TIU Fixed 1 no output

hi you might have a shorted tvs diode on the out out side take cover off and check 4 diodes there is one on each channel output, disconnect one end and check continuity if 0 ohms diode is shorted and needs replaced, your track short frequently causes  these diodes to short! if you disconcert and find the shorted one while disconnected power up and you'll probably find tiu now works, you don't want to operate it like this but is ok for a test! if you need repaired let me know!

Alan

I thought when a TVS shorts, it is exactly that: a short across red and black. That should trip an overload protection. He has an open circuit.

I recall from a past post that the fuses (in TIUs with fuses) are between the In and Out BLACK posts. I think these fuses were added to protect the traces on the circuit board. You may have a fried trace if you have a TIU without fuses.

It's very likely that you have lost channel #1 for good.  The original (Rev. G) TIU has no fuses and undersized traces for the pass-thru.  I suspect if you remove the PCB on the bottom you'll see an outline of a cooked internal trace.  There is no fix for that.

Thank you for the responses. The internal trace issue is what I read about. At least I can work around it for now.

I see plenty of TIU that the terminal melts and insulates the connector from good contact on the input terminal.  Of course First TIU had a solder joint not, nut and thread connection.  BUt for later models, make sure terminal nuts inside the TIU are tight.  Any signs of melting plastic means a high resistance point.  G

Since this is a Rev. G (no label), I suspect loose nuts aren't the issue.  I have two of these in my closet with the cooked trace, I'm sure there are other examples floating around.

That is what I said, but to let others know with later TIU to keep terminal nuts tight.  Plus you can have the solder joint detach on G version.  Heck I have seen motor diodes desolder from heat on PS-1 and DCRU boards. G