# LNB Drift



## MikeHou (Oct 18, 2006)

I posted in the L449 bug thread about how I'm suddenly missing many channels in my guide and it appears as if I'm now on an HD-only package + locals (I'm signed up for AT250 + locals + HBO, pulling from 110, 119 and 129 on Dish 1000 with VIP622 since August 2006).

Well late last night I noticed the LNB drift detected message. Here's what the system info details screen shows:

Status: Check "Details" for LNB!
LNB Drift Detected...
0x0d, 0xa1, 129(e -7)

It seems to indicate the 129 LNB is the problem, though I was watching the Astros in HD on FSN last night, and that comes in on 129, so I'm puzzled.

So before I go into CSR hell, I thought I would find out what I can do myself. I still have the old Dish 500 with 2 lnbs that they took down when I upgraded to vip622, so I'm wondering if I can try replacing the drifted LNB with one of the LNBs from the old dish.

Is this easy enough to try? I added a 322 to this dish over a year ago, so I have some "experience" messing with it.

Which LNB is 129? Are they labeled?

Any other suggestions would be greatly appreciated.


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## lujan (Feb 10, 2004)

All I know is when I got the "LNB Drift Detected", the E* technician changed out both the LNB's on the two dishes I have just to make sure. I don't know if he could tell which one was bad, so he just changed out both of them.

I was getting missed recordings and missing guide data before he did this.


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## MikeHou (Oct 18, 2006)

lujan said:


> All I know is when I got the "LNB Drift Detected", the E* technician changed out both the LNB's on the two dishes I have just to make sure. I don't know if he could tell which one was bad, so he just changed out both of them.
> 
> I was getting missed recordings and missing guide data before he did this.


What was the out of pocket cost for you on this? Were you on DHPP? Leased receiver? How long has your receiver been installed?

Thinking I'll just enroll in DHPP and give them a call.


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## MikeHou (Oct 18, 2006)

Called for tech support, and I must say it was the least painful support call I've ever had with E*. They are sending somebody out Saturday to replace all the LNBs, no charge.

Lujan, thanks for the input on my problem.


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## euro_boy (Jun 20, 2005)

It was even less painfull for my parents.
The Dish contacted them (they did not call to report this) stating that they are aware that there is a problem with my parents' system. Dish has scheduled a service for them and all LNB's were replaced (500 and 300 for 61.5). I guess this is one of the statistics that 722 is reporting back to Dish.


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## lujan (Feb 10, 2004)

MikeHou said:


> Called for tech support, and I must say it was the least painful support call I've ever had with E*. They are sending somebody out Saturday to replace all the LNBs, no charge.
> 
> Lujan, thanks for the input on my problem.


When I called, they wanted to charge $50.00 until I threatened to stop service. Then all of a sudden, it was free.


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## Michael P (Oct 27, 2004)

> I still have the old Dish 500 with 2 lnbs that they took down when I upgraded to vip622


 It depends on what the old LNB's are - if they are "legacy" then no, you would not want to use them. OTOH if they are "dpp" they I'd try them. They probably are not dpp, otherwise why would they give you new LNB's? Perhaps they are dp. If it's for 129 you may be able to use a dp. that is what I have, a dpp twin for 110/119 and a dp for 61.5.


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## MikeHou (Oct 18, 2006)

As expected the Dish tech didn't show up till 10 minutes after his window, and since we had to leave right then, I've rescheduled for Wednesday

I have another question though. I also have a 322 that is not having any problems, and picks up all the SD channels I'm missing on the 622. Why is that? Does it point to a problem with the 622 rather than the LNB? Maybe a cable issue?

Guess I'll learn more Wednesday, but just wanted to see what I could learn in the meantime.


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## liferules (Aug 14, 2005)

Is there any way to fix LNB drift other than to change the LNB? I called tech support from work and got a level I operator who was fumbling around looking for his script for LNB drift. He seemed adamant that I call from home when I can access the dish screen. Is there actually something you can do to fix this from home?


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## MikeHou (Oct 18, 2006)

liferules said:


> Is there any way to fix LNB drift other than to change the LNB? I called tech support from work and got a level I operator who was fumbling around looking for his script for LNB drift. He seemed adamant that I call from home when I can access the dish screen. Is there actually something you can do to fix this from home?


