Laptop:
Hello, I have a System76 Gazelle laptop (model gaze14) which now only partially powers on and does not boot properly.
History:
This laptop has served me well for a few years. It's always been a bit noisy with the fans and recently became much more so on both fans, where just opening a vim/notepad session would cause the fans to spin up loudly and make a grating sound, like the ball bearing were mechanically wearing out. So after blowing the dust out of the fans out didn't help, I ordered replacement fans and heat sink component from System76 which were sold as a unit (1 CPU fan, 1 GPU fan, 1 connected Cu heatpipe/sink assembly). I opened the laptop up, swapped out the old heatsink and fans and installed the new ones. I also opted to try using Innovation Cooling Graphite Thermal Pad instead of thermal grease as I had done in the past. Knowing that the graphite pads were conductive, I made sure to carefully cut the pads to size after measuring the dimensions of CPU and GPU with calipers and not to let the pads touch other components, including while the laptop was unpowered. After happily re-assembling the laptop with the new gear ready to give it a spin, I pressed the power button, and it didn't boot. Yes, so it appears I have somehow caused damage during my fan/heatsink swap episode, perhaps a thermal pad induced short despite careful handling and placement; otherwise, I just got very unlucky that it happened to coincidentally fail after I worked on it.
Boot Observation:
- The laptop shows an LED indicator properly for AC_IN which is orange. When the lid is opened and the power button is pressed, the AC LED indicator turns green for about 3 seconds, then turns back to orange again and nothing happens: no LCD display change, no fans, nothing. This is repeatable.
- The laptop also shows a separate battery LED indicator properly (orange), and when it is charging (green).
Problem appears to be the motherboard:
- The problem is the same with or without RAM present, with or without M2 SSD storage present. Removing the CMOS battery temporarily and re-connecting does not resolve problem or change behavior.
- Removing the motherboard from the laptop, removing RAM and storage and disconnecting any extra circuit connector wiring to eliminate other possibilities (ie: disconnect CCD cable, USB board cable, touchpad cable, keyboard cable, CPU/GPU fans) and using only AC in with no battery present still results in same power on problem behavior.
Hardware Details:
- This computer appears to be a rebrand based on Clevo hardware, with a "Clevo CO Code" on the back of "NH58RA". I was able to find a service manual with schematics for this board. The part number on the motherboard is: 6-77-NH50RA00-D02B-1E#10. I'm not sure if it's appropriate to post the PDF directly or link to it (if I can still find it) since it's not directly from the Clevo website that I obtained it from, so I'll leave that out for now.
Hardware troubleshooting:
- Initial inspection of the board doesn't reveal any obvious physical damage anywhere
- Power jack, mosfets near power jack and random multimeter testing of various capacitors I can readily identify on the board don't appear to show any shorts to ground.
- The service manual does show the following power on steps, shown partially here, in order they are shown in the service manual, stopping at the first line item where things don't appear to be healthy. I used the circuit schematics to locate a component where I could test voltage of each respective item and identified the first issue which appears to be output of VDD1.05 which in this board's case, appears to be near 0V:
I checked a few line items further in the power on process after VDD1.05. The next line item is RSMRST and that appears to be normal. After that is DD_ON, and that's essentially also 0V. I suspect quite a few power on steps after that are also not normal, so I've started to try and locate the source of the problem where is it first seen, in the VDD1.05 circuit output.
It looks to me like the PU21 chip (see pic) should be generating VDD1.05 on pins 6, 19, 20. I measure voltage on either side of inductor PL16 and get near 0V. I measure voltage at other components in the schematics where VDD1.05 is shown and also get near 0V. PU21 chip does have VIN on pins 2, 3, 4, 5 of ~19.6V. I did look briefly at the other pins on PU21 which seemed either ok or inconclusive (I didn't record notes on the other pins so can't comment further than that at the moment).
Not sure exactly what to do for next steps in troubleshooting. I do not have an o-scope at the moment, just a multi-meter.
Thoughts:
- I suppose I might have possibly shorted the CPU/GPU or some components around it by trying out the graphite thermal pad despite conscious and careful handling and installation. I'm hoping I'm not to blame for destroying my own board, but who knows. Given the laptop had been running hot with the fans spinning high and also sounding like they were starting to die which prompted me to order replacement fan components in the first place, I also wouldn't be too surprised if this is completely unrelated to the thermal pads and some component just coincidentally died from overheating and the corresponding lifetime shortening in the weeks prior.
Any suggestions for further troubleshooting would be much appreciated. I don't yet know how to test the CPU and GPU for shorts or problems, but I'll be researching that soon to try and figure it out if I don't get anywhere with finding root cause for the lack of VDD1.05 signal.
Thank you!
John
Hello, I have a System76 Gazelle laptop (model gaze14) which now only partially powers on and does not boot properly.
History:
This laptop has served me well for a few years. It's always been a bit noisy with the fans and recently became much more so on both fans, where just opening a vim/notepad session would cause the fans to spin up loudly and make a grating sound, like the ball bearing were mechanically wearing out. So after blowing the dust out of the fans out didn't help, I ordered replacement fans and heat sink component from System76 which were sold as a unit (1 CPU fan, 1 GPU fan, 1 connected Cu heatpipe/sink assembly). I opened the laptop up, swapped out the old heatsink and fans and installed the new ones. I also opted to try using Innovation Cooling Graphite Thermal Pad instead of thermal grease as I had done in the past. Knowing that the graphite pads were conductive, I made sure to carefully cut the pads to size after measuring the dimensions of CPU and GPU with calipers and not to let the pads touch other components, including while the laptop was unpowered. After happily re-assembling the laptop with the new gear ready to give it a spin, I pressed the power button, and it didn't boot. Yes, so it appears I have somehow caused damage during my fan/heatsink swap episode, perhaps a thermal pad induced short despite careful handling and placement; otherwise, I just got very unlucky that it happened to coincidentally fail after I worked on it.
Boot Observation:
- The laptop shows an LED indicator properly for AC_IN which is orange. When the lid is opened and the power button is pressed, the AC LED indicator turns green for about 3 seconds, then turns back to orange again and nothing happens: no LCD display change, no fans, nothing. This is repeatable.
- The laptop also shows a separate battery LED indicator properly (orange), and when it is charging (green).
Problem appears to be the motherboard:
- The problem is the same with or without RAM present, with or without M2 SSD storage present. Removing the CMOS battery temporarily and re-connecting does not resolve problem or change behavior.
- Removing the motherboard from the laptop, removing RAM and storage and disconnecting any extra circuit connector wiring to eliminate other possibilities (ie: disconnect CCD cable, USB board cable, touchpad cable, keyboard cable, CPU/GPU fans) and using only AC in with no battery present still results in same power on problem behavior.
Hardware Details:
- This computer appears to be a rebrand based on Clevo hardware, with a "Clevo CO Code" on the back of "NH58RA". I was able to find a service manual with schematics for this board. The part number on the motherboard is: 6-77-NH50RA00-D02B-1E#10. I'm not sure if it's appropriate to post the PDF directly or link to it (if I can still find it) since it's not directly from the Clevo website that I obtained it from, so I'll leave that out for now.
Hardware troubleshooting:
- Initial inspection of the board doesn't reveal any obvious physical damage anywhere
- Power jack, mosfets near power jack and random multimeter testing of various capacitors I can readily identify on the board don't appear to show any shorts to ground.
- The service manual does show the following power on steps, shown partially here, in order they are shown in the service manual, stopping at the first line item where things don't appear to be healthy. I used the circuit schematics to locate a component where I could test voltage of each respective item and identified the first issue which appears to be output of VDD1.05 which in this board's case, appears to be near 0V:
Code:
VDD3 ~3.4V SLP_SUS# ~3.4V 3.3VA ~3.4V 1.8VA ~1.86V PWR_BTN# ~3.4V VDD1.05 ~0.01V <--- Looks like the first power on line item issue
It looks to me like the PU21 chip (see pic) should be generating VDD1.05 on pins 6, 19, 20. I measure voltage on either side of inductor PL16 and get near 0V. I measure voltage at other components in the schematics where VDD1.05 is shown and also get near 0V. PU21 chip does have VIN on pins 2, 3, 4, 5 of ~19.6V. I did look briefly at the other pins on PU21 which seemed either ok or inconclusive (I didn't record notes on the other pins so can't comment further than that at the moment).
Not sure exactly what to do for next steps in troubleshooting. I do not have an o-scope at the moment, just a multi-meter.
Thoughts:
- I suppose I might have possibly shorted the CPU/GPU or some components around it by trying out the graphite thermal pad despite conscious and careful handling and installation. I'm hoping I'm not to blame for destroying my own board, but who knows. Given the laptop had been running hot with the fans spinning high and also sounding like they were starting to die which prompted me to order replacement fan components in the first place, I also wouldn't be too surprised if this is completely unrelated to the thermal pads and some component just coincidentally died from overheating and the corresponding lifetime shortening in the weeks prior.
Any suggestions for further troubleshooting would be much appreciated. I don't yet know how to test the CPU and GPU for shorts or problems, but I'll be researching that soon to try and figure it out if I don't get anywhere with finding root cause for the lack of VDD1.05 signal.
Thank you!
John
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