This laptop has baffled quite a few people. Board number is 820-3437-B

Initial check-in was for fans running at full speed and the OS being sluggish. Pretty obviously pointed to an SMC error, SMC reset didn't help but AHT pulled up SMC errors. Reflowed the SMC chip with no luck, pulled up the board schematic and tested the power rails (PP3V42_G3H, PPBUS_G3H, etc) SMC_RESET_L is high so it's powering on, they seem fine. The Magsafe daughterboard carries an SMC signal so I tried swapping that and the flex that connects it to the board with known good donor parts, no luck on those...

Re: ASUS X200CA board power issues (schematic and datasheet attached)



Thanks for the reply, it does supply the correct voltage before shutting down. Grabbed that schematic from a different site but the guy posting it claimed it was close enough to the X200CA to ID what components are. One thing I did notice after posting this was the area with the IC was hotter than the rest of the board by a lot. I'm sure an IC that downsteps 19v to 3.3v is going to get toasty but it was enough to raise eyebrows. The client this is for ended up just telling us a few minutes ago...

Hey,

I've gotten fairly far into this diagnostic but I thought I'd get some input (no pun intended). We had an ASUS X200CA brought in not powering or showing any signs of life. No luck with power flush so I tore it apart to get the board. Found the motherboard schematic (ASUS doesn't like numbering their boards with anything besides the laptop model but they also seem to re-use boards in different models) and essentially just followed power all the way from the 19v DC jack to a step-down switch mode power supply IC chip.

Datasheet for the chip says it takes the input...

Re: New Members - please post your introductions here

Hey, I'm Brandon. Been doing IT for years now, recently started doing some more board level stuff. This site has been a huge help tracking down Schematics and tips. When I first found this place I sent an IM to my coworkers with a link and a few of them have lurked here too. Outside of my day job I perform music at night