From everything I've read here, no, the LNBs must be replaced. This is a no charge service call, so I'm willing to play along.

Interestingly, yesterday all the missing channels showed up, but the LNB drift detected message is still there. Locks are now behaving strangely; for example Andy Griffith on TV Land was locked with a G rating. Dish comes tomorrow, so I'll await the results of that and post an update here.


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## BillJ (May 5, 2005)

MikeHou said:


> From everything I've read here, no, the LNBs must be replaced. This is a no charge service call, so I'm willing to play along.
> 
> Interestingly, yesterday all the missing channels showed up, but the LNB drift detected message is still there. Locks are now behaving strangely; for example Andy Griffith on TV Land was locked with a G rating. Dish comes tomorrow, so I'll await the results of that and post an update here.


How about asking the tech for some info on LNB drift you can pass on to the rest of us. I'm currently seeing the drift message when I check status even though my signal strength is 'normal' and I have no apparent problems. I note the message includes comments on weather and trees perhaps being the cause. Seems like there might be things other than a faulty LNB involved.


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## P Smith (Jul 25, 2002)

There is LOF2 drift, ie second oscillator frequency out of spec range 14350 MHz +/- 5 MHz and SW compensation routine. 
Sometimes the routine going to over-correct the drift and a receiver will lock to adjusted transponder.
It possible to adjust the LOF2 in a RF lab with right equipment, but by a nature of the problem, it will continue to change the LOF2 in near future ( aging components, warping PCB, etc).


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## MikeHou (Oct 18, 2006)

BillJ said:


> How about asking the tech for some info on LNB drift you can pass on to the rest of us. I'm currently seeing the drift message when I check status even though my signal strength is 'normal' and I have no apparent problems. I note the message includes comments on weather and trees perhaps being the cause. Seems like there might be things other than a faulty LNB involved.


I won't be there when he comes, unless he arrives late again.

If he gives a techy explanation like P Smith has provided, I would need a translator anyway.


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## MikeHou (Oct 18, 2006)

Dish tech came today, arrived early in the window for a change. He looked at the LNB drift message, replaced the LNBs, message went away.

However, I had unlocked the system a couple of days ago, and when I locked it, I noticed the same behavior as before (most channels missing). I hadn't dug into locks before, so I did now and see that there are channel locks entered for most channels other than locals and HD. Very strange, not sure how that happened. I had the SD duplicates where there's an HD mapped down to the same channel locked out, but that was it. I cleared the locks, set up what I wanted, and all is well now.

Guess the LNBs were heading downhill, so probably good I got them replaced before they were toast.


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## TBoneit (Jul 27, 2006)

I just had them out to change the 110/119 LNB for drift of -6 in the heat of the day and -5 at night. This was during the 100 degree weather this past weekend.

at -6 the 721 and the 7100 both were out of commission and the 622 was fine. 

at -5 the 721 was mostly OK and the 621 was fine. Whatever LNB drift is the 622 handles it better than the older DVRs.


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## kucharsk (Sep 20, 2006)

TBoneit said:


> IWhatever LNB drift is the 622 handles it better than the older DVRs.


LNB drift is what happens with inexpensive consumer grade LNBs as used on DISH systems (as opposed to high stability LNBs or even PLL locked LNBs that are used on commercial or home big dish systems.)

Essentially as temperatures change, the frequencies at which received signals are transmitted to your receiver by the LNB "drift."

Receivers can compensate by this a bit by offsetting the frequency they're expecting to see a particular signal at up or down a bit to achieve a lock or better signal, but once the drift is outside the range it can deal with, it will generate the LNB drift message.


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## Interprises (Feb 12, 2004)

Funny... We have been living with a -7 to -9 drift for the last year and a half. Some time back I was told by a rep that amount of drift was no big deal. Yeah, right...

We would get _mist fade_, not just _rain fade_. It didn't even need to be raining, if there was a good size thunderhead to our south we'd lose signal.

Long story short... they recently did a complete overhaul of our system. One HUGE difference. I don't recall the last time I saw a "Good" system check.


