can't adjust polarity on 4dtv receiver

[amvan123]

I just installed the GI 4dtv receiver on a 10 foot dish. It took a while for me to get it lined up because i guess i am old and senile. I finally got to the point where x4 showed up and loaded the channels and got the DC light to come on. I called skyvision and got hit and trip counter went up. Now only some of the station come in. I found the polarity was not changing. Now even when i go to adjust satellite and manually change polarity, on the dish it does not change the location of the Polarotor. I hooked up an other Polarotor to the receiver and it did not work either. I believe that the rotor was working at first but not sure. Do I have to go to adjust IF freq. for both horz and vert feeds, i just did it on one to get the channels to load to x4. Is there a way to put external voltage to the Polarotor to change it angle? Could i have changed something inadvertently to make it not send pulsed to Polarotor?
Thanks for any info you can give me

 

[waylew]

Check to see if it is set to operate a polarotor.
Press, OPTIONS/6,4,2,line 2,LNB type should be set for C and/or KU LNBs,NOT LNBFs.
Line 4,Feedhorn Polarization,should be set for Standard.

 

[amvan123]

Thanks for your response. I did check to see and it is set to c/ku, i also tried c only and c with not polar just to see if it would reset something, then went back to c/ku. the polarization is set to standard, even changed that to see if it would make any difference

 

[amvan123]

More info,
I checked the 5 volt connection on the receiver and it is not there. Even when i change polarity. So i think something is wrong in the receiver.

 

[waylew]

Okay,the main thing is to make sure it's set for "lnb",not"lnbF".
If you have a spare polarotor motor,try hooking it directly to the back of the receiver,disconnect the polarity wires running out to the dish first.And just to make sure it's,red+5v,white is pulse and black is ground.
Also remember that polarity doesn't always change on odd to even channels when using digital (virtual) channel numbers.Use channels 1 and 2,or any odd/even combination between 1 to 24,to check for polarity change.

 

[amvan123]

Ok Waylew, thanks for your response. I did hook up a brand new polaroter directly to the back of the receiver and no movement. I also measured the voltage on the red 5 volt terminal on the back of the receiver and has 0 volt, even when you change the skew. It is set to lnb, not lnbf. My next thought is to try to use an external 5volt source. Do you think that would be beneficial? Do you think a master reset would help. It was quite a job to get the receiver up to date so that would be my last resort i think. I was also thinking of taking the 5volt of an other location in the receiver.

Does anyone know where i can get service information on the 4dtv receiver? I use to own a electronic repair shop but troubleshooting is a lot easier with a schematic.

thanks

 

[FaT Air]

I'd think they'd use a PTC fuse (polyfuse) Try disconnecting the servo, unplug for a minute, then plug back in. Adjust skew with a voltmeter on the +5v terminal.
Think you're, and everyone else, is out of luck for a service manual of any sort. Don't think the big M gave any out.
I know a lot of IRD's BITD would only supply the 5v for a few seconds to change/adjust skew, then remove it for 'no (servo) chatter'.
Put a 'needle' type Voltmeter on the pulse terminal. If some reading the pulses are there. Could try supplying 5v to the servo?? Common the negative GND.

 

[waylew]

Do not do a master reset,you will lose almost everything (and most likely would not fix your problem) and won't be able to get it back,unless,you buy the usb cable and get the Mapmaster program.See the "stickys" in this section for more info on Mapmaster.
I'm pretty sure the 5v is intermittent as FaT said and there is no service available,that I know of.You could try Googling to see if anyone had the same problem and posted a fix for it.
I'd try tracing back the circuit,old school/hard way,to see if you can find the problem and fix it,before trying a different 5v source.
Another option would be to swap out the polarotor for an LNBF and just use voltage switching for the polarity.

 

[amvan123]

thanks for the info waylew. I will try to see about tracing the circuit. I had read else ware that the lnbf were not very good but it was an old post from years ago and was thinking that they had gotten better by now. I will let you guy know what i find out

 

[FaT Air]

The new PLL LNBF's are good. So are many DRO types. Might find the PLL's do better on low SR's than DRO. Don't let a low 'noise figure' fool you.

 

[amvan123]

Thanks fat air,

Do you know anything about company called galaxy marketing? This is the lnbf i was thinking about,
http://www.galaxy-marketing.com/741-standard-cku-c-and-ku-digital-lnb-lnbf-linear-circular.htm
Do you think there is a better choice?
I appreciate your assistance.

 

[amvan123]

oh hi, here is an other one i found that might be better
http://www.ebay.com/itm/C1-PLL-C-ba...ellite_LNB_Downconverters&hash=item3f2e7b7f62

 

[amvan123]

here is an other one i found that might be better:
[h=1]C1-PLL C-band Phase-Locked Loop LNBF FTA PLL LNB[/h][h=2]Titanium Satellite FTA PLL LNB[/h]

 

[FaT Air]

Think you'll be plenty happy with the ( (C band only) C1-PLL. There's a thread or two containing a lot of praise.
The 741 may also be acceptable. But the dual band LNBF's are somewhat of a trade off in performance. Lose a bit of C band performance to accommodate Ku. Takes very careful 'tweaking/tuning' of the LNBF.
Guess it's all up to 'personal preference'.

 

[amvan123]

OK I have ordered the c1-ppl. It will probably be here in a week or so. I will check back in and report on progress then.
Thanks

 

[waylew]

When you get/install it,remember to set the 4D to Cband LNBF and rotated 90 degrees.

 

[amvan123]

ok thanks waylew. that will be in about a week, hope i can remember that long....lol Also looks like we have some bad weather coming in so may be delayed on the installation. will let you all know what happens.

 

[amvan123]

ok, I just got my new lnbf but in the mean time i got the thing going. I found a p3 plug that had 5.7 volts on pin 1 (first pin from the front). I took a three and a half inch floppy drive plug from old power supply and slipped it over the pins coming off the circuit board. Took pin 1 and ran it to the 5 volt wire going to the polaroter and it seems to be working.
I tried the 5 volt going to the actuator but it must not have enough current to run the rotor as it dropped the voltage to about 2.73 volts. Not sure if i will put in the new lnbf or just use it like it is.