Hi Mobus, I have a similar problem if you have a moment ....
I’m having difficulties linking my secondary decoder a 2p PVR HD with the primary decoder a 2A. Currently I have them both directly wired to the dish via a dual LNB (LMX 501) and then the decoders linked to each other via RF out to RF In on the second decoder. I was told that the linking cable should rather be RF out on the secondary decoder and then RF In on the primary, so changed this, but still no joy here ! I have checked all my coaxial cables and plugs with a multi meter and all seem fine. I have also checked with DSTV and the primary account and linking of both decoders is registered. I have read that the primary decoder should rather use socket A and not socket B so can also change this. The secondary decoder is positioned further away from the dish than the primary decoder hence using socket A, as I gather this is stronger. Both decoders seem to be sending heart beats but are evidently not communicating. I understand the 2A has a built in diplexer, but do I need to get one for the 2p decoder ?Any help most appreciated....
As already stated, check that both decoders are receiving an adequate signal on all tuners and both can at least show ch 100.
Next, you DO NOT need diplexers IF you are already linking the decoders via the RF ports with a separate cable for the HB signal.
A Diplexer is only required IF you choose to send the HB signal via SLNB and LNB cabling and then the diplexer is required behind the HD PVR2P to extract the HB signal from the LNB cabling and insert it into one of the RF ports on the HD PVR 2P. The choice of RF OUT or RF IN is dependent on what you are doing with the RF signals from both decoders. If you are NOT distributing RF to other TVs in the house then it does not really matter which ports you use.
It is best practice to use the RF OUT port on the Primary decoder, which in your config should be the Explora 2A, as it has a better power supply than the 2P.
The Primary should be connected to port A on the SLNB LMX 501 as that port is the main power supply port for the SLNB.
Port B should be used to feed signal to the 2P.
The 2P uses as default UBs 0, 1 when set to SATCR Universal. These values can be changed but it is better to leave them on defaults.
The Explora 2A MUST then be set to use either decoder 2 or decoder 2 settings using the installation wizard and NOT the default decoder 1 settings as these will clash with the UBs used by the 2P.
Note that IF there was anything wrong with the installation when MC sent the signals to the decoder for the XV setup, the decoders WILL NOT receive them and then MC MUST redo XV completely from scratch once the decoders are working and installed properly.
Check that the 2A is actually the primary decoders and transmitting HB.
Check that the 2P is set as secondary and RECEIVING HB. it can't be set as transmitting HB.