Turns out the HHL frontlight needs to be soldered to different points. Did that and it works flawlessly.

Try disconnecting and reconnecting the ribbon cable from the board. Also check the bottom wire on your frontlight power connection, it looks like you may be bridging two points.

I don't think the bottom one is bridged but I will de/resolder that point.

I did have a bit of trouble plugging in the ribbon cable now that you mention it, but it doesn't explain why the LED is so dim.

So I'm modding my own GBC with internal prosound and LOCA frontlight and I've run into a major issue. The gameboy won't boot, but not in the traditional sense. Regardless of there being a cart or not, the screen will turn on and nothing will show. There's also no sound coming from the speaker. I've tried several batteries to see if the initial ones were defective or dead but to no avail.

Here are some pictures of the places I have touched/modified
https://imgur.com/a/KfYwb

I tested the system before modding anything at it worked just fine.

Any help in figuring out what's going on here would be greatly appreciated.

Thanks!
-Sam

PS: Yes I removed EM2 and EM3 for the prosound mod. This shouldn't affect the audio coming from the speaker though, as it (to my knowledge) only bridges the signal from the pot to the left and right channels for the audio jack.