Warning: Connecting PSU to empty motherboard is BAD

snutten · Post by **snutten** » Tue Nov 04, 2003 5:19 pm

I connected my two weeks old SS-400 to MB (ASUS A7N8X) while having no CPU or nothing mounted yet. Wanted to try if my new PSU fan was going to start up on the low initial voltage. Warranty void by modding and BANG there goes the PSU when I pushed start button on my case, the only thing connected yet.

There should be a warning about this. I sure as **** didn´t find any in either manual.

So now I warn all you nice fan-swappers at SPCR, just in case you didn´t know about this anymore than I did

breakspirit · Post by **breakspirit** » Tue Nov 04, 2003 10:18 pm

ive done that before and it didnt break anything. also, on another occasion, i tried that, but forgot to take out the cpu. the cpu didnt have a fan on it either...so the mobo started massively smoking and im all freaking out and then i saw the cpu looking melty. very cool, but i lost a few hundred bucks for that

Jan Kivar · Post by **Jan Kivar** » Wed Nov 05, 2003 10:35 am

I've started my old Slot-1 based computer without a CPU (ok, the CPU was there, but not pressed deep enough into the slot...

).

All fans and HD started, but no beeps/video... No damage though.

Cheers,

Jan

HadroLepton · Post by **HadroLepton** » Wed Nov 05, 2003 2:07 pm

before i learned of the green black wire trick i often used cpuless mobos to start an atx psu

i think it is rather your work on the psu which is to blame for your psu bang.

is the mobo still working?

energy · Post by **energy** » Wed Nov 05, 2003 3:44 pm

Nothing should happen when powered on. Perhaps a blob of solder or metal shaving was loose in the PSU after your mods and caused it to short out.

breakspirit · Post by **breakspirit** » Wed Nov 05, 2003 7:14 pm

HadroLepton wrote:before i learned of the green black wire trick i often used cpuless mobos to start an atx psu

i think it is rather your work on the psu which is to blame for your psu bang.

is the mobo still working?

green black wire trick?

SometimesWarrior · Post by **SometimesWarrior** » Thu Nov 06, 2003 2:37 am

breakspirit wrote:
HadroLepton wrote:before i learned of the green black wire trick i often used cpuless mobos to start an atx psu

i think it is rather your work on the psu which is to blame for your psu bang.

is the mobo still working?
green black wire trick?

Take a wire, or a bent paper clip, and put one end in the PSU connector hole going to the green wire. Put the other end in a black-wire hole. Plug in the PSU power cord, and it will start running. I've done this on 5 PSU's now, and it's always worked for me.

I'm not sure what happens if you connect the wrong wires, but it's best not to find out. Be careful!

HadroLepton · Post by **HadroLepton** » Thu Nov 06, 2003 12:06 pm

sometimeswarrior already said it all

here are some articles with nifty pictures
http://www.gideontech.com/guides/psu_powerup/
http://modtown.co.uk/mt/article2.php?id=psumod

also check this thread. about psus not running without load
http://forums.silentpcreview.com/viewtopic.php?t=5376

snutten · Post by **snutten** » Wed Nov 12, 2003 2:33 pm

I replaced the fan to a Papst, that´s all. Soldered well outside of the PSU, no chance of shortcut inflicting solder. I have no clue as to why the ****** PSU blew on me. The guy repairing it for me says the transistor (I may be confusing the electronics here, it´s the expensive central piece) is gone.
Heck, I don´t know.

energy · Post by **energy** » Wed Nov 12, 2003 7:29 pm

You probably mean transformer. Oh well.