rescan problem with RCA DTA800B

overscanned

DTVUSA Jr. Member
#1
I have purchased and successfully installed more than a dozen of the RCA Mod DTA800B converter boxes. All have been in operation for several months or more and running fine. After the digital switch, I rescanned some of the units and some channels were moved some channels were added, all worked fine. Yesterday, one of my users reported a problem of no response with a unit. I had them turn power off, restore the power, reset to factory default, and start the rescan for channels. The rescan found 4 channels before hanging up at 20% complete. I lef it at 20% for more than an hour. My scand are normally complete in just a few minutes. I brought a replacement unit to the site and all worked fine with 24 channels available. I did a rescan and the same exact problem occurred at the same 20% completion point.

I took another unit to another location to eliminate antenna or other problems. The unit displayed many of the 28 availible channels but after initiating a rescan, it also hung up at the 20% point with only 4 channels. I have not discovered a way to return the units to the prior state. Reset to factory default does not correct the problem.

I still have two units that have been successfully rescanned since the digital switch and they display all channels correctly. I do believe rescanning them now would again duplicate my problem. This looks like a bug in the box to me.

Any suggestions?
 
#2
It's a software fault. part of the really low quality of the DTA800b boxes. i had one which did that and required the plug pulled and then reset to fix it. it also hung at the signal meter menu, where you'd get no data. no beep either.

these boxes run hot too, even with adequate ventilation, so i would say after awhile it takes its toll on the tiny components. the software seems to be very unstable too. it's the only box i know that has bugs within the ROM. i had them 'lock up' with no response from the remote or front panel, and also the issues you're referring to. if the signal gets too weak the audio skips like a scratched compact disc. it's the only box where the audio stream doesn't simply drop to nothing when signal is weak, but skips like that. it's very infuriating.

There are boxes which lose the ability to keep dates and times and default to 'January 1, 1980, in the same fashion as a IBM computer with a dead CMOS battery. so that points to the solid-state memory backup being lost. i really don't recommend this box or the other cheap ones to anyone due to this. it's a failure waiting to happen and more anger at the transition that's really unwarranted.

I'd return them (if possible--coupons don't get refunds) and get a higher quality box. sometimes the extra $10 or $20 is definitely worth it in the long run i wouldn't blame the antenna or other parts.
 
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divxhacker

DTVUSA Member
#3
Have you tried contacting the manufacturer? RCA might have something to use to fix the faults - you shouldn't have to unplug/plug the antenna to get it working right. That's very sloppy. The box is trying to lock onto two signals, and trying to determine which signal to listen to. It sounds like the DTA800 has a "can tuner," not a chip tuner. I'd like to get my hands on one and fully examine it, but I keep getting outbid on this model.
 

overscanned

DTVUSA Jr. Member
#4
I have further diagnosed the issue with the RCA Mod DTA800B converter box. The box contains a channel list, which is cleared and reloaded into an internal memory during the rescan operation. The rescan hangs up at the same location every time. I have found I can get the rescan to continue the search by removing the antenna signal and very quickly reattaching it. Channels are lost during the scan while the antenna is off so it must be reattached immediately. In my case, in the Minneapolis area, tptlife(2-3) and tptwx(2-4) are always lost. I have been able to retain the rest of the 25 channels available. I now believe there is a firmware issue in the converter box that causes it to mishandle on of those situations that are "never supposed to happen" but still do. There is also a likely issue with channel 2 Tpt in Minneapolis causing the problem in the first place. My early scans, done shortly after the switch to digital, worked fine and I still have channels 2-3 and 2-4 available on those converters.

Overscanned
 
#5
I have further diagnosed the issue with the RCA Mod DTA800B converter box. The box contains a channel list, which is cleared and reloaded into an internal memory during the rescan operation. The rescan hangs up at the same location every time. I have found I can get the rescan to continue the search by removing the antenna signal and very quickly reattaching it. Channels are lost during the scan while the antenna is off so it must be reattached immediately. In my case, in the Minneapolis area, tptlife(2-3) and tptwx(2-4) are always lost. I have been able to retain the rest of the 25 channels available. I now believe there is a firmware issue in the converter box that causes it to mishandle on of those situations that are "never supposed to happen" but still do. There is also a likely issue with channel 2 Tpt in Minneapolis causing the problem in the first place. My early scans, done shortly after the switch to digital, worked fine and I still have channels 2-3 and 2-4 available on those converters.

Overscanned
Great post, and it is unfortunate that converter box makers have not included a way to upgrade the firmaware with their boxes. With RCA, this is on their 800B/revised box too. :bolt:
 

overscanned

DTVUSA Jr. Member
#6
DTA800B problem fixed.

I am happy to report the problem with the converter box hanging up during a rescan at the 20% point has been corrected.

My interpretation of the problem is that the information packets that are transmitted by the station contained an incorrect CRC code. The box correctly reread the information packet but the firmware in the box has no provision to abort after a resonable number of failed read attempts. The problem with the CRC code was corrected by TPT channel 2.

I want to thank all who assisted in correcting this problem
 

1inxs

DTVUSA Member
#7
I am happy to report the problem with the converter box hanging up during a rescan at the 20% point has been corrected.

My interpretation of the problem is that the information packets that are transmitted by the station contained an incorrect CRC code. The box correctly reread the information packet but the firmware in the box has no provision to abort after a resonable number of failed read attempts. The problem with the CRC code was corrected by TPT channel 2.

I want to thank all who assisted in correcting this problem
Thanks for posting back with your results. It's always nice to find a successful conclusion to a thread.
 

berl

DTVUSA Rookie
#8
Thanks overscanned. My wife was going to kill me (is that politically correct now?) because after the dtv switch she lost all the ch6 stations out of Tulsa. Her rescan stopped at 40%. I just rescanned and removed the antenna and it finally did a full scan. Now she can watch TV and I can sleep!
 

