Hi

There is a notebook (LA-4221p) which is turning on and fan spins but there is no Display, I have checked the following.

Current Consumption is 0.8A
PLT_RST# -> 3.3v
H_RESET# -> 1.05v (CPU C1 Pin - Measured without CPU)
H_PWRGOOD -> 1.05v (CPU D6 Pin - Measured without CPU)
GMCH_ENVDD -> 0v (without LCD Connected)
+LCDVDD -> 0v (without LCD Connected)

After switching the motherboard on it doesn't read BIOS, there is clock available on BIOS chip (U17) but some strange signal present on SI SO pins.

any help will be appreciated, thanks.

You already tried to reprogram the bios?

yes I have reprogrammed the BIOS.

check that all coils are powered pl7, pl6, pl8, pl10, pl11 also measures that pu8 by pin 4 has 0.9v and pu11 pin 4 output 2.5v

Thanks for the answer.
PL6 is 1.1v
PL7 is 1.85v
PL8 is 1.56v
PL10 is 1.13v
PL11 is 1.13v
PU8 pin4 is 0.95
PU11 not soldered on the motherboard

friend here I leave the circuit to you to look at the voltages that you must have.
The GMCH_ENVDD -> 0v is wrong should be 3v
+ LCDVDD -> 0v this should be have 3v

try to measure with the LCD Connected

sorry for the mistake I made in circuit