How to solve problem with DiSEQc switch?

[Wim]

Vu+ DUO
Devicename: dm8000
Enigma Version: OpenPLi 2010-08-17-master
Image Version: openpli-2010-05-21
Frontprozessor Version: VNone
Webinterface Version: 1.6.2

I have a problem receiving the Thaicom 2-5 Sat, Ku-band and C-band using a DiSEQc between two dishes. I believe the switch is broken or the switch does not receive a signal to switch. This because most of the signal is lost over the cable(25/30 meters) or the box does not generate a signal. This because I do not configure correctly or the box does not generate a signal indeed?

Configuration: One dish with Ku-LNB, One dish with C-LNB, One cable running to Receiver box.

Dish- C connected to DiSEQc input 1, Dish- Ku connected to input 2
Tuner A configured for C-band on input 1 (AA), Manual scan: receive all C-channels
Tuner A configured for Ku-band on input 2 (AB), Manual scan: no Ku-channels

Dish-C connected to DiSEQc input 2, Dish-Ku connected to input 1.
Tuner A configured for Ku-band (AA), Manual scan: all Ku channels
Tuner A configured for C-band (AB), Manual scan: no C-channels

Since the DiSEQc is a normally closed switch over input 1, this input will always work, which is the case. Input 2 does not generate any signal. I have tried 3 different switches:
Infosat 4x1 model DSS4101, Novakova 2x1 and Spaun SUR 211F. (Spaun is a non-committed switch so I configured accordingly.) All with the same result.
I have attached some screenshots of the receiver settings
Since I tried 3 different switches I assume the switch is not at fault. Than the only reason could be that the switching signal is too low or none at all. This could be because a long cable or faulty or wrongly programmed box.

Anyone can give me a suggestion how to find out what is realy the problem?

[Hakon]

What type off LNB for the Ku band ? Universal ? I see in your setting for the Ku LNB you have choosed "User defined" setting, but it think you know what you are doing here. Have you tried to connect the LNB direct to tuner without the switch ? Have you tested both tuner in the Vu+ ?
If your Ku LNB is a standard universal LNB you can go for the Simple settings for Tuner config, just to see if the input 2 at the DiSEqC switch work.
You can also test the input 3 or 4 in the 4/1 switch in this way , Simple settings A/B/C/D.
It sounds very odd that all switches are broken .The SPAUN is the best of these you have.

You are correct that port A in a switch is always active as long it dosen't get a DiSEqC signal.

[Wim]

Thank you Hakon for your effort to reply.
I have tested the Ku-dish with its LNB and these settings without a DiSEQc. I need to configure the tuner in advances mode since in Asia the LNB needs different settings. Result: I received all the channels I expected.
I have tested the C-dish with its LNB and these settings (C band) without a DiSEQc. Result: I received the channels I expected.
As you can see, my next test was to test with the DiSEQc. It seems that I cannot get AB, or input 2, to work. The SPAUN is indeed the best, the only non-committed switch in my set up, but that is why I have the current set-up still with the SPAUN. I realy start to question if the box does create the signal for switching? Any idea how I can test for that?
By the way, I have not tested the other tuner yet, could that make a difference?
Thanks again.

[amires]

Well you mentioned your cable run is 25-30m. It is not really that long unless you are using low quality cables. What kind of cable are you using?

[Wim]

I must say: Thai quality.
Here you can expect everything but I am not able to specify the cable. I have been "told"good quality.
On the other side, I am locked to Thaicom 2/5 and Sr ratio is 79-81 %

[Hakon]

If you choose in advanced mode DiSEqC 1.0 you have still the same settings for you LNB, it can be worth a try.I am a bit lost here with the Asian settings, cant understand why not universal in settings but i like to learn.

[Wim]

The text below is copied from the PLi@Wiki. It explains the LNB LOF settings. It works as it has been described.
It will not solve my problem with the DiSEQc though and I am at a loss now. By the way, I have now tried tuner B, does not make a difference.

4g. LNB: LOF Now this is an important one! This setting is asking for the details of your LNB.
the options are;
•Universal LNB = the same world over (09750 - 10600 - 11700)
•C-Band = the same world over (05150-05150-03200)
•User Defined = CHANGES in every country (normally a Ku Single or localized Ku Universal LNB)

Examples of User Defined LNB's
•USA LOF/L = 09750 - LOF/H = 11250 - Threshold = 11700
•Australia LOF/L = 10700 - LOF/H = 10700 - Threshold = 12000
•Asia LOF/L = 11300 - LOF/H = 11300 - Threshold = 12000

[Hakon]

My last idea, check the coax and the connections , specially the shield. It has happen before that one small wire of the shield has connection with the inner conductor.