Problem with XP9303 and r770s

[Hivelocity]

I recently purchased an XP9303 and r770s combo pack.

The receiver didn't work and seemed DOA. I spoke to JR/Horizon and they suggest I send it in.

I sent it back to Horizon and they tested however they said no problem found and it worked fine.

I have been usng a few FM receivers with the same radio - Berg7P and also a HiTech and they both work fine.

I have ensured the radio is in PCM mode when trying the R770S and PPM mode when using the others. Also the same crystal was used.

My question is should the receiver do anything at all when it doesn't get a signal from a servo? Because when I have it plugged in, without my radio on, there doesn't seem to be any type of servo action like you see on my other receivers. A test servo doesn't even seem to have power as you can move it like it doesn't have power.

I guess I want to know if anybody has ever seen a problem with a radio where it would work in PPM mode but would not work in PCM.

I am going to try to find somebody with a similar setup and see if I can narrow down what the problem is. JR told me that their only idea was for me to send in everything and see what they can figure out. They also indicated they have never seen a radio that worked with PPM(FM) but not pcm.

I guess I am kind of frustrated because I just bought this stuff brand new and am having these issues. I also was initially told that when I sent the receiver in it would be in and out in 2 days, only to find out later it was more like 10 days after they get it before anybody even looks at it.

So if anybody has any suggestions or have had similar experiences I would appreciate the info.

Thanks

[Hivelocity]

Figured out the problem - it was the crystal in the radio.

I was finally able to get to a LHS that had some JR gear and was able to troubleshoot.


The crystal worked fine with an FM receiver. However it would not work with a PCM.

I suspected this, and actually hoped this was the problem, as it made life much more simple.

Once i installed a new crystal in the radio, the receiver came to life.

I just wanted to let everyone know the solution.

JR said they had never seen a crystal do this, as it would either work or not. Now hopefully if anybody ever has this issue, they won't go through sending the receiver in etc. I even went to a LHS b4 i mailed in, but they didn't have a JR crystal set to test.

So if anybody ever has a similar problem, this is a possible solution.