Ask Lemmy

I broke a display. More specifically, a shoddy Chinese NVR box broke the display's main scaler chip by sending a voltage spike down the HDMI cable as it was being plugged in. It wasn't an expensive display nor even mine (it was at the local hackerspace), but I was bummed out because it was one of the few good displays we had over there so I figured I'd see if I can fix it.

My knowledge of electronics isn't great, though I've seen enough Louis Rossmann videos to know the basic principles, so I spent some time troubleshooting it with, and I expect this'll get some flak given that this is Lemmy, the help of AI. I described the problem and what caused it to the AI, took some measurements off the board with its guidance and even figured out how to measure it with an oscilloscope to confirm the diagnosis. This way I could narrow the problem down to the main scaler chip -- by all accounts a pretty common problem with this brand of monitor, though this one hadn't failed so spectacularly.

I ordered a brand new chip from Aliexpress for a total of 15€. I did also find a full logic board on eBay, but it came to over 30€ with shipping and the photo showed it having red marker on top of the very chip I was looking to replace which made me suspect it could have failed QC or was torn out of a broken monitor, so I didn't want to risk it.

After a couple of weeks the chip arrived and it was time to try my hand at BGA soldering for the first time ever. I couldn't find a hot plate so I had to do the whole thing with just the hot air station making it harder than it should have been. I managed to tear off three pads taking the old chip off somehow and had to very carefully fix those with some fine copper wire carefully manipulated with tweezers and a crafts knife under the microscope. Against all odds after I got the new chip soldered in, the display worked perfectly on the first try. The success felt pretty ecstatic.