Ticking Power Supply!?

[SoulAssassin]

A customer brings in a pc where their house had a severe lightning strike. Many electrical devices including the pc were damaged. The pc gets no power at all. I switch power supplies to test if that's the only problem but the new psu starts to tick!? Anyone know what thats all about? I have replaced many power supplies but never seen this.

 

[Nomarian]

I have seen this issue before. If they had some sort of electrical strike, then the motherboard and the power supply could both be fried. If you just replace the power supply, then a short on the motherboard can also damage the power supply and vice versa.

I would replace both the motherboard and power supply at the same time and see it that works for you. It has worked for me.

Norman

 

[edfair]

Maybe an ATX supply trying to bring up power to a damaged M/B? Or to a damaged processor? Ed Fair
unixstuff@juno.com
Any advice I give is my best judgement based on my interpretation of the facts you supply. Help increase my knowledge by providing some feedback, good or bad, on any advice I have given.

 

[SoulAssassin]

I kind of assumed the m/b was bad considering no beeps were given with the ram, vga, and any extra cards pulled. But I had never heard the ticking before, just curious I guess.

Thanks!

 

[sleew]

Maybe beeps died....? Sleew
Compaq & Microsoft TS
sleew@infosky.net

 

[DavidDCSA]

Many switching power supplies have what is commonly called a "crowbar circuit" which is used to protect the power supply from an overcurrent condition. When power is supplied, the output current is measured, and if excessive, the crowbar circuit switches the output voltages off, then on again for another sample of current. This frequently results in an audible "ticking" sound as the supply switches off and on.

 

[Guest_imported]

If it's an ATX PSU, disconnect from the motherboard but leave a "known to revolve" hard drive attached. Does the PSU still "tick" when mains power is applied? Now, in the motherboard power connector, short together the green wire (pin 14) to any black wire (say pin 13 or pin 15). If this powers up the hard drive, then the problem is more likely to be a fried motherboard. Be aware that there could still be problems in the original PSU - there are several different output voltages, and if just one of them is not functioning, the whole jolly caboodle is for the bin.

Good luck!


ROGER - GØAOZ.