Hello people,
I've got this laptop not working for repairs, and as you can see something was done to it as you can see in the coils PL58XX (which I for some reason cannot find in the schematics...) The first FET (PQ201) was not an original part and a questionable one at that and the second one (PQ202) was shorted. Both are N-channel. Ordered replacements for them and replaced them after arrival. Now I have encountered another problem: there is no power at the second FET. By following the thread linked I got to the injection part. Applied 0.8V at 1.5A, but couldn't feel anything getting hot, so upped it to 1V at 2.5A and to my relief the PCH nor the CPU is getting hot. What is though, is the area near the first FET. I don't have a thermal camera, so further troubleshooting is an issue. I suspected that one of the caps gone bad, just in case did measurements that I put in the photos, but it's conflicting with what seems most likely the first FET getting hot, but I feel heat in the general area of it. Help will be much appreciated! I'm attaching a schematic for this board, and a few photos.
Measurements:
Main rail (VIN) is 20.6V
PF101 has continuity, so it's not the fuse
None of these 5 caps have the same voltage on both terminals
PQ201:
S-D - 20.2V, 2.8MΩ
S-G - 0V, OL
D-G - 20V, OL
PQ202:
S-D - 0V, 3.5MΩ
S-G - 0V, 3.8MΩ
D-G - 0V, 5.2MΩ
ACDET is 2.8V
ACOK is 0V
I've got this laptop not working for repairs, and as you can see something was done to it as you can see in the coils PL58XX (which I for some reason cannot find in the schematics...) The first FET (PQ201) was not an original part and a questionable one at that and the second one (PQ202) was shorted. Both are N-channel. Ordered replacements for them and replaced them after arrival. Now I have encountered another problem: there is no power at the second FET. By following the thread linked I got to the injection part. Applied 0.8V at 1.5A, but couldn't feel anything getting hot, so upped it to 1V at 2.5A and to my relief the PCH nor the CPU is getting hot. What is though, is the area near the first FET. I don't have a thermal camera, so further troubleshooting is an issue. I suspected that one of the caps gone bad, just in case did measurements that I put in the photos, but it's conflicting with what seems most likely the first FET getting hot, but I feel heat in the general area of it. Help will be much appreciated! I'm attaching a schematic for this board, and a few photos.
Measurements:
Main rail (VIN) is 20.6V
PF101 has continuity, so it's not the fuse
None of these 5 caps have the same voltage on both terminals
PQ201:
S-D - 20.2V, 2.8MΩ
S-G - 0V, OL
D-G - 20V, OL
PQ202:
S-D - 0V, 3.5MΩ
S-G - 0V, 3.8MΩ
D-G - 0V, 5.2MΩ
ACDET is 2.8V
ACOK is 0V
Attached Files
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