Yeah good tips , Could not find a coin cell, ( after your post I double check and found the cell ) and I had the main board out of the system. I pulled and reset every ribbon cable. I was actual hoping I would cause some real damage so it would not even poweron, call it a total loss and move on. But no it till powers on to that Asus logo . I should have done a reset bios default and will try that if I can get back in. I must have tried a hundred time today no go. The laptop was working fine and I recall all this started after a windows update. On one of failed boot attempts I recall seeing an error message, text on the bios screen that I googled and found a link to a fail Intel management engine firmware update. I suspect that this was pushed out via Windows Update, failed and and is not stopping the boot process for working.Hugh wrote: ↑ Bummer.
Getting the logo on screen means a lot of the system is working. That's hopeful.
Being able to enter the firmware setup screen is even better.
Here are some easy things to try:
When you were in the settup screen, did you look around at the current settings? Did any of them look odd? Does it see the SSD? Does it see the RAM?
Can you reset the firmware settings to the default? If so, does that make any difference?
Most notebooks have two batteries: the big rechargeable battery, and the "CMOS" battery, a little coin cell that allows the firmware settings and the clock to function with no mains power. Is that coin battery dead?
(Since two out of two of our UX305CAs had SSDs die, I'm quite suspicious of them. But it sounds like you've ruled that out.)
Sometimes a connector stops working perfectly. Perhaps it has worked loose. Perhaps a little corrosion develops on the contacts. Disconnecting and reconnecting them often fixes such a problem.
Since you are having trouble powering off, the first connector I'd look at is the one that connects the power button to the motherboard (or whatever).
The second would be the keyboard (probably a weird ribbon cable connector: be careful, there might be a clamp you have to release). If you really did remove the motherboard, you probably already did this.
after finding the coin cell I removed, it no change so I removed the ribbon cable for the the entire daughter board and still no change only booting the Asus logo.
the oin cell is in red on this picture.