Gateway P6822 Hangs On Gateway Logo Startup Screen

I have a Gateway P6822 that has been upgraded with an SSD running Win 10 64 bit. Recently it started hanging on the startup screen. This is the screen that apears after pressing the power button that says press F2 for bios setup and F10 for Boot options. Sometimes it might hang with a blank screen.

If I enter the bios and set bios defaults save and exit it might boot normally. It seems temperamental. Sometimes it will boot normally and sometimes it hangs.

I have tried removing the battery and power cord and pressing the power button to discharge the capacitor and reset. I have run Windows memory diagnostic and it found no errors. I have cleaned the fan. The heat sink has been cleaned and reseated with new thermal paste. I have removed and reinserted the SSD in case there was a bad conection. I have tried reinserting the old HDD and that does not solve the problem. I have tried removing the old aged battery but that does not help. I have upgraded to the latest bios and plan to do a Win 10 repair install in case that helps. Win 10 fast boot is enabled. I don't know if that will make any difference.

Is there anything else that might be causing this problem? Your advice would be apreciated.

Kind regards
Chris