Lenovo g500 switch on and off after 5 seconds

[NConstantinou]

Testing the mono I found that I have short on +vcc_core, +1.05s_vccp and +vcc_gfxcore_axg
I disconnected all positive side of 330u capacitors near CPU and I still have short.


Does anyone has any idea!

Thanks

[piernov]

Re: Lenovo g500 switch on and off after 5 seconds

Exact resistance to ground on those? Higher than a couple of ohm is not a short on a CPU power rail.

[NConstantinou]

Re: Lenovo g500 switch on and off after 5 seconds

I will test tomorrow and I will let you know.
One more thing, under CPU there are 5_6 capacitors that are shown as short, and if CPU is install the PL905 is shown short to ground. If I remove CPU PL905 is not short that is the pl1 +vcc_gfxcore

[mcplslg123]

Re: Lenovo g500 switch on and off after 5 seconds

Cpu/gpu power rail always has very low resistance as piernov has said. I'll check first whether you have 5/3.3v VS voltage.

[NConstantinou]

Re: Lenovo g500 switch on and off after 5 seconds

+vcc_core has 15ohms.
I do have 3.3 and 5v VS

[NConstantinou]

Re: Lenovo g500 switch on and off after 5 seconds

The resistance +vcc_core is 15ohms.

I do have 3.3 and 5v VS

[ibrahimtatli]

Re: Lenovo g500 switch on and off after 5 seconds

change the bios chip

[tahc81]

Re: Lenovo g500 switch on and off after 5 seconds

15 ohms is acceptable for those rails. Let's imagine the startup sequence. EC (embedded controller) after power button press is checking the voltages, temperatures, maybe presence of some HW, buttons, lid... etc. If anything of these goes bad, EC will shutdown the laptop (mostly the VRM controllers generating all other voltages than 3V3 and 5V.

In your case, it can be also SW issue, EC BIOS corruption, failed EC chip, or any other issue mentioned in a previous paragraph.