Hi all!
I have a Lenovo G580 Model 20157 with a LG4858 UMA MB and I was wondering if someone could help me troubleshoot it.
I have actually been given one of these before and it had the same symptoms--I press the power button and the webcam light, fan, and power light come on immediately. The fan stays on for about 9 seconds then stops. The fan will start again a minute or two later, stay on for a good while, then stop again. After this second fan cycle the laptop turns off. Throughout this whole process there is no video output. I don't have an external monitor to try, unfortunately. This is with no peripherals attached.
With this particular laptop, it was working when I got it, but then I went to install a new wireless card and stripped the screw. So I carefully taped up the motherboard and hit the screw with a dremel while collecting the metal filings with a hard drive magnet. Then I used hand powered air duster to clean the board off thoroughly before applying power. After I did this, that's when the problem started.
No wireless card is currently installed. The BGA chips were all under a glued down plastic insulator sheet so I think they were safe.
The screw post I dremeled on is mounted above the HDD1 connector on the top side and KB58 the keyboard connector on the bottom. All the graphics power is on the other side of the board...
Some measurements:
5V_S0 OK
3D3V_S0 OK
1D8V_S0 OK
1D5V_S0 OK
0D85V_S0 OK
0D75V_S0 OK
VCC_CORE OK
RTC bat 3V
VCC_GFXCORE dead--2mV on both sides of the inductor PL4401 vs ground.
Associated MOSFET PU4402 gets DCABATOUT OK.
No signal on the driver PU4401: PWR_GFX_CORE_DRVL, PWR_GFX_CORE_DRVH, and PWR_GFX_CORE_GPWM all have no signal.
VCC_GFXCORE to ground with processor removed 364 ohm. (too low?)
No visible shorts to the visible balls under the processor socket or PCH.
PCH chip gets really hot. Not sure if that's normal.
Swapping ram slots / different ram does nothing.
Hall effect sensor OK.
Any advice would be much appreciated. Thanks!
I have a Lenovo G580 Model 20157 with a LG4858 UMA MB and I was wondering if someone could help me troubleshoot it.
I have actually been given one of these before and it had the same symptoms--I press the power button and the webcam light, fan, and power light come on immediately. The fan stays on for about 9 seconds then stops. The fan will start again a minute or two later, stay on for a good while, then stop again. After this second fan cycle the laptop turns off. Throughout this whole process there is no video output. I don't have an external monitor to try, unfortunately. This is with no peripherals attached.
With this particular laptop, it was working when I got it, but then I went to install a new wireless card and stripped the screw. So I carefully taped up the motherboard and hit the screw with a dremel while collecting the metal filings with a hard drive magnet. Then I used hand powered air duster to clean the board off thoroughly before applying power. After I did this, that's when the problem started.
No wireless card is currently installed. The BGA chips were all under a glued down plastic insulator sheet so I think they were safe.The screw post I dremeled on is mounted above the HDD1 connector on the top side and KB58 the keyboard connector on the bottom. All the graphics power is on the other side of the board...
Some measurements:
5V_S0 OK
3D3V_S0 OK
1D8V_S0 OK
1D5V_S0 OK
0D85V_S0 OK
0D75V_S0 OK
VCC_CORE OK
RTC bat 3V
VCC_GFXCORE dead--2mV on both sides of the inductor PL4401 vs ground.
Associated MOSFET PU4402 gets DCABATOUT OK.
No signal on the driver PU4401: PWR_GFX_CORE_DRVL, PWR_GFX_CORE_DRVH, and PWR_GFX_CORE_GPWM all have no signal.
VCC_GFXCORE to ground with processor removed 364 ohm. (too low?)
No visible shorts to the visible balls under the processor socket or PCH.
PCH chip gets really hot. Not sure if that's normal.
Swapping ram slots / different ram does nothing.
Hall effect sensor OK.
Any advice would be much appreciated. Thanks!
Comment