My old PC's ATX PSU died and I got a replacement in the form of a DELL 250W Power Supply model# HP-P2507FWP.
I plugged everything in, expecting my PC to come to life again, but while the green LED on the motherboard lights on as soon as I plug the power cord, nothing else happens when I press the ATX (momentary) power on button.
At first I thought that I ran into the infamous Dell proprietary (non-standard) ATX design, but when I compared the colors of the wires, they were all identical!
My next step is to actually measure voltages across the various pins to see whether indeed the colors match the documented voltage values but I still find it strange that I couldn't find any documentation or reference regarding the wiring of this particular PSU model.
More specifically, I have the following questions:
- Why do two websites that used to sell this PSU, claim it as having a 24-pin connector, not 20-pin? (one of the even has a photo of that 24-pin connector! and I can tell you with utmost certainty that mine has a 20-pin connector and the HP-P2507FWP original DELL label on it.
- Why is DELL's wiring's color coding identical to a standard ATX, despite the article describing even the colors being different?
- If my particular DELL PSU is standard... Are there additional plausible explanations for the fact that my PC won't respond to a power on signal?