Lightning Strike.. Blown PSU?

A

asdf123

Limp Gawd
Joined
Jun 15, 2009
Messages
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Just recently we experienced a bad thunderstorm (NYC) and a very lound thunder strike caused my computer to just shut off along with the tv, connected to a power surge ofc. my machine now refuses to turn on, the green light on the motherboard stays solid but nothing powers up. no signs of any burn marks or blown capacitors on the board or any smell of burnt electronics. my tv turned out fine! :( I have a BFG EX-1000w psu which I don't find to be very reliable. I want to take apart the PSU and examine it but don't know what signs of damage to look for, any help?
 
Have you tried turning the psu switch off\unplugging it for a few minutes then switch it back on\plug it back in then trying to start your system? Or resetting your surge protector.
 
yes, left it disconnected for a half hour or so and the same problem occurs. also tried another outlet and no dice
 
This article was written in 1996 and is about AT and XT PSUs rather than ATX PSUs, but it's still useful:

http://www.soloelectronica.net/fuentes/Power Supply Repair.pdf

Then there's http://www.RepairFAQ.org , which covers about everything electronic, and it has a chapter specifically about power supplies (Search for SMPS -- Switching Mode Power Supplies).

Normally I wouldn't plug in a lightning-damaged PSU without first inspecting it internally for damage, especially shock hazards, but because the motherboard LED glowed, I'd plug the PSU into a grounded outlet (or at least a GFCI-protected one) and turn it on manually (connect the green wire on the big power connector to either black wire next to it) to check its output voltages. The glowing green LED proved you have voltage on the purple wire, but you need to measure the voltages at the red, yellow, and orange wires by using a multimeter. If none of those wires show voltage, there's a good chance the damage is in the high voltage section of the PSU, like the transistors on the large heatsinks near the big high voltage capacitor (one heatsink may be for power factor correction components, another heatsink for the inverter transistors). But if any of those wires show voltage, then most likely the damage is in the low voltage section, like the MOSFETs and diodes on the big heatsink closest to all the wires that go to the computer. See HardwareSecrets.com for many PSUs disected. Test components only while the AC power cord is unplugged.
 
Surely your UPS helped avert the damage.....

What's that you say? You don't have your expensive PC connected to and protected by an inexpensive UPS?
 
Zangmonkey said:
Surely your UPS helped avert the damage.....

What's that you say? You don't have your expensive PC connected to and protected by an inexpensive UPS?
Click to expand...
Some backup supplies offer no more protection than any cheap power strip containing nothing but 3 MOVs.
 
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