Hp Probook 640 Won't Power Up

[pat21784A]

Hi, I'm a field service tech with a frustrating problem.  HP Probook 640 G1, initial customer complaint was that the system will charge battery when turned OFF and plugged in, but system will not charge battery or use wall power when turned ON.

Battery and power cable were replaced; no change.  Conclusion at that point was a problem existed between the power cord and power connector on the system board; thus the system board was replaced. 

Since then, the laptop will not power up at all, on battery or when plugged into the wall. 

Today I replaced the power button board, and got the same symptoms, but noticed that when I press the power button, the battery indicator LED blinks nine times and stops; nothing else happens. 

Any suggestions would be greatly appreciated.

[Omar-E]

@pat21784A

‎Thank you for using HP Support Forum. I have brought your issue to the appropriate team within HP. They will likely request information from you in order to look up your case details or product serial number. Please look for a private message from an identified HP contact. Additionally, keep in mind not to publicly post ( serial numbers and case details).

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Thank you,
Omar

[pappap]

Hello, I have run into the same problem problem with the HP Probook 640 G1 not powering on when the power button is depressed and have swapped out battery and power supply, but no joy.  What fixed it for you.  Please advise.

[JRL305]

I've got a 640 G2 with the sam problem.  Was this ever sorted out?

[NealHalverson]

I am a certified HP technician, and me and my team have been experiencing this issue with 640 G1's and 640 G2's.
More with G2's, another tech from our team has encountered 3 this week.

This is after doing the reset protocol.

Our only option has been to replace the motherboard.