First, welcome. As for the code resetting literally resets everything. Pricing, and other settings. The manual should tell you how to reprice. If you still need help just ask.

Yep, the converters have trouble reporting which selection, as that info is not transmitted over the MDB cable. In order to get sales info, you must have and aftermarket board capable of the DEX protocol. The USAT modem can then get the info through that.

Can't be. The factory board on these machines did not support CC readers or sales data. It most certainly is an aftermarket/retrofit board. Question is, which brand? The two most common are Vendors Exchange UCB and inOne. If you can't figure it out, just post a pic and we can tell you.

Scam.

Welcome. Your machine is actually a Royal Vendors, not a DN. It is part of the GII series, not to be confused with the later GIII. As for the manual here it is. https://www.royalvendors.com/gii-vender/

Just don't lick the paint, and youll be fine.

Using 2 can actually cause issues.

That funny looking thing is an in-line GFI. Also the electrician should be able to figure it out. Good luck.

That was a later machine. DN updated the coin insert to the E series style, but the rest of the machine is the same. I’ve personally seen 368s, 440s, and 501Ts done up like that. I have also seen single price 501Es, that DN confirmed left the factory as single price (technically 501ERs).

Take some pics of the column walls.

RPD (Raddatz Products Development) combo. https://rpdvending.com/ I'm personally not a fan of these machines. No one knows about them and they look dated. Edit: Maybe a Venex? Not too sure.

You want the thermostat to measure the air temp accurately, but if its touching something it will be affected by the temperature of the sheet metal by conduction.

GFIs are not breakers. They don't care about too much current. The only thing they will trip for is current that goes out the hot, and leaks and doesn't return to the neutral or ground. Or if the GFI is defective. Now too many devices on the same GFI (not circuit) can cause it to trip, as each device can leak a bit of current, which can add up to the threshold to trip a GFI. So you either have chafed insulation or poor ground connections. Or there is another GFI upstream that is causing this one to trip. Or the electrician installed a cheap golpher GFI that trips cause the run and start caps on the compressor store some electricity, causing the GFI to think there is an issue.

If it’s still tripping after getting a new GFI there is something wrong with your machine. Running it without a GFI is like taping over your airbag light and pretending everything is ok.

Didn’t Coinco own Royal or something like that?