It seems like game gear turn on short circuit protection, probably everdrive draw too much in impulse during cold start. It happens with some gamegears and no any problems with other, maybe depends from console board revision
Hi KRIKzz,
I have this same problem with 3 of my 4 Game Gears. The one Game Gear where the Everdrive always starts correctly is the one that shows the bootup message "PRODUCTED BY OR UNDER LICENSE FROM SEGA ENTERPRISES LTD.", my other Game Gears don't have a bootup message and go straight to the SEGA logo.
I hope this can help you fix the problem and release a new firmware.
Can the others that have this same problem also confirm that they have this bootup message or not?
Same problem here. I have 4 Game Gears. 2 of them start with "PRODUCED BY OR UNDER LICENSE FROM SEGA ENTERPRISES LTD.", and the Everdrive
GG boots everytime.
The 2 Game Gears without that message (which I presume are early
VA0 models)
fail to boot the Everdrive GG very often. In cold start I usually need 2 or 3 boots for the Everdrive to work properly, and If I reboot the GG when I've been succesfuly playing with the Everdrive, I need to wait for about 5-10 seconds, or the Everdrive will
never boot.
I've tried to change the power board from a working GG into the problematic ones, but same problem. This issue is not related to the power board, but the main GG board.
One of my VA0 GG model is LCD Modded (McWilll), and it's very frustrating not being able to enjoy its beautiful screen...

KRIKzz, could you send us a new firmware to correct this issue in the first Game Gears?
I can be your betatester for this issue, if you want. I've noticed that If I push the GG power button very quickly, the false starts are minimized greatly, so it could be a timing issue. One of the first things I would try would be delaying the Everdrive Boot cycle for this test firmware, if you can.
Thanks!