I recently picked up a "not working" Toploader to try and repair. On testing, all I get is a grey screen. I get the same grey screen if there's no cart installed. The cart is fine, the cart slot is fine. Cleaning won't have any effect, but it's as if the system doesn't even acknowledge a cart installed. What is the screen on a working toploader normally like if you try and boot it up without a game?

When I opened it, there was some significant orange stuff on the bottom of the casing, indicating something spilled. There are some spots on the board, but it's mostly clean.

I've re-capped the whole system, but still getting the grey screen. I've tried some troubleshooting, and found some peculiar issues.

1. Reset switch wasn't working. I could not get continuity across the switch when engaged. I've desoldered and cleaned it, but haven't put it back on yet.

2. Voltage Regulator and fuse are good. I get 12v in, and 5v out.

3. I get 5v from the ground. This I found odd. I'm not sure where this would come from, whether the chips are defective and sending voltage where it shouldn't, or there's somehow a short somewhere. I do NOT get continuity between all 5v sources and ground. I'm in the process of searching for a short. Even more peculiar, is while powered with the AC unplugged, I still read 5v off the ground ONLY if the RF plug is installed. If unplugged, I lose 5v. I've never tested this with other systems, however I know the RF works, as I use it on my NES frontloader.

Any suggestions on what I can check? Any common culprits?