my power supply is not coming on
typing this from a very old mac power book

my Q6600's power supply is not turning on
it is a rosewill RP550-2

the computer was not outputting a video signal at start up sometimes
multi restarts were needed to get it to have a signal
and the front power button was not working [needed to use the rear switch on the P/S]
yesterday it refused to do anything no lite no fans ect

does the power supply need a input from the M/B to turn on ?
does the front power button make a contact [can it shorted? ] ?
any way to test the P/S or get it to turn on if not hooked up to the M/B or front start button ?

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Question wonder and be wierd
are you kind?

jump the green wire and any black wire and it will "power on"


edit: unplug all cables from the motherboard, and add-on decives for safety, jump the green wire and a black wire to the main connector to the MB, and it will power on.

the front button connects to the mainboard, and the mainboard controlls the powersupply.

[This message has been edited by hookdonspeed (edited 03-10-2013).]

~15 bucks will get you a tester, that tests all signals, under load.

http://www.superbiiz.com/de...ak87UCFahDMgod_lcAbQ

I have one of them. Got it from tiger if i remember right.


EDIT: Back in the old days when i was still doing desktop support, id have a known good PS in the trunk of the car.. clumsy, but quicker and more reliable than a meter without a 'real' load. ( before testers were available )

[This message has been edited by User00013170 (edited 03-10-2013).]

at minimum...
3 + & 2 - volts to test.
Some wires are signal to turn PSU fan, sleep mode, PSU Temp, etc...
Put 12v on Signal etc and fry the unit.
Example see http://www.helpwithpcs.com/...sics-inc-pinouts.htm

quote Originally posted by hookdonspeed: jump the green wire and any black wire and it will "power on"

not all... Some designs won't power up w/o loading it.

quote Originally posted by User00013170: ~15 bucks will get you a tester, that tests all signals, under load...

TD/CompUSA stores usually has testers in stock.

Using a tester means Much less risk on shorting etc and blowing a good PSU.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave (It's also at the top and bottom of every forum page...)

[This message has been edited by theogre (edited 03-10-2013).]

quote Originally posted by hookdonspeed: unplug all cables from the motherboard, and add-on decives for safety, jump the green wire and a black wire to the main connector to the MB, and it will power on.

As theogre has stated, some (most?) switching power supplies require a minimum load to operate. The minimum operating load is now commonly listed in a power supply's specifications, but if you don't know for sure you should assume that a minimum load of 10% to 15% of the maximum rating is required.

I will mention that the last high-end ATX/EPS12V power supply I bought (Antec TP-550) was rated for proper operation with zero load on each rail. This may be a trend in newer and more expensive power supplies.

[This message has been edited by Marvin McInnis (edited 03-11-2013).]