Ocelaris' PC power supply mod: easy version (with pictures) for ATX type

[Bitter]

I've had some PSU's that see a light bulb as a short and kick back off or won't even fully power up, usually the higher quality ones. Never tried a resistor, but I suspect the ones that don't like a bulb would also not like a resistor. There's probably a resistance threshold for what the PSU considers a short, I guess if you measured a 120mm fan and matched a resistor to that then it would work out.

[SteveYem]

11.8-11.9 should be close enough to 12V. It is possible that the PSU refuses to deliver the required amount of current for the ballast. Curious, the power rating table lists 3 different modes for 12V (including the -12V); perhaps it is running at that lower 0.3A? Some have reported that for their PSU, they have to apply load on the 5V line in order for the ballast to power up properly. An easy example is to run something like a tungsten turn signal bulb on the 5V line. Perhaps that might work for you? This is assuming it isn't limited to 0.3A.

I have at least one PSU which will absolutely NOT power on without something 'normal' connected to it. Be it a bare drive, a fan, or an old CD-ROM drive, it absolutely must have something connected to it besides a ballast or LED or other 'weird' thing.

On both of mine I wired in a 10ohm resistor so it starts up. Or else it powered the ballast for a second and shut off. Like stated above just hook up a turn signal bulb or something to the 5v line and try again

Thanks all for the advice. I connected a turn signal bulb to one of the +5V wires and it illuminated, but still no success with the ballast. Then I jumpered the ballast back to its power wires in the headlight housing and plugged the headlight into the car and still had no success. While the headlight was plugged into the car and the car was On, I measured the voltage at the wires going to the ballast and it was ~12V. So, now I'm thinking I might have a bad ballast.

[satrya]

Then I jumpered the ballast back to its power wires in the headlight housing and plugged the headlight into the car and still had no success. ... So, now I'm thinking I might have a bad ballast.

Or maybe one of the connectors may be slightly corroded?