a-1502 led functioning

2informaticos

Administrator
Staff member
"EDP_PANEL_PWR_OR_PSR_EN --- 3v"
This requires at least LCD_PSR_EN, or EDP_PANEL_PWR to be present; both reported as missing by you.
Try to understand that we need accurate and consistent information.
If your measurment values change from post to post, difficult to help.
Remember to always check with internal LCD connected!

EDP_BKLT_PWM comes from PCH.
It is PWM signal, but you should get 2V DC approx, in working state.
No backlight possible with 0V; check diode mode to ground there.
Try doing PRAM reset 2-3 times.

Did you try known good compatible LCD assembly?
 
In my 820-3115 , S5_PWRGD is getting generated but PM_RSMRST_L is missing. Tracing the signal i find PM_SLP_SUS_L is missing. What should i check in PCH. ?
 

2informaticos

Administrator
Staff member
Please do not mix the boards.
If need help with 3115 board, open new thread.

What is the actual situation of A1502 machine?
 
i have given you exact reading of A 1502. Just now i have kept it aside. I will again take fresh complete reading of j8300 (all voltages) upto cpu. and let you know.
Just now i am working on 820-3115. Sus o/p signal from pch is missing. S5_PWRGD is getting generated but PM_RSMRST_L is missing. Tracing the signal i find PM_SLP_SUS_L is missing. What should i check in PCH. ?
 
i am doing my work but brother i am not happy with what i am doing. I have outline knowledge about the signals in apple motherboard. Pls help me if you have complete signals processing from first to last signals.
way back in my institute my teacher thought us about television circuit. I was knowining about it process , so confidently stage wise i used to chk the circuit. Rossman group is the best. I am totally alone here. If possible pls share your knowledge. I will be highly obliged
 
Top