After a powercut / surge this Joytech component switcher decided to died along the the OG Xbox that was plugged into it. 

Stripdown of the unit

Stripping down the unit was fairly straight forward. Everything looked fine and there was no immediate problem visually. The investigation started with caps, voltages and finding shorts, none of which seemed to be an issue.

Faulty chips and testing

After running out of ideas I decided to remove some of the logic chips and test them in the TL866 programmer. Turns out all the CD4051 chips were all internally shorted. Swapped some new chips on to the board and everything was back to normal. A fairly easy fix one I found the issue.