitor, is the monitor definately plugged in/powered OK?
2. If the computer comes on and goes off (doesn't just come on and not do anything); is the Hard Drive coming on? You should hear a whirring and the red light on the front of the PC will come on/flicker.
3. If it just flickers on and off it may be the Power Supply, but may also be a short-circuit, this is unlikely if it's a big-brand PC, but possible if it's 'home-made' might be a wire shorting inside that's been triggered from moving the case.
Just check that everything's 100% plugged in correctly and securely and try to be more descriptive about what happens, exactly what sounds you can hear, what comes on the monitor, if anything?
AL
Just had a similar problem with my Mac (button lights up, but no start up chime, no fan, no attempt at start up). Did it by chance happen after a power cut?
The trick on the Mac is to reset the PMU (Power Management Unit), which you can look up on the Apple website. You may also have to replace the motherboard battery. Whilst searching, there also seemed to be a graphics card reset as well.
As already said, some power is getting through the transformer. Whilst obviously Macs and PCs are different, I suspect there's a similar trick for PCs. Check the manufacturers website.
The trick on the Mac is to reset the PMU (Power Management Unit), which you can look up on the Apple website. You may also have to replace the motherboard battery. Whilst searching, there also seemed to be a graphics card reset as well.
As already said, some power is getting through the transformer. Whilst obviously Macs and PCs are different, I suspect there's a similar trick for PCs. Check the manufacturers website.
Two things I've had experience of which may cause such symptoms...
1. PSU/power distribution reset. Not sure what the actual hardware is that causes this fault, but from time to time on newer PC's which retain a low voltage supply to the motherboard even when turned "off" (e.g. optical mice staying lit up when the PC is off) you can sometimes get them into a state where you have to completely kill and then restore the power-i.e. by turning off at the wall socket-before the base unit will power up successfully.
2. On 2 motherboards, I've seen leaky capacitors in the CPU power supply circuitry. Not leaky in the electrical sense, leaky in the "internal fluids oozing out of the case seals and forming colourful residue on the capacitor body" sense... On both motherboards, the resultant loss in power stability to the CPU was sufficient to prevent it running correctly. On the one board which was in my own system, this total failure was preceded by a period of several months when the system would require several attempts to start up, and when once started would then suffer from random crashes.
1. PSU/power distribution reset. Not sure what the actual hardware is that causes this fault, but from time to time on newer PC's which retain a low voltage supply to the motherboard even when turned "off" (e.g. optical mice staying lit up when the PC is off) you can sometimes get them into a state where you have to completely kill and then restore the power-i.e. by turning off at the wall socket-before the base unit will power up successfully.
2. On 2 motherboards, I've seen leaky capacitors in the CPU power supply circuitry. Not leaky in the electrical sense, leaky in the "internal fluids oozing out of the case seals and forming colourful residue on the capacitor body" sense... On both motherboards, the resultant loss in power stability to the CPU was sufficient to prevent it running correctly. On the one board which was in my own system, this total failure was preceded by a period of several months when the system would require several attempts to start up, and when once started would then suffer from random crashes.
AL666 said:No problemo regarding the patronising bit, I did exactly the same thing to her, it's best to check the obvious first
OK, a few things it might be (I'm not trying to patronise you with these suggestions, they're common problems):
1. If there's nothing coming on the monitor, is the monitor definately plugged in/powered OK?
2. If the computer comes on and goes off (doesn't just come on and not do anything); is the Hard Drive coming on? You should hear a whirring and the red light on the front of the PC will come on/flicker.
3. If it just flickers on and off it may be the Power Supply, but may also be a short-circuit, this is unlikely if it's a big-brand PC, but possible if it's 'home-made' might be a wire shorting inside that's been triggered from moving the case.
Just check that everything's 100% plugged in correctly and securely and try to be more descriptive about what happens, exactly what sounds you can hear, what comes on the monitor, if anything?
AL
I've asked her about any noises coming from the computer. She says the lights flash on the front but there is no noise at all.
Nothing comes on the monitor either.
Hirich said:It did indeed happen after a power cut. They've fixed it now, they had to unplug it and plug it back in
Just had a similar problem with my Mac (button lights up, but no start up chime, no fan, no attempt at start up). Did it by chance happen after a power cut?
The trick on the Mac is to reset the PMU (Power Management Unit), which you can look up on the Apple website. You may also have to replace the motherboard battery. Whilst searching, there also seemed to be a graphics card reset as well.
As already said, some power is getting through the transformer. Whilst obviously Macs and PCs are different, I suspect there's a similar trick for PCs. Check the manufacturers website.
Thanks everyone for your help, much appreciated
After all that they just had to "turn it off and on again"
:P
It really is amusing how often that works, my Mum rings me every few weeks saying that her PC's not working, so I tell her that (in my best IT crowd voice) and it always works!
ps. I know that switching it off and on again isn't technically what fixed the PC, but it's pretty similar :P
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