I'm working on 820-3476 which came for no power. It had some slight corrosion on JTAG, around R7202, U7600, some on C3201 area and really small stain on U6100. I have removed JTAG, cleaned eveything, replaced damaged resistors, caps, resoldered chips (U6100 too). Computer turns on, works on battery and on the charger. Problem is, that SOMETIMES when I turn it off it will not turn on from power button. I have to reconnect battery, then it starts working again for some time. It olny happens when battery is conected. When on charger power button works every time. I have tried new keyboard, new battery and even replaced SMC with new one. Sadly there is no differenece... Diagnostisc shows no errors, when computer is on it works perfectly fine..
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820-3476 not turning on from power button unless reconnect battery
- Thread starter Narek
- Start date
You may have a problem with SMC_RESET_L level.
Clean and resolder all components in U5110 area.
Clean and resolder all components in U5110 area.
I have cleaned that area, replaced U5110. Still the same. After plugging battery SMC_RESET_L is 2,8V. This time when I plugged charger there was a chime but no image or backlight on the screen. I have measured SMC_LID: when lid is opened voltage is stable 2,6V, when cloesd it' jumping between 0,113V to 1,10V. After performing PRAM and SMC reset the image is back and SMC_LID voltage is 0,9-1,1V wneh lid closed. I have noticed, that if I perform SMC reset it always powers up with power button. Could be another bad SMC?
SMC_RESET_L is too low on 2.8V; is practically near its treshold point.
Check voltage on all U5110 pins.
Pay atention to R5127 and continuity to pin 3/U5110.
Check voltage on all U5110 pins.
Pay atention to R5127 and continuity to pin 3/U5110.
There is a problem with SMC_LID.
I hope you've measured it correctly.
Check R5250 and R5171.
Also inspect Hall sensor (J5250) for corrosion.
I hope you've measured it correctly.
Check R5250 and R5171.
Also inspect Hall sensor (J5250) for corrosion.
"I took off J5250"
Need to replace the Hall sensor, or machine will not go to sleep, when close the lid.
Need to replace the Hall sensor, or machine will not go to sleep, when close the lid.
