HP ENVY 360 Model 15-w237cl does not power on (solution found)

[matmasr]

So I bought two identical of these laptops from Sams Club a few years ago.  After about 1.5 years of use, the power on the laptop started to act strange.  The firs laptop would sometimes not properly shut down when I select the shut down option from the Windows menu.  The screen would go blank but the power button light would remain illuminated (white color).  The only way it would completely shut down is if I held the power button  for a few seconds.  Also sometimes it would not go into sleep mode or shut down mode when the screen is closed.  These issues were more of an annoyance rather than a serious issue.  However, after a while the laptop stopped powering ON all together no matter how many seconds I hold the power button in an attempt to do a power reset.   Sometime the light on the power button would come on, but the laptop would not go into it's boot sequence. Other times, it acted like a brick.  In all cases, when the power cord was plugged in, the charging light would also be on, which meant the system was getting power and the battery was charging, but the laptop would not power on. 

After giving up, I took the first laptop to Geek Squad, as HP support told me they are their authorized repair center based on my location and the fact that I was out of warranty.  After THREE months , yes three months of many issues with the repair process,  the finally rebuilt the laptop with another motherboard, which to me was ridiculous as the laptop was only about 1.5 year old.   Since then this first laptop has been working well for more than a year now. 

The second laptop, within a few months of the first one, started showing the same issues with powering on but I decided to shelve it.   I didn't want to deal with Geek Squad repair center anymore.  Then in about a couple of weeks ago, as I was cleaning found the bricked laptop and decided to attempt a motherboard repair myself.   I ordered a new motherboard from China as it was very hard to find and VERY expensive as well.  Unfortunately, after two weeks of waiting they refunded my money and told me the motherboard is no longer available.  By the way the motherboard part number is 859660-601. 

So as a last resort, I read once more through some of the posts here and attempted the solution offered by user @Jy2 here https://h30434.www3.hp.com/t5/Notebook-Operating-System-and-Recovery/HP-Envy-Touchsmart-15-won-t-tur...

Disassembled the rear cover, unplugged the main battery cable and (VERY IMPORTANT) unplugged the CMOS battery cable from the motherboard.  The CMOS battery is the small round coin-looking battery on the right hand side.  It is covered in a black sleeve so it may be hard to recognize.   Be careful with the cable, it is easy to break.   Anyways, waited for a couple of minutes, replugged back the battery cables  then turned on the laptop and to my astonishment  IT WORKED !  No need to replace mother board.  I did notice that powering down using the Windows Power Off feature is still not working properly which is something that might be repaired with a BIOS update.   I hope this post helps.