@GGG posted:The simplest is when one channel does not work but all the others do. The worst is none work and LED barely lights or the current draw is high just TIU. This means a short that is effecting the Power Supply. So you can pull all the transmit chips and if still present pull the receiver. If still shorting change the 5V reg, if still shorted, look for round object with lid and deposit TIU in the object.
Yep, this is what inspired me to work on 2 TIUs in the pile that were totally dead. One came back to life, the other is a parts donor. Thanks for this tip as I incorrectly assumed everything was fried (meaning the logic too) and this inspired me to just remove them all (all 4 TX and the RX, and even the 5V reg) before deciding dead or not. That point where you have nothing to lose, it was on the left for dead shelf.