This listing is for the somewhat hard to come by Modbo 4 that's running on Matrix Infinity 1.93.
The Modbo chips are clones of the old Matrix Infinity chips. The last firmware that was officially released was 1.93.
Most of the Modbo 4s you find these days are running on 1.99 which is a modified version of the firmware known to cause issues.
Modbo 5s claim to be running on 1.93 but are also a hacked version of the original firmware.
In my Experience, the Modbo 4s running on 1.93 have been the most consistent chips that I've ever worked with.
For install Diagrams, I'd recommend going to Quade's site HERE as he's compiled multiple diagrams for every model of Ps2 console