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My hp envy x360 15m-ed0023dx won’t turn on; no lights or screen display or fan noise: completely dead. The power jack lights up when plugged in and I can detect voltages on the motherboard from the power jack to the battery, which also shows power. The one fuse I located (marked fu2) has continuity and the power button* (integrated in the keyboard) checks out good as well. I tried a hard reset a couple of times but no luck. Also tried pulling the ram and replacing one by one. No change. The power supply checks out good. At this point I’m thinking it’s a bad motherboard so I ordered one.This is a little difficult to believe since the laptop isn’t even 2 years old. But unfortunately out of warranty. How I checked the power button First I separated the palmrest/keyboard assy from the screen. Then I placed a foam rubber “foot” on the power button.
Then I flipped the assy over so it rested on the “footed” power button which activated it and enabled access to the motherboard keyboard cable. In the picture the motherboard is removed, with the keyboard cable taped down with pin side up. Using a multimeter equipped with needle-sharp (fine-tipped) probes, I tested the pins in pairs (figuring the power button involved two pins) until I discovered the relevant pair, counting from the left pins number 13 and 14, which showed continuity, so the button is good.
@PC Techneer Desperate times call for desperate measures. I assume that when you checked the power switch it was for continuity when operated but did you also check if there was a voltage on one side of the switch at normal? Have checked a few HP laptop motherboard schematics (Not GPC ) but all with no separate RTC battery and what they have in common is that there is still a designated RTC battery circuit in them except the power comes from the main battery and not a separate RTC coin cell battery. This battery supply rail is known as VCC3SW (the SW is for the power switch circuit). This voltage supply is fed via a fuse to the power switch but here’s the rub. The fuse has a different designation depending on the motherboard although two did mention F38 but this may be just a coincidence I realize that you have a new motherboard but this may not stop the fuse having been blown when the new motherboard was connected etc, if there was a problem in the power switch power supply circuit somewhere external to the motherboard. Is there a reset button somewhere perhaps on the laptop as the VCC3SW voltage feeds more than the power switch, but mainly different components on the motherboard? The switch voltage supply is fed from the main battery but again the pin on the battery connector is different although pin 6 rates a mention a few times. Perhaps you could check if there is a voltage present (I’m assuming 3V since the schematic designation has a 3 in it) on one side of the power switch when the laptop is off. This voltage is applied to the motherboard chipset (south bridge) to turn on the laptop, when the switch is operated If there isn’t a voltage present on the power switch, measure the voltages on the battery connector pins and check if one is 3V. If there is no 3V on any battery terminal then as you say, it may be a faulty battery. Most schematics show an 11 pin connector to the battery with earth at one end usually pins 10 &11 Really long shot, but maybe this is worth checking out in case it is the same or similar to yours.
