help PC trouble
 

Lads pc has packed up but still has led lit on the board, was thinking it was the power supply its a kt133 board any ideas .

Fan not turning so help appreciated

Re: help PC trouble
 

p'raps the fan's died...

...causing the CPU to overheat and the board to shut down to protect it

Re: help PC trouble
 

good idea worth trying gets spare fan

Re: help PC trouble
 

did not work led is lit on the board

Re: help PC trouble
 

have you seen

this?

Re: help PC trouble
 

Fans use the 12V supply and I would guess that the LED is powered from 5V. It is possible that the 12V has failed but the 5V has not. Locate a spare disk drive connector and stuff your voltmeter in there. The two black wires in the middle are 0V, the red wire is +5V and the yellow is +12V. If you see one supply but not the other then the PSU is probably stuffed.

Re: help PC trouble
 

I would check the power supply as well. Have had exactly same symtops here (mb led lit but no other 'action' from the board. Change power supply and all was ok again.

Good luck

Re: help PC trouble
 

It would laso be worth re-seating the cards and ram. Loose components can stop the board posting.

Re: help PC trouble
 

hmm....

my other system did this when the cpu was fried.... is the internal speaker connected? does it beep when you turn on?

could be one of many things causing it.

Re: help PC trouble
 

I would guess at the PSU, my mothers blows about every 9 months (god knows what shes doing!) and her light stays on on the motherboard. Go spend £20 (MAX) on a new PSU and get installing (some dealers will let you take em back if it wasn't that).

Re: help PC trouble
 

£20 max! No wonder they only last 9 months.

When designing a power supply, it is common to put in something called a crowbar to protect the outputs. This simple circuit measures the output voltage and if, for any reason, it gets too high it tries to short-circuit the output. Of course, if you're designing down to a price then you forget about the crowbar. Which is fine until the day you get a spike down the mains, the output jumps and then takes out some of the electronics. This happened to my brother and it permanently zapped his hard disk drive :shocked:

I would never skimp on the PSU.

Re: help PC trouble
 

Have to agree. False economy imo. CHeap / poor powers supply can cause all sorts of problems and can even damage other components. Not an area I wouls skimp on myslef.

Re: help PC trouble
 

Right New PSU on order tobe delivered saturday had a hunch it might be psu and dvm confirmed it bwill let you all know lateston saturday.

I appreciate all the help

BTW lad on P166 pc :D that will teach him :angel: