Hello everyone,
I'm trying to repair my old Acer Nitro 5 (AN517-54-55T5). I've already bought a new laptop, so this is more of a learning project. For the experience, with no high expectations of success.
Well, my decice specs are the following:
Model: Acer Nitro 5 AN517-54-55T5
CPU: Intel Core i5-11400H
GPU: NVIDIA GeForce GTX 1650
Motherboard: GH51G LA-L181P Rev:1c
The symptom:
When pressing the power button, the power LED lights up for about 5 seconds and then turns off. Initially, the issue was intermittent: sometimes it would occur, and hours later, the laptop would boot up fine. The fault usually manifested after the laptop had been off for a long time. When it was running, there were no issues or BSODs. If restarted or shut down and turned back on shortly after, it would always boot normally. Eventually, the issue occurred, and the laptop never powered on again.
I've made some measurements Based on the motherboard schematic:
+3VALW and +5VALW rails are present.
+3VALWP rails appear for the 5 seconds the LED is on (and briefly after), then disappear.
I couldn't find the +1.8V and +1.05V rails. The coils for both these rails showed a short to ground.
I opened the jumper PJ1801 (as per the schematic) to isolate the circuits. The short on the +1.8V rail disappeared. This leads me to believe that the issue is on the +1.05V rail?
When investigating the +1.05VALW circuit, the schematic is a bit confusing. It mentions a jumper PJ1101 which is not physically present on my board; I wanted to open it to further isolate the short.
I couldn't find direct references to a voltage named +1.05VALWP. I interpreted this rail to be +VCCIN_AUX_PCH. Is this correct?
The coil for the +VCCIN_AUX_PCH rail (which I believe is the +1.05V rail) is shorted to ground.
Since there's no jumper to isolate this section, I removed the coil to check if the short was on the power delivery side (before the coil) or on the PCH side. (I'm not sure if removing the coil is the ideal procedure here, is it?).
After removing the coil, the short remained only on the PCH side pad.
Well, at this point, all signs point to a faulty PCH (Platform Controller Hub). The initial intermittent nature of the problem made me suspect, BGA soldering issues?
I considered injecting voltage (low current, ~1V) onto this rail to see if anything on the PCH heats up and confirms the faulty component. However, I don't have an adjustable power supply and I'm hesitant to try using an alternative power supply, there is a way to do securely without a current and voltage limited power supply?
OH! I noticed a slight yellowish discoloration on the PCB, directly underneath the PCH. Could this indicate overheating and be the cause of the problem? I've read online that on some Nitro models, the PCH can overheat and fail due to heat from the NVMe SSD positioned directly above it. Does this make sense? I used this laptop with two NVMe SSDs and one SATA SSD, often performing heavy, simultaneous file transfers between them for hours (Python scripts processing and moving images).
Well I'd appreciate some guidance on how to proceed. Are there any other lines of investigation I could pursue or tests I could perform?
Since this board has become a learning project for me, I'm seriously considering buying a new PCH and attempting a DIY replacement (with a hot air gun and preheating with aelectric barbecue​). I know it's risky and the chances of success are low, but I'd be doing it more for the experience and fun than with any real hope of a fix lol
Anyway, i just need a path, thanks for any help or suggestions!
I'm trying to repair my old Acer Nitro 5 (AN517-54-55T5). I've already bought a new laptop, so this is more of a learning project. For the experience, with no high expectations of success.
Well, my decice specs are the following:
Model: Acer Nitro 5 AN517-54-55T5
CPU: Intel Core i5-11400H
GPU: NVIDIA GeForce GTX 1650
Motherboard: GH51G LA-L181P Rev:1c
The symptom:
When pressing the power button, the power LED lights up for about 5 seconds and then turns off. Initially, the issue was intermittent: sometimes it would occur, and hours later, the laptop would boot up fine. The fault usually manifested after the laptop had been off for a long time. When it was running, there were no issues or BSODs. If restarted or shut down and turned back on shortly after, it would always boot normally. Eventually, the issue occurred, and the laptop never powered on again.
I've made some measurements Based on the motherboard schematic:
+3VALW and +5VALW rails are present.
+3VALWP rails appear for the 5 seconds the LED is on (and briefly after), then disappear.
I couldn't find the +1.8V and +1.05V rails. The coils for both these rails showed a short to ground.
I opened the jumper PJ1801 (as per the schematic) to isolate the circuits. The short on the +1.8V rail disappeared. This leads me to believe that the issue is on the +1.05V rail?
When investigating the +1.05VALW circuit, the schematic is a bit confusing. It mentions a jumper PJ1101 which is not physically present on my board; I wanted to open it to further isolate the short.
I couldn't find direct references to a voltage named +1.05VALWP. I interpreted this rail to be +VCCIN_AUX_PCH. Is this correct?
The coil for the +VCCIN_AUX_PCH rail (which I believe is the +1.05V rail) is shorted to ground.
Since there's no jumper to isolate this section, I removed the coil to check if the short was on the power delivery side (before the coil) or on the PCH side. (I'm not sure if removing the coil is the ideal procedure here, is it?).
After removing the coil, the short remained only on the PCH side pad.
Well, at this point, all signs point to a faulty PCH (Platform Controller Hub). The initial intermittent nature of the problem made me suspect, BGA soldering issues?
I considered injecting voltage (low current, ~1V) onto this rail to see if anything on the PCH heats up and confirms the faulty component. However, I don't have an adjustable power supply and I'm hesitant to try using an alternative power supply, there is a way to do securely without a current and voltage limited power supply?
OH! I noticed a slight yellowish discoloration on the PCB, directly underneath the PCH. Could this indicate overheating and be the cause of the problem? I've read online that on some Nitro models, the PCH can overheat and fail due to heat from the NVMe SSD positioned directly above it. Does this make sense? I used this laptop with two NVMe SSDs and one SATA SSD, often performing heavy, simultaneous file transfers between them for hours (Python scripts processing and moving images).
Well I'd appreciate some guidance on how to proceed. Are there any other lines of investigation I could pursue or tests I could perform?
Since this board has become a learning project for me, I'm seriously considering buying a new PCH and attempting a DIY replacement (with a hot air gun and preheating with aelectric barbecue​). I know it's risky and the chances of success are low, but I'd be doing it more for the experience and fun than with any real hope of a fix lol
Anyway, i just need a path, thanks for any help or suggestions!
Attached Files
