"Lnb power failure”.

[Umraneem]

1. I have a smallear ST6600 mpeg2 dvb sat receiver. with Fanchiou ku standard lnb, I use this setup to watch channel on telestar 5
2. The problem started by having the following message “Lnb power failure”. And the signal dies.
3. I changed the lnb to Fortec star universal lnb, and change the setup in the receiver accordingly but the problem is still there.
5. I figure out that this problem is whenever the receiver is in vertical polarization.
6. I measured the lnb voltage and it 15.55 VDC if the polarization is vertical and 21.9 VDC if the polarization is horizontal
6. I change 12146 ghz transponder from vertical to horizontal and it works fine for one day then it stop picking any signal

What went wrong?

[bobkat]

Sounds like a problem in the receiver. The other thing to check is for a bad cable or connector; maybe an intermittent short. Try replacing the cable and connectors.

kat

[syz]

I had the same problem on ST6600 a week ago. It caused by bad cable connecting. When LNB power outside of the receiver is short, LNB power will be cut off automatically for protecting the receiver. Check your cable connection between the receiver and LNBF.

[Umraneem]

I replaced the cable, no luck...
where can I take the receiver to be fixed, how much it will cost?


thanks to all

[bobkat]

Hmmmm...

Sounds like a problem I had with a Coship receiver. It would overheat and the signal would gradually drop to zero. I finally had to sit it sideways to prevent it from overheating. What a piece of crap... :roll:

Try making sure your receiver is well ventilated -- and no other components placed on top of it.

kat

[Umraneem]

yaah it looks to have yjr symptoms, it works fine for 5 mins and then the problem starts!!!!!!! I tried moved it away, although it was on good location for the last 4 yrs, but also no luck......


Thanks

[xiaoda]

Yep, same receiver, same problem.
The receiver is detecting the overvolt (22.9) and shuts down LNB power.
It happens even if I specify no lnb power (slave). It's an internal
power circuitry fault
I posted this over at satforums:


My ST6600 is randomly failing with "LNB Power Failure" popup banners and "HELP" on the display. This receiver was used as a slave to a c-band system. Since LNB power was supplied through the c-band receiver, it wasn't really a problem (just very annoying). But recenlty I tried connecting the ST6600 to a 13/18v LNBF and it could only pull in Horizontal channels, and not for long. When the dreaded "LNB Power Failure" hit, no siginal.

So I checked the LNB voltages. 13v measured close to 17v, and 18v was up around 24v. When the "LNB Power Failure" message displayed, the voltage went to 0.

Opening up the unit, I found a single POT. Buy adjusting it, the LNB voltage varied slightly. I could get the lnb voltage down to ~14.5v but no less. Still that was good enough to pull in vertical channels. However, in doing this, the horizontal channels wouldnt tune in, the LNB voltage only increased ~1v.

Im starting to wonder whether capacitors are the culprit. There are no visible signs of bulging caps in my unit, but power regulation is definately a problem.

Are there other cases of ST6600/7700/8800/9900 failures related to power? Will changing out capacitors (or some some other faulty component) help?

Best I can tell, the ST6600 is a Funtach FD986
http://www.funtach.com/fd986.htm
No schematics there however.