I welcome all good people in this forum 
I have a problem with repairing Lenovo motherboards. W540 LKM-1 WS MB 12291
I have 4 pieces of W540 motherboard - they all have the same symptom.
- motherboard is switched on for a moment but the screen is black.
- if the battery is inserted, the plate switches on for a moment but the logo appears on the screen
- Consumption 2A
I was programming different bios, I was cleaning the region
DC and BAT input transistors - good
I do not have a schematic for this model, maybe you have a similar one?
Is it necessary to program the MEC ?? by programming a new bios? Is this connected to each other in the
same way as BIOS and EC?
I am asking for directions what else to check
I have a problem with repairing Lenovo motherboards. W540 LKM-1 WS MB 12291
I have 4 pieces of W540 motherboard - they all have the same symptom.
- motherboard is switched on for a moment but the screen is black.
- if the battery is inserted, the plate switches on for a moment but the logo appears on the screen
- Consumption 2A
I was programming different bios, I was cleaning the region
DC and BAT input transistors - good
I do not have a schematic for this model, maybe you have a similar one?
Is it necessary to program the MEC ?? by programming a new bios? Is this connected to each other in the
same way as BIOS and EC?
I am asking for directions what else to check
