I should have said it can wreak havoc on hight speed digital circuits.
With the RC circuit you propose, this will effectively hold the jtag in reset for the first few nanoseconds or however long.. Its been a while since I read into the hack so you will have to excuse my ignorance.. Is this desirable? At what time after power up is the jtag actually used to deliver the hack? So the reset state of the jtag will not effect the rest of the system?
I think I get it.
Anyway regarding my problem, what leads me to think it is related to the jtag modifications is because i have had strange ROL behaviour, 2 red lights diagonally from each other, while the xbox still boots normally, followed by a 3rrod with 0021 (which I believe is a southbridge error) after a reset. Then after leaving it unplugged for a few minutes it would boot fine..
This all has only happened over the last month, a couple of weeks apart.
I shot a video of the 2ROL once http://xboxdoc.com/yaywoop/2rol.mp4
last night I applied the transistor-jtag hack, using the AUD_CLAMP wiring (previously had the original diode wiring)
I soldered in a chip socket so it'l be easy to experiment without taking the board out. http://xboxdoc.com/yaywoop/jtagtrans.JPG
Although this isnt going to be very scientific because by reassembling my xbox (I had a hybrid-fix installed as a preventative measure) and changing the screw tightness I may have fixed any physical gpu problems.