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## liferules (Aug 14, 2005)

When I called Dish this past Monday, they said as long as the drift was less between +8 and -8 it was no big deal. If it was farther out either way, then they may need to be replaced...


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## P Smith (Jul 25, 2002)

By original Dish official paper, the max deviation was +/- 5 MHz, after that LNBF must be replaced.
But soon as they discover high rate of bad LNBF ( any installer will tell mfg id of bad batch), they silently ( not in official papers) increase the range to +/- 8 MHz and tweak SW on certain receivers to compensate the high LOF drift.


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## TulsaOK (Feb 24, 2004)

P Smith said:


> By original Dish official paper, the max deviation was +/- 5 MHz, after that LNBF must be replaced.
> But soon as they discover high rate of bad LNBF ( any installer will tell mfg id of bad batch), they silently ( not in official papers) increase the range to +/- 8 MHz and tweak SW on certain receivers to compensate the high LOF drift.


I've got a deviation of -8 on 129 and -6 on 119. I have a separate dish pointed at 129. Dish will replace the LNB on 129 free of charge. I wonder if I should press the issue with the -6 drift on 119. Also, I think I will ask the tech to re-point my 129 dish to 61.5 since I'm in the SE. The tech I spoke with at Dish said it would be up to the technician to re-point my dish to 61.5. When I had 61.5 before, the signal was very strong; much stronger than 129. I think all my locals and RSN's are now on 61.5 as well as all the HD programming that's on 129.

Stupid Question: I have a ViP722 and a DP501. Would the change to 61.5 affect the programming for the 501?


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## P Smith (Jul 25, 2002)

That's depend on your sub - check EKB which sat hold your programs.


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## jsk (Dec 27, 2006)

Lately, I have been getting more information below the LNB Drift message:


```
LNB Drift Detected
0x00, 0x00, 105(e -6)  [don't really receive any programming from 105 anymore]
0x00, 0x00, 119(e -8)  [I should call them to get that LNB replaced]

STB Health Lite
Tuner 0 as of 06/12/08 4:36pm
Orbital:  14 15 16 21
110       75 69 75 66
119       66 71 72 71
129       0  0  0  0

Tuner 1 as of 06/12/08 2:18pm
Orbital:  14 15 16 21
110       78 73 81 75
119       68 71 77 69
129       0  0  0  0

Value: 0:0
Value: 1:0
Value: 2:0
Value: 3:0
Value: 4:0
Value: 5:0
Value: 6:0
Value: 7:4
Value: 8:1
Value: 9:0
```
Does this mean that my receiver is bad too or is it more information relating to the LNB drift? I did have a weird occurrence yesterday where the picture on TV2 went blank on any channel that I tuned to, but the receiver was acting like it was changing the channels (i.e. I saw the banner at the top with the program name, channel number, etc.). I also checked signal strength and it was fine as well.

Also, my wife unplugged a fan that I have blowing on the receiver causing the internal temperature to go up to 140 degrees and the temperature just outside the receiver was 102 degrees. I either need to find a quieter fan or figure out how to better place the receiver in my cabinet.


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## P Smith (Jul 25, 2002)

Why 129W show 0s ?
"0x00, 0x00" - strange,should be real numbers.


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## jsk (Dec 27, 2006)

I don't know why 129 shows up at all because I don't have anything pointed at 129. I only have a SuperDish pointed at 110 119 and 105. I am not missing any channels (including the "You have a SuperDish at 105" channel). Go figure.

I haven't had any other problems since the screen went black (see my previous post). Maybe I'll wait and see if things get worse. I'm just curious what all of the extra information on that screen means.


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## P Smith (Jul 25, 2002)

Ah, OK. It's explains 00s for 129W, but "0x00" in first strings looks not normal.
Are they always like that ? Could you recheck it ?


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## jsk (Dec 27, 2006)

I just checked it again and it read the same:

0x00, 0x00, 119 (e -8)
0x00, 0x00, 105 (e -6)

I am still getting a signal from 105, 110 and 119

What does the STB Health Lite information mean?


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## P Smith (Jul 25, 2002)

Just smal subset of sats and transponder's signal level.
Full STB Health sending by DVRs to Dish each week.


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