Hey guy,

Seem to be a dead end on this so I'm posting up here in the lounge hoping that someone has seen this before.

Long story short...

I have a Univeral MRF-350 base station sending signal to an LG 50PC5D plasma tv. It is connected via mono (2 pin) signal cable.

I'm getting no responce from the TV.

I'm hooked up from port 1 on the MRF-350 to the "remote in" on the back of the plasma. I have double checked the cable and tried a different cable. I know the TV see's I'm hooked up because it disables the front IR input when connected. Still.... no control.

I'm just wondering if you guys have seen something that I've missed.

Turn up the IR output of the MRF-350?
LG's pinout different than the norm?
LG using a 1/8" 3 or 4 pin connector for some reason?
Installer menu setting for rear IR control needed?

I know I can always install an emitter but, I would prefer not...

Any suggestions.
Thanks.

Is it assigned to that output in the remote programming?

Yes, it is assigned to that output.

I have reassigned it to a different known working port for troubleshooting. I have also setup the MRF-350 to output everything to all ports just to try to troubleshoot it.

It's almost like the LG 50PC5D set has a faulty IR input.

I was just hoping that I'm overlooking something or LG has a "quirk" that I don't know about. This TV is several years old but, the IR input has never been used before now so I know that it has been over-driven in the past or anything else that could cause a circuit failure.

If this was a client TV I would have given up long ago and just installed an emitter but, this is my TV...

Are you sure it's a mono input? A lot of rear IR are designed for a powered IR receiver so they use a Stereo plug with 1 pin having power and the other 2 signal and ground. Can you get a pin out of the IR from LG?

No, I'm not sure it's a mono input. That's why I'm asking. I don't know what the pinout for a powered ir input (as you suggested) would be.

I can't find any information in LG manual that would indicate otherwise.

The manual states:

1. How to Connect
 Connect your wired remote control to the Remote Control port on the TV.
2. Remote Control IR Codes
 Output waveform
Single pulse, modulated with 37.917KHz signal at 455KHz

That's about it....
The manual has a very complete section on RS-232 control but no much information on the rear input IR control.

???

I know I've run into this on a few devices. Do you have a stereo plug and a multi-meter? You could plug it in and measure the pins to see if you're getting any voltage out.

Is there enough IR level into the LG? I have had issues with RTI default level settings into wired IR ins not working, crank up the level a bit and away it goes.

LG/Zenith does some weird things with their inputs... You have to use an adapter to make it work. I have used this one in the past with success on about 30 or so different LG's.

[Link: audioplex.com]

I'd take rr61522's word for it, because he's seen the problem and seen it solved.

This seems like a similar problem I'm having with my Verizon Fios (MOtorola 7100) HD cable box. I started a thread here asking this question, but this seems a lot like what's happening with me.

Any o you knowledgeable people have any ideas why I can't get the IR Input to play nice with my Harmony 900 RF module?

You need to use the Audioplex piece. They are specked into most of our jobs. No worries of an IR being knocked off by the cleaning lady.

It seems the audioplex converter solved the problem....
I had on loaned to me that I tried out and it worked great.

Rather than drop $100, I'm just going to pop the back off and embed an emitter. On the other hand, it is good to know I wasn't going crazy (yet...).

Thanks for the input guys. No matter how long I've been doing this stuff; I still learn something new everyday.

I believe the reason for this is that some new engineer, who doesn't know how things have been done for years and years, and more importantly WHY they've been done that way, invents a new and less friendly way to do things.

Frinstance, before discrete IR commands, you could always make a TV input macro by starting with channel up. I always figured the logic was, if you're trying to raise the channel, then obviously you don't want to be on a video input so we (the TV) should switch yo to the TV tuner. About eight years ago someone at Samsung decided it was more appropriate to put up a message saying something like "that function does not work in this mode." And no, the TV did not have discrete commands!

Just was given a LG 50pc3 plasma because front IR receiver would not work. It seems these plasmas have an issue that if the rear IR input gets dirty with dust the front IR receiver is turned off because the set thinks their is something installed in rear. The fix is electronics cleaner sprayed into the rear IR hole and using a plug, plug it in and out a few times.

Charlieg,
You are correct on that, once the LG senses a contact on the rear "remote in" the front IR receiver turns off.

Ernie,
A agree. I think the engineers at LG are nuts. I was recently installing (qt. 280) 32" commercial/hospitality LG sets. We wanted to hook them up to the surround receivers in the upscale hotel rooms. The sets had two audio outs. One optical and one 1/8" stereo. We hooked up to the analog out only to find out we had lip sync/timing issues. I contacted LG directly and spoke to one of their engineers for about a half hour. They told me that the 1/8" anolog, line level output was only designed to interface with a proprietary "bathroom speaker". The only solution was to use the optical output. Being that the AVRs didn't have optical inputs, we were out of luck.

Who ever heard of a rear audio jack that was intentionally out of timing?

What the hell... Shame on you LG.