I have an issue with a system that was working fine for the past year, but is now having issues with IR signals not always being recognized. It is either the MRF-350 or MX-780 going bad. I suspect it is the MRF but would hate to replace it only to find that it was the remote that was having issues.

Because the remote talks RF to the MRF-350 it seems like it would have to be a problem with the MRF-350 repeating the IR signal. I don't see the interference light on and it does not seem to be an interference problem.

Has anyone had a MRF-350 just go bad? Anything I should do to double check the device. Adjusting the intensity of the IR on the unit sometimes gets it back to working, but then will fall off a few days later being un-reliable again.

Just to make it a little more clear on what looks like is happening. It looks like either the IR emitters are fluxing to either be too loud or too soft (adjusting the intensity, even back to the same setting, seems to fix it temporarily) or that they are sending garbled codes. For example I had a pioneer AV that was using a direct mono-IR input cable, but it stopped working and I couldn't find an intensity setting that would work any more, and had to switch back to using an IR flasher.

Where is the placement of the mrf350 and the rfx250?

What is the connection of the rfx to mrf (wire, termination)?

Shallowearth,

It is possible that the MRF350's output level potentiometers are oxidizing. You can often break through this oxide coating by rotating the control over its full range a dozen (or two or three) times.

Joe, they are in an open face cabinet about one foot from each other, using the cable that comes with the kit.

Buzz the oxidation sounds like a real possibility, as the blaster I am using for an Xbox stopped working and does seem to crank high enough any more.

I'll try cranking the intensity screws but if they are oxidizing, and we are here in the humid northwest, I am guessing a new unit is in order.

Shallowearth,

Oxidized surfaces is a standard midlife crisis for potentiometers. There are chemical treatments, but you would need to disassemble the unit in order to properly apply the treatment. My experience has been that well over 90% of the chemical treatments are effective for a year or two or three, then you need to repeat the process. I've been less successful treating the tiny potentiometers like those in your unit. The rotate a bunch trick above is at least as effective as the chemical treatment for these little controls. If you decide to use the chemical -- a tiny, tiny drop is all that is required, don't flood the place.

Well, I just tried the turn it back and forth method, and there was definitely some scraping and crunching, so I am going to assume the oxidation was the problem. Not sure why this one was so problematic. Maybe it was old stock, or an unmarked refurb or something, I have several MRF260s that have never had this problem and been working faithfully for many years. This MRF350 only lasted 18month before starting to have a problem.

I've cleaned hundreds and hundreds of volume, bass, treble, and balance controls in my repair days.

I've not seen oxidized pots in a single MRF device in 15 years.

Move the antenna around, in particular, as far from cable boxes as you can possible get. Intermittent interference is going to be your issue - my guess.

Shallowearth,

Of course, it is possible that you accidentally reoriented the antenna to a more favorable spot as you fussed with the control.

Didn't move the antenna, but I will definitely do that as well, it is fairly close to the cable box.

I haven't had a MRF 350 that makes scraping sounds when you adjust the emitters either so something is amiss here, and still not as snappy as other systems I have setup, haven't fully tested everything yet.