Sharp QA-2500 AT Power Supply Trouble

[kd5crs]

Hey everyone.

I'm trying to power my QA-2500 with an AT Power supply. I searched the forum, but I didn't see anyone else running into this issue (which leads me to believe I'm doing something dumb).

If I connect nothing to the AT supply and hit the power switch, the power supply fan starts up.

If I connect a computer case fan to the power supply using a 4-pin connector and hit the power switch, the case fan and the power supply fan start up.

If I stick the 5v, 12v, and dual grounds from the power supply into the proper places on the QA-2500 and hit the power switch, the power supply fan does NOT start up. Neither does the QA-2500 panel, nor the case fan.

If I then remove the wires from the panel and cycle the power switch, the power supply and case fans start spinning.

Is this evidence of a short? Of a bad panel? Am I missing something basic?

Any help would be appreciated.

Thanks.

 

[kd5crs]

Anyone know? Do I have a dud panel? I have not had much luck with my troubleshooting.

 

[bekim321]

It might be that your power supply doesn't have enough current output to supply to your lcd hence it doesn't power up with the lcd plugged in, or the other reason is that you wired the lcd backwards.

 

[valveman]

PC power supplies require a small load on the 5V line in order to run. Get a 5 ohm 10-20W power resistor and connect it to the 5V line. This will cause the power supply to start. Without the load on the 5V line, your powersupply will not regulate and produce voltage.

Robert