When I got my Shuttle it came with no power. When I found a wall wart with the correct rating, all I got was a green/blue screen (like if you had a bad card connection) with some wavy lines. It turned out to be a bad wall wart, the only thing I could not test was the amps so I assume that was the issue. I found another correct rating PSU and it's been fine ever since. Do you have a 2nd power supply to test?
I tried 2 different PSUs: One with selectable voltages and one 9V 1A. Both react the same way. The 9V 1A one works fine when tested on my TG16.
Usually the most likely is usually what it is, bad connection between hucard and connector,
could also be between connector and board, but that's more rare.
I took a toothbrush to clean off some residue from the connector. I used my magnifying lens to check the pins and they all looked uniform. When a HuCard is inserted, it's pretty tight in there.
if you turn it on and off rapidly does it show something new on screen every time?
bad connections between the hucard and connector usually shows a white picture and the following times turn on fast showing the screen in different colors, green is common, but yours is garbled?
like when hucards are beyond repair, but as they work on other systems it's not them...
When I power on after I first insert a HuCard, I get either a light purple-ish screen, white screen, or the vertical lines on one game. On another, I just get a black screen.
sometimes random things or colors can be seen when one of the main chips are damaged, can you see if it looks like someone tried to region modify it? sometimes when people try to lift legs they don't do a god job, lifting the wrong or leaving small strains of nearly invisible solder to other legs that can short it out either for good or just temporarily depending on what they did.
As far as I see, there is nothing that shows that a region mod has been attempted. The ribbon cable connecting the HuCard slot to the mainboard doesn't seem to be damaged. I inspected the ICs on the mainboard. Some of the pins look oxidized, but upon closer inspection, it looks like something may have spilled inside it.
I already arranged to have a replacement sent. I'd like to tackle this myself, but I am low on the resources to fully go into repair for this.
I appreciate everyone's help in this matter.