Odd transponders out on DSR units, works on HR-20

[blunck2]

I have a strange problem I'd like to describe and hopefully somebody has some advice for troubleshooting.

I have 2 Philips DSR-724 series "DirecTiVo Series 2" units.

I also have a DirecTV HR-20 HD receiver.

I have an AT-9 dish along with the unpowered 5x8 MultiSwitch that everyone on here recommends (I can't remember it's name and I'm too lazy to go look at it downstairs in my basement ).

Everything has been running just swimmingly for months.

Now I'm getting "no signal" on one of my DirecTiVos for odd numbered transponders on all satellites. I get perfect (mid 90s) signal on the even transponders. Every now and then I'll get a great signal on an odd transponder but it will disappear after a few seconds. Sometimes it comes back. Often it doesn't.

The strange thing is that my HR-20 reports strong signal (mid 90s) on both even and odd transponders on all satellites.

And my second DirecTiVo reports very spikey signals on the odd transponders (40, 95, 70, 50, 80, 90) very rapidly. It's bouncing around all over the place!

Nothing has changed except for a software update to the HR-20 a couple of nights ago. That kind of corresponds to when this started happening but I have a hard time convincing myself the two things are related (although I won't rule it out).

I'm going to check my dish tomorrow morning for any signs of corrosion between the LNB and the 4 coax wires, but I don't think I'll find any.

Does anyone have any advice for additional troubleshooting?

I've tried powering down ALL 3 units and then powering up JUST ONE DirecTiVo unit and running a signal test. I get the same behavior (no signal on odd transponders).

Any ideas?

 

[boba]

With an AT-9 dish your multiswitch should be a WB68 check that out first to be sure you have the right switch.
Bypass the multiswitch and connect the lines coming from the dish directly to the TiVo receiver and see if the problem goes away.

 

[blunck2]

Figured it out. I direct connected a DirecTiVO to each of my 4 lines from the dish and realized that 1 of the 4 wires was not giving any signal on odd transponders.

I then went out to the dish and located said wire and tightened it's connection to the LNB. I used shrink-wrap tape when I originally installed the connection and I figured that would keep it all snug and secure. It was a real challenge to unravel that shrink wrap tape but when I did I was able to slightly tighten the connection and everything cleared up.