Metal

DTVUSA Rookie
#9
I've had to do rescans more often than not trying to find lost channels. I think some of my local broadcasters have been messing around with their towers too which makes scanning kind of mandatory. It's nice to be able to find answers, otherwise we'd probably been stuck with a few less channels though we got our information from our local news, not here, but there is a lot of information here.
 
#10
my converter doesn't 'skip' no signal channels like some do but i did lose NBC/WX/THIS a few hours last night, said flat out 0% but then went on an hour later at a great 65% (which is plenty for a Magnavox box, which works till it's below 18% to pixellate)

From what i have experienced, both the RCA and Apexes skip channels if you're channel-surfing and you land on a bad no signal one for whatever reason then scan up. the next time you go back the channel will be MIA and redirect to the next lower one. i don't know why that is.
 
#11
I am happy to report the problem with the converter box hanging up during a rescan at the 20% point has been corrected.

My interpretation of the problem is that the information packets that are transmitted by the station contained an incorrect CRC code. The box correctly reread the information packet but the firmware in the box has no provision to abort after a resonable number of failed read attempts. The problem with the CRC code was corrected by TPT channel 2.

I want to thank all who assisted in correcting this problem

Overscanned,
How did you determine that it was a problem with the CRC Code? Were you able to talk to someone at TPT to get them to correct the problem? Because it looks like the problem is back. I am in the same reception area (Minneapolis/St. Paul) and have encountered the same problem this week. I had to rescan due to one of the other local channels (29) changing their configuration. I have three RCA boxes at two different sites that all hang at 20% until I do the antenna unplug trick. They had channels 2.3 & 2.4 before the rescan, but now they are gone.

I'm having problems that I'm convinced are related on three other receivers. I have two Philips DVDR/VCR combos (same model, different firmware levels) that both refuse to put TPT-Life & TPT-Wx on 2.3 & 2.4. Instead the channels show up on 16.1 & 16.2 (and I get a 16.3 & 16.4 that have no picture or sound). Also my 6 month old 47" Vizio LCD tv keeps finding two blank channels at 16.8 & 16.9.

I am wondering if part of the problem stems from the fact that they are trying to map two different analog channels (34 & 16) onto the same base digital channel (2.X). Maybe what confuses the RCA box is the fact that it tries to map the two channels on 16 to 2.3 & 2.4 before the channels from 34 have been mapped to 2.1 & 2.2?

I sent an email to TPT on Wednesday night explaining the problem in great detail and got the "Try the rescan without the antenna then unplug for an hour then rescan again" response. If you were able to get them to fix the problem two months ago, I would think they ought to be able to fix it again.

If I am having a problem involving channel 16 on 5 out of 7 of the receivers in my house I would think there would be problems with a significant number of other OTA viewers.
 

Aaron62

Contributor
Staff member
#12
If I am having a problem involving channel 16 on 5 out of 7 of the receivers in my house I would think there would be problems with a significant number of other OTA viewers.
Is channel 16 UHF or VHF? Also, are any of the 2 working receivers receiving channel 16 a 2nd generation ATSC chip (ie: DTVPal Plus)?
 

overscanned

DTVUSA Jr. Member
#13
Overscanned,
How did you determine that it was a problem with the CRC Code? Were you able to talk to someone at TPT to get them to correct the problem? Because it looks like the problem is back. I am in the same reception area (Minneapolis/St. Paul) and have encountered the same problem this week. I had to rescan due to one of the other local channels (29) changing their configuration. I have three RCA boxes at two different sites that all hang at 20% until I do the antenna unplug trick. They had channels 2.3 & 2.4 before the rescan, but now they are gone.

I'm having problems that I'm convinced are related on three other receivers. I have two Philips DVDR/VCR combos (same model, different firmware levels) that both refuse to put TPT-Life & TPT-Wx on 2.3 & 2.4. Instead the channels show up on 16.1 & 16.2 (and I get a 16.3 & 16.4 that have no picture or sound). Also my 6 month old 47" Vizio LCD tv keeps finding two blank channels at 16.8 & 16.9.

I am wondering if part of the problem stems from the fact that they are trying to map two different analog channels (34 & 16) onto the same base digital channel (2.X). Maybe what confuses the RCA box is the fact that it tries to map the two channels on 16 to 2.3 & 2.4 before the channels from 34 have been mapped to 2.1 & 2.2?

I sent an email to TPT on Wednesday night explaining the problem in great detail and got the "Try the rescan without the antenna then unplug for an hour then rescan again" response. If you were able to get them to fix the problem two months ago, I would think they ought to be able to fix it again.

If I am having a problem involving channel 16 on 5 out of 7 of the receivers in my house I would think there would be problems with a significant number of other OTA viewers.
I rescanned two of my units this morning to verify they are still operational. I am located quite a distance fron the Twin Cities but am still able to pick up 25 stations. You should expect at least similar results.

The channels detected:
2-1,2,3,4
4-1
5-1,2
9-1,2
11-1,2
23-1,2
25-1,2,3,4,5
29-1,2
41-1,2,3,4
45-1
There is no sound detected on channel 25. I was told this is because of a very weak transmitter/antenna configuration used by the station.

The converter box does not have the capability to deal with erroneous signals from the station and will simply retry the receive sequence until a correct data packet is received. Since I was able to rescan my units this morning, I hope whatever issue you had was corrected by now.

My previous discussions were with an Engineer working with RCA to correct issues with the converter box. I did not have direct discussions with TPT.
 
J

Jzalmo

Guest
#15
I live in NC, had the same problem. I do not understand all the technical phrases, but I carried my box connected to rooftop antenna to my TV with rabbit ears & rescanned to fix it.
 

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