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Great C&P from tyson01, from another site



Testing your DiSEqC 4x1 switch

Facts about DiSEqC switches:
DiSEqC switches use 1.0 or 2.0 software, there is no difference between the switching commands in these 2 versions, they both use DiSEqC 1.0, so that is what you will use.
DiSEqC 1.1 (uncommitted) is for a special kind of DiSEqC switch, this 4x1 switch costs $70, on sale, so trust me you don't have one of these switches, so you don't need to use DiSEqC 1.0/1.1

DiSEqC switches can be a problem, the majority are made to sell at a low price and the quality control reflects this.
Chieta Heavy Duty switches seems to be the exception this.

DiSEqC switches are also very sensitive to power spikes, when you add or remove a cable from a DiSEqC switch this causes a power spike and this will damage the DiSEqC switch usually the first time it happens, so you don't get a "do over" with these switches.

So ALWAYS unplug ALL receivers from power when servicing a DiSEqC switch, using the ON/OFF switch on the back of the receiver is the same as unplugging it from power, turning off the receiver with the remote or front panel button is NOT the same.

A damaged DiSEqC switch will pass the signal on LNB1 port only, which tricks you into thinking the switch is working, but you can test for this.

Testing a DiSEqC switch, or any switch for that matter, can/should be done inside.

Turn off all receivers, using the switch on the back, unplug any sub boxes connected to the same dish you will be using.

Connect the cable going to your test receiver directly to a working LNB.
Turn receiver back on and select that satellite/LNB then see what your Signal and Quality levels are, write down those two numbers.
(you must have a high signal and quality level to do this test)

Turn receiver off using switch on the back, ALWAYS.

Disconnect the LNB cable from LNB IN port on receiver.
Connect the DiSEqC switch to the LNB IN port on the receiver using a short piece of cable.
Connect the LNB cable to LNB1 port on the switch.

Turn receiver back on and select the same satellite/LNB as before.

Use
DiSEqC 1.0
committed 1 (or port 1)

You should have signal and quality levels matching or just slightly less than before.
If you have no or low signal and quality then either the short cable your using is bad or the switch is.
If the quality drops 20-30 points then switch is bad.
If receiver shuts off on its own then cable or switch has a short, check or use different cable and retest.

If Signal and Quality are ok, then shut off receiver using switch on the back.
Move LNB cable to LNB2 port on the switch.
Turn receiver back on and select same sat/LNB as before

Change setting to
DiSEqC 1.0
committed 2 (or port2)

You should see Signal and Quality come back up, in some models you have to "save changes" before it will send the new DiSEqC switch command.

If you don't get Signal and Quality back then switch is bad, a bad DiSEqC switch will pass a signal on the LNB1 port but not on any of the others.

If Signal and Quality come back, turn off receiver using switch on the back.

Move LNB cable to LNB3 port on DiSEqC switch.
Turn receiver back on.

Change setting to
DiSEqC 1.0
committed 3 (or port3)

Check signal and Quality levels.

Repeat for LNB4 port, shutting off receiver, moving cable and changing settings to

DiSEqC 1.0
committed 4 (or port4)

Once you have tested all your switches, you can move the DiSEqC switch out to the dish(receiver powered off!) and connect all the LNBs up to it.
Then power on the receiver and do your settings to match how YOU connected the LNBs to the switch.
Once you have the settings done, turn all receivers back on and try switching between sats/LNBs if you are still having a problem then you will need to ground all receiver cables to a common ground point, even if you only have 1 receiver you may have to ground the cable.
The cables from the DiSEqC switch to the LNBs can also be the source of grounding issues, loose connectors = intermitant trouble.

DiSEqC switches also don't like cable runs longer than 50ft to the switch, this can often be the source of the problem, using a Chieta DiSEqC switch can solve this problem in most cases