Fixed a dead laptop with a $4 part after the shop quoted the guy $280
A guy came in last Tuesday with a laptop that would not power on at all, and the big box shop near the mall had quoted him $280 for a motherboard replacement. I pulled the back cover, and right away I could see the DC jack was loose, wiggling around on a cracked solder joint. Ordered a replacement jack for $4 with shipping, waited two days, and had it swapped and running in about 40 minutes. Total ticket with labor came to $65, and the guy almost hugged me at the counter. There is no better feeling in this job than beating a big quote with a tiny fix. What is your best cheap part that saved an expensive job?