Hi, I want to ask for advice about an interesting issue I've been having with a sony vaio laptop.
Client came and said that "a desklamp touched the back of the lid while laptop was operating normally and it caused the office's circuit breaker to trip. Laptop had never turned on since".
After taking the laptop apart (checked dc adapter everythin ok), I found a faulty MOSFET on the motherboard which I replaced. Laptop managed to turn on. However, while booting it shut down. Nothing else seemed faulty and thermals were ok. Shutting down was coming at random times while booting, either at windows logo, at post, at windows login screen, etc.
After some testing, I accidentally discovered that the laptop stays on at all times when connected via vga cable on an external monitor. Same thing happens when a USB A-A is connected on another pc. Same thing happens when a vga cable is connected on a working gpu on a pc.
Same thing does not happen when laptop is connected to a power bank. It does not happen when I ground the laptop (touching the shield of a usb to the earth of a power plug). It doesn't seem to work whith any another way except of the above.
This problem puzzles me and I do not understand why it happens. It sound like it has to do with the ground. Any ideas? Thanks!
Client came and said that "a desklamp touched the back of the lid while laptop was operating normally and it caused the office's circuit breaker to trip. Laptop had never turned on since".
After taking the laptop apart (checked dc adapter everythin ok), I found a faulty MOSFET on the motherboard which I replaced. Laptop managed to turn on. However, while booting it shut down. Nothing else seemed faulty and thermals were ok. Shutting down was coming at random times while booting, either at windows logo, at post, at windows login screen, etc.
After some testing, I accidentally discovered that the laptop stays on at all times when connected via vga cable on an external monitor. Same thing happens when a USB A-A is connected on another pc. Same thing happens when a vga cable is connected on a working gpu on a pc.
Same thing does not happen when laptop is connected to a power bank. It does not happen when I ground the laptop (touching the shield of a usb to the earth of a power plug). It doesn't seem to work whith any another way except of the above.
This problem puzzles me and I do not understand why it happens. It sound like it has to do with the ground. Any ideas? Thanks!
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