A1466 820-00165 no display

[guruji]

Hello
I have a a1466 motherboard and the power rails seem to be fine
3.3v okay
5v okay
G3 hot 3.42v
Ram 1.2v okay
1.05v also okay
Cpu core 1.809v
Plt_rst 3.3v okay
I have flashed the bios and firmware but nothing also used a working donor smc
So my question is that once we get plt reset should the display come on

[mon2]

Re: A1466 820-00165 no display

1) you should be sleeping

2) any fan spin?

3) keyboard caps LED on? does it toggle?

4) What is the voltage of PPBUS_G3H ?

[reformatt]

Re: A1466 820-00165 no display

Usually I look at activity around U6100 to see if the BIOS is being loaded first (check clocks etc for activity). Current via Magsafe is a good indication of whether it's at least attempting to boot.

I've also had recently a board where the AUD_SPI_MOSI/AUD_SPI_MOSO/AUD_SPI_CLK pull ups (R1661/R1662/R1663) had corrosion on them. The main issue was R1663 had corroded and just fell off. Current for the board via Magsafe was about 0.3A and not varying.

I point this out since these lines go straight to the CPU, and obviously are interrogated during the boot process. So check all your data lines in/out of the CPU for any corrosion etc.

[guruji]

Re: A1466 820-00165 no display

1) you should be sleeping
yes thanks I know it was late to put a post but that is the only time i get to put it on board
2) any fan spin? yes it does spin but like 2 sec delay when power is pressed

3) keyboard caps LED on? does it toggle? no at all

4) What is the voltage of PPBUS_G3H ?

ppbus is 8.5V normal also battery is charging.

[guruji]

Re: A1466 820-00165 no display

some how i feel the activity on the bios is not right.The cpu is probably not reading the ME codes.