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Reading a laptop schematic taught me something obvious I should have known | DIY Tech Fixes - nhfree.com

umam95•4mo ago

Reading a laptop schematic taught me something obvious I should have known

I was stuck on a Dell that wouldn't charge, battery was fine. Finally found a forum post explaining how to check the BQ chip with a multimeter by following the schematic. Turns out pin 6 had no voltage, 3 bucks for a replacement part later and it booted right up. Had been about to throw the whole board away before that. Anyone else gotten saved by reading a schematic when you usually just wing it?

3 comments

3 Comments

shane_wilson4mo ago

aint it just a bad solder joint or a blown cap half the time though? like yeah schematics help but 90% of laptop repairs are just visual inspection and swapping obvious dead parts. i've fixed a few dells by just flexing the board till it worked again.

fiona_lane4mo ago

Hear you out but gotta disagree a bit here man. Flexing a board might get you through a shift but that's just a bandaid, not a real fix. Visual inspection catches the obvious stuff like swollen caps or cracked solder but the tricky intermittent problems need schematics to trace where the voltage is dropping or what signal is getting lost. I've chased my tail for hours on boards that looked perfect until I found a busted resistor hiding under some flux or a cracked trace you can barely see. So yeah for the easy ones you're right but schematics save you when it's not the obvious dead part.

john_singh3mo ago

Gotta call you out a bit here @shane_wilson. Flexing a board to get it working is a hack, not a repair. You're probably just reconnecting a cracked solder ball temporarily, but that joint is gonna fail again. And while visual inspection catches a lot, it's not 90% of repairs. For power issues or no boot stuff, sure, but quirky problems like random shutdowns or usb ports that drop out? That's where schematics are the only way to find a damaged data line or a bad pull up resistor. You're not wrong about the obvious stuff being easy, but selling it like most repairs are that simple is setting new guys up for disappointment.