couple of thoughts to ponder
1). it's unclear, but appears the some receiver can send diseqc commands several times, if you wish.
- is that something you could try ?
2). the 12 or 18 volt DC power has a small 22khz tone impressed on it, with an amplitude of about .6 volts (from memory, see the specs if you care)
So, that means the 12 would vary from 11.7 to 12.3 at the 22khz rate, etc.
3). on MyTheatre forum, they have mods to cheap diseqc switches to handle the lower 22khz tone bursts that Twinhan cards put out.
- real switches don't seem to have a problem with 'em.
- maybe change switches, and see what happens...?
4). here's one I like: if a switch doesn't pass power to inputs which are off, but have other switches (not LNBs) on them, what happens when that switch-port is reselected?
- does the receiver initialize the 2nd level switch properly?
- does the 2nd level switch have time to properly power-up?
- this could be a timing problem with the receiver.
5). I think there are several failure modes to diseqc switches:
a - doesn't pass through the signal
b - doesn't send power to the LNB
c - selects more than one source (but perhaps only one is powered)
d - sends power to more than one LNB, but selects signal from only one
- (c) & (d) seems to be quite insidious.
there isn't a lot of isolation between input ports, so having live LNBs could cause cross-talk.
(I actually read about a cross-talk problem here on the forum - user had two powered LNBs and a diseqc switch)
If all else fails, change the receiver. -
