Disclaimer: This will be lengthy, my apologies
I've got a Hughes GXCEBOT DirecTiVo box with two tuners, purchased over a decade ago, and it's been in constant use since then. The only changes I've made to it from stock was to put a bigger HD in it way back just after purchase.
Back in the day, I had an oval dish with a dual-LNB output connected to the unit. But a couple of years ago, I got an HD set for one room, and DTV put an H24 in for it. They changed out the dish at that time and installed an oval dish. It's got a single LNB device on it, with four cables coming from it into the house. Three of those cables are used. One to the HD box, and two to the Hughes DirecTiVo.
About two weeks ago, I started having problems with the Hughes box. I'd wake up in the morning and find the system "searching for Satellite signal" on both tuners. I was able to "fix" the issue the first time with a reboot. It happened again a couple of days later, and that time it took two reboots to fix. Another day or so passed and the problem returned. This time no amount of reboots fixed the problem, so I set about to seeing if my cables were good.
In the course of troubleshooting, I found that if I switched around the cables at the grounding block, I could get a signal on one of the tuners. As it was getting late, I left the unit running overnight with just one tuner. The following day, I swapped the cables around on the grounding block some more, and was able to get both tuners up and running, with the HD system unaffected. However, I noted that if I pulled the power from the HD box, or disconnected the Sat cable running to it, I'd lose signal on both tuners of the Hughes SD box.
Very odd, so I thought I was having an LNB problem. I called DTV and for $50 bucks, they sent out a tech who swapped out the LNB. Well, since I'm posting here, you all already know that the problem wasn't fixed. In fact, I haven't been able to get both tuners back up and running. I can get one tuner going at a time (doesn't matter which), but as soon as the other one is connected, both are dead in the water. The HD set remains unaffected, but still has the oddity that if I power it down, or disconnect it, I won't get anything on either tuner of the Hughes.
As for signal strength, it's fine by all measurements, and all cables test fine, so that's not the issue. However, if I look at the signal strength via the Hughes box, I'll see one of two things happening. Either the signal is there, and then it's not (alternating about once a second), or the signal is just plain missing from a set of transponders. Currently, I can get good signal on all the odd transponders, but zero signal (as seen by the Hughes box) on all the even transponders.
As part of the troubleshooting, the tech installed a multi-switch (unpowered) to see if that would help. It didn't. The multi-switch was removed.
As a last resort, the tech brought in an R16 box (which I was told was the equiv box, but DTV software, not TiVo), and hooked it up in place of the Hughes. The signal seen by the R16 looked right on the various transponders. (didn't seen real TV, because that would have required an activated card).
So, it seems that the problem is with my Hughes box. But what could it be?
Bother tuners work just fine on their own, and I was able to get the both working together up until the DTV tech replaced the LNB (although I haven't yet gone through all the combinations of switching cables around).
At the moment, I've set the Hughes box to use just one tuner, and it's working fine as-is, but I'd like to get the 2nd tuner back up and running. Remember, both tuners work fine on their own, just can't get them working together.
So, any ideas? I know there had been problems with caps in the past, but this doesn't seem to be the same problem. (or is it?)
Any ideas are appreciated. ...and thanks for reading this far. I know it was long-winded.