AtariMax 128-in1 and Garbled Graphics

[Paranoid]

Not sure where to start here. I had two Colecovision consoles, one with the AV mode and a DB-9 passthrough on the side for connecting another joystick (say, an Atari CX40, use the keypad from p1 with an Atari joystick). I had a single power supply for the two of them. The other one is pretty beat up and has no mods.

I have the Atarimax 128-in1 USB cartridge.

A while ago, I started seeing problems with garbled graphics on either one of them. I thought it might be the power supply, although the Multicart gives a video memory error on the Multicart USB test, same address with both consoles. Once I load a game, I get video artifacts - lines and garbled graphics, sometimes worse than others - but I can never get a game to load without garbled graphics. An example is Montezuma's Revenge. The "chain" barriers NEVER disappear, even when they are safe to pass.

Today I bought a new Colecovision, with AV mod and power supply. Brought it home, and the initial problem is that as soon as I insert the Multicart, it selects slot 1 on the cart. If I hold the joystick down while powering it on, it will scroll through all of the games and the minute I let it go, it selects the game in that slot (or no game if an empty slot). Once I get into a game, the garbled graphics were still there. When I go into the USB Multicart Diagnostics - I can't select options 1, 2 or 3 to run tests... it is as if there is a stuck button input (the same thing that is causing it to automatically select slot 1 at power on, is my guess.)
I tried the power supply with my original AV modded Coleco - and got the same results. I tried Gorf in the original AV modded Coleco, and it had garbled graphics too. Put that cart in the newly purchased one, and it worked.

So then I pulled out the NON AV modded Coleco, put it on the new power supply, and the Multicart works fine, and Gorf works fine - and when I go to the Multicart USB Video Ram test, now it passes the test (and I realized that before on the original power supply, it was failing the video ram test immediately, because I see that it runs a number of video screens to determine if the video is fine.)
So the only thing that works is the NON AV modded Colecovision but only with the NEW power supply.

This is less than ideal.

Any thoughts?

Does Chuck from AtariMax still hang out around here? I think that is his name. It has been a long time since I was a regular on this forum.
It seems like I may have a dying power supply that I was using between my two original consoles, but it seems like the new power supply only works right with the non modded console and the multi-cart - the multi-cart barfs on both the modded CVs. The NEWEST CV has a standard BIOS, but the other AV modded unit has an enhanced bios. The non-modded one has a standard BIOS also. Does the AtariMax Multicart have known issues with AV modded Colecovisions? Does anyone sell refurbed Colecovision power supplies or repair them?

I can include some screen shots of the video ram error and how the graphics look, if it would help.

[Paranoid]

So, the only thing I *haven't* tried is the newly purchased console with the old power supply.

[Paranoid]

So, if I take the original single power supply I have and I plug it into the new console, Gorf has the distorted graphics - so the problem with graphics follows the power supply.
Here is what it seems like
Non AV modded console is fine - but I have a bad power supply. With the power supply from the new console, all problems go away.
Original AV Modded console has a video problem that manifests even with the new power supply. Clearly the old power supply isn't going to help things out any if it doesn't work with the non-modded console.
The new console has some sort of problem with the joystick input registering a constant fire button, even with the joysticks removed... but this only manifests itself in the Atarimax Colecovision 128-in-1 cart. Once I am into a game, the firebutton works fine - it isn't like it is stuck on autofire. Which is weird.
I wish the Coleco Flashback had an SD slot. I love Colecovisions - but they're one of the most unreliable retro-consoles to collect.