In the past there have been questions about IR repeaters, and I've talked about the Radio Shack 15-1959 units, which are essentially a rebadged "Terk Powermid" set.

I've owned two sets of these, and the second set just went bad. Bad in the sense of, the receiver unit stops responding to the sender unit, and seems to emit a steady stream of random IR when plugged in. Both sets worked great for years and then one day just stopped working.

I find it strange I've had two sets go bad on me. Anyone have any clue as to what might cause that to happen to these things over time? Anyone else own a pair of these that went bad?

I know you're asking what might be going wrong here, I don't know but here's my experiences with Powermid's:

First set DOA: The pair of units were very quirky, they'd relay some remotes ok but others never. Then, almost at random, they'd relay nothing at all. In either case, the LED on the transmitter usually flashed but the flashing pattern looked very different to the LED on the sending remote control. My guess is they weren't both tuned-in to the same RF, or at least, they were only marginally tuned-in to one another.

Replacement set: Fine for a few years then the IR transmitter would start blinking its LED like crazy (like yours it seems) and remote IR control was unreliable. Turning off the transmitter made no difference. I suspect that it was picking up RF interference.

I've moved house recently and I never bothered to figure out the last problem, the family viewing habits had changed and we just stopped using the Powermids. This has got me wondering now; there were cell phone transmitter upgrades in my area at around that time, I wonder whether the transmitters, albeit on a completely different frequency, were messing with the Powermid? In RF terms, I'd always regarded them as being fairly rough-and-ready and I doubt whether they are at all selective about what they receive/relay.

Popping the top off and looking at what's inside, I see two potential points of failure...

1. The RF receiver/transmitters, like you said, might have drifted off frequency. I've got no idea how to retune them.

2. They both have a complete DC power supply transformer inside the housing, and I've seen my share of cheap DC power supplies go bad with age.

Mine do this occasionally. It seems to be interference in my case. I move it a few inches until it stops. I've been using all 4 of mine for 7 years now with no issues other than tht at all. Good luck perhaps.