A while back on the groups there was a post from someone that claimed to have reverse engineered the Rev H board and had made up schematics of it in an attempt to duplicate/improve a new board. The posts dead ended however... Did that user's schematics ever come to light??
I have a large pile of boards i have been working through repairing, most of them are just blown FET's for the fans, heaters, and a few with blown digipots for the stepper drivers, i have fixed all them by just replacing parts, but i have a few that have really random odd things wrong that i wanted to dig into a bit deeper and chase whats going on with them.
After fixing two dozen boards now i have pinouts for all the connectors nailed down, and most of the components, but the 5v rail is still a bit of a mystery trying to trace it out so i want to know how the 5v regulation works on this board and chase down the I/O lines for the button inputs from the front panel, i've fixed a couple dozen front interface boards as well but i have some button boards that don't function on even a known good interface board, the only thing i can see is a small IC on the back of the button board that i can't identify, and it appears to be that IC causing the issue as i can remove that component from a working button board and place it on one of the dead ones then that button board works again, so i need to identify that component as well!
Also, shameless plug, if anyone is looking for Rev H boards, i got a pile of them, all repaired, tested, and 100% working, selling them one at a time on eBay. Buying this large batch of dead boards and working through repairing them was just my way to learn the Rev H board, i kept a half dozen for myself as spares... LOL
I also have repaired and tested interface boards, some spare LCD modules, and some spare button boards. If i can ID the component on the back of the button boards i have another half dozen i can fix.