There can be cases when you find out your laptop is not working at all. We have all gone through the same phase. This is called a Dead laptop condition. we can fix it by repair a dead laptop – displaymonk.
Here are some steps and tips to follow to repair your Dead laptop as a laptop chip level repairman or enthusiast.
Guide for repairing a dead laptop :
Below is the guide for repairing a dead laptop.
Check 18Volt current at current sensing resister
The current sensing resistor is the gateway from the laptop input battery section to go through all laptop components.
If you found that this section not working as usual then go for check-in for Volt in section MOSFET or Vin chip.
Check 3Volt at SIO VCC or EC BIOS pin no. 8
The next step for you to perform is checking 3volt at the SIO VCC pin or pin no. 8 of EC bios. Check if 3volt current coming or EC bios pin no.8 giving current using a multimeter.
A multimeter is an instrument to measure the current in the circuit. If it’s not working properly then go for checking always voltage section which is the 3.3v and 5v sections.
Check the power button in 3v to 0v variation
The power button in a laptop is the one that provides a gateway of current to the next circuits in the laptop. Check for variation in multimeter 3v to 0v. If it’s not showing the variation then mostly your power button is bad. You can replace it or repair it with a technician.
Check for RSMRST (resume reset) for 3volt and PM-PWRBTN
In laptop chip level repair it is very important to have reset signals to work. PM PWRBTN is the signal to check for and also resume reset signal RSMRST for 3v. IF it’s not happening check EC RTS for 3v and also checks the 32.7KHZ clock for working.
IF it’s not showing or running check for signals :
- THRMTRIP signal
- ACIN Signal
- LID SENSER signal.
If it is failing to do so then do flash the EC bios ( there are two kinds of bios ). If even if the problem persists then you can conclude that SIO is bad.
Check SLP_S3(SUSB) and SLP_S4(SUSC)
Check for SLP_S3 which is also called SUSB and SLP_S4 which is called the SUSC signal. IF they don’t found then go for the VCCDSW3.3 signal. If the VCCDSW3.3 signal not coming then check for why it not coming.
VCCDSW3.3 coming but not SPL_# and SPL_4 which are important signals for the laptop not coming. then go for checking the RTC RESET signal and clock of the RTC crystal.
the previous step not coming then do check for 32.7khz crystal. If RTC RESET and RTC clock is coming the check for DPWROK signal is coming. If the signal is coming then heat the motherboard by putting it into OVEN or BGA.
IF done all previous all things still SLP_S3 and SLP_S4 signal not coming then you can conclude that PCH is bad.
Check SUSP, SYSON, VR_ON signal
Check for SUSP, SYSOn, VR_ON signals. May all laptops not have all of these signals. Do check signals which are available.
If any of the signals are not coming then you can conclude that SIO is bad.
Check related PWD circuit and output voltage at the coil
If previous all steps are working and still the dead condition is not gone then check all the related PWM ( Pulse Width Modulator Chips). And also check for proper voltages at coils.
Have a look at chip level laptop motherboard repair small components also for having a good idea about the circuit. If all of the above steps working then the dead laptop problem must be removed.
You can also check our other laptop preparing help guides.
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