ANOTHER LENOVO B50 30 - BUT NOT SO EASY THIS TIME (Part 1)

I found another Lenovo B50 30 amongst the batch of 14 that I purchased two weeks ago, so in this video I try to work out what is wrong with it. Please like and subscribe and leave comments and suggestions below.

[@toannguyen-hf5xk]

Thank teacher

[@danarepouille1381]

Sure seems like an EC problem. I wish I could see the data sheet for the NUVOTON EC chip, which shows what pins 1-5 are for, since they had corrosion on them.
I don't remember you saying that you tried removing the coin cell battery to force a BIOS reset. I also don't remember you saying that you tested that broken inductor for continuity. You did say it was working fine, though. I hope you can find the fault.

[@Kareem-Ahmed]

What about changing the RAM modules with some DIMM you know it works? Also, other parts may be responsible for short circuits, basically any component that's attached like the CMOS battery, and I hope it's not the GPU or the CPU!

[@valinkakomputer]

if all power source (3,3v, 5v, main volt) is okey and bios is fine and if ram is fine, from my experience is IO chip, but IO chip is responding to power btn, it might be half shorted, you can check all the pins based on IO chip schematic

[@valinkakomputer]

the worst thing if it has PCH chip, that chip must be the problem and costly to replace

[@therepairshare673]

@@valinkakomputer Hi Valinka, thanks for your helpful comment..... "but IO chip is responding to power btn" - This is my thinking also. It seems that the IO is responding correctly to the button press and all the main voltage rails are coming online, so the IO is certainly at least partially working. So I'm thinking CPU / PCH - unfortunately no way to swop any more. None of the inductors around the CPU are measuring as shorted though (~0.003V in diode mode, 35 ohms in resistance mode).

[@valinkakomputer]

@@therepairshare673I think u can try check the power good signal then