Spent 4 hours chasing a phantom short on a laptop motherboard

Had a Dell Latitude come in that wouldn't power on at all. Found a short on the 3.3V rail, so I started pulling components. After checking every cap and chip for hours with my thermal camera and multimeter, the short was still there. Turns out the tiny metal shield for the WiFi card was bent and touching a capacitor leg right under it. I only saw it when I took the whole board out of the frame at a different angle. Straightened the shield with tweezers and it booted right up. Anyone else had a simple mechanical issue hide an electrical fault like that?

2 comments

2 Comments

willow_martin1mo ago

Yeah, that "tiny metal shield" thing is a classic. Read a forum post once where a guy spent a week on a desktop that wouldn't post, and it was just a loose standoff touching the back of the board.

the_julia1mo ago

That's an electrical fault causing a mechanical issue, actually.