Take a VOM meter and disconnect your tiu from layout and transformer. put ohm meter on continuity and check resistance across input of channel 2 fixed 2 input and read ohm should show infinity or no ohms at all the check 2 fixed output. you should again read infinity or no ohms at all! if either test you read 0.0 ohms you have a dead short across input or output. if the occurs you have a shorted tiu tvs diode across input or output channel. while your at it I would check all tiu input and output channels ! also check out transformer by itself to make sure its not a transformer issue. if you don't find anything wrong when you test your tiu as descried above check your tracks for shorts with the same meter. the reason I had you disconnect tiu was to avoid if it's a track issue or not!
p.s. you can check the internal fuses , but they rarely blow ,but if you choose to you have to take out 6 screws on the bottom of your tiu and then pull the top cover off, the fuses are yellow in color if your tiu does not have any as some versions do not have fuses reg G for instance . most common is rev L and it does have fusses!
Alan
