GameBoy Pocket Holding Contrast Issue

I have a GameBoy pocket that I've had since I was a kid and I when using the EverDrive GB and swapping roms it shuts off. When playing normal GB carts the contrast will get lighter and darker randomly so I have to keep adjusting it as I'm playing. The GB everdrive cart swaps roms just fine on my GBA SP, so it's not the cart.

When opening the GameBoy it was covered in kinda oily residue and used alcohol to clean it off. Is it possibly a blown capacitor? The capacitors look like this -

The sound works perfect, the power always turns on, so just this strange contrast issue and the oily board and everdrive GB not being able to change roms are the issues.

Another concern is when I was a kid in Wisconsin I left my GB in the car for a few days and now the screen has mad motion blur. Not sure if related, or a separate issue to fix. I tried googling these issues, I came up with nothing. Here's a stock pic of the model GB Pocket I have.

 

GB Pocket has had issue with Everdrive. It barely puts out enough power from the power board to run a stock GBP with a game. ED draws a lot of power and is known to cause GBP to randomly shut down. There's some posting about this issue on Krikzz forum.

Don't remember if they found a solution, I use GBA-SP model 101 and it has worked fine the whole time.

 

Maybe this thread? - http://krikzz.com/forum/index.php?topic=1972.15
Says buying 1.6v batteries will make it work, 1.2v is too little. But I have 1.5v batteries and I still have issues.

UPDATE: I ordered some of these 1.6v batteries and I'm going to give it a try.

 

Gave the new 1.6v batteries a try, and it fixed both the contrast issue and the EverDrive issue.