Had a Dell Optiplex power supply go bad in a weird way yesterday

Client brought in a 7020 that wouldn't boot. No lights, no fan spin. Checked the wall outlet, fine. Swapped the power cord, nothing. Pulled the PSU and did the paperclip test. The fan spun right up. Put it back in the case, dead again. Turns out the 24-pin connector had a cracked solder joint inside that only failed under load. Ever seen a PSU pass the test but fail in the system?

3 comments

3 Comments

miam753d ago

Oh man, @jana_fox50 is totally right! I had the same exact thing happen with a bad motherboard pulling everything down. The paperclip test tricked me too, but swapping in a known-good board brought the whole system right back to life.

lane.cameron18h ago

Yeah but @jana_fox50, a paperclip test doesn't load it like a real system.

jana_fox503d ago

Wait, are you sure it wasn't just a bad motherboard? That sounds way more likely than some magic hidden PSU fault. The paperclip test proves it can deliver power, full stop. If it works outside the case but not inside, you've got a short somewhere else, probably on the board itself. I've seen that a dozen times, a bad cap or something pulls too much current and shuts everything down. You gotta check the motherboard before blaming a PSU that tested fine.