Question: Wide black section obscures picture -RCA 800DTA

Dave_s

DTVUSA Jr. Member
#1
While viewing Ch 7.1 (2PM) in Panorama City, Calif, the picture looks normal quality. Later while viewing, suddenly, a large section of the picture becomes not viewable due to a black wide square shape on screen. Black square shape is full width and remains stationary. Starts 25% down from top and ends 25% up from bottom of screen. If we change to channel 7.2 and then immediately switch back to 7.1, the black square is gone. Typically the black square occurs many times during the hour show. Some days it occurs very frequently. Have not seen this on any other channel with this converter or the Zenith box.

Not sure if this is a problem with that program or my converter box.
Dave_s
 

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Dave_s

DTVUSA Jr. Member
#3
Hmm, do you have CC (Closed Caption) enabled? The placement of the black rectangle looks a little high for that though.
No, Closed Caption is not enabled.

Also, the black section just appeared on Ch 7.1 at 11A.M. this morning.
Previously only appeared at 2P.M. This time, the black section turned off by itself.

With TV running all morning on ch9, or other channels, do not see the black area.
 

JeepJeep

DTVUSA Member
#4
Dave, do you have any other TVs in your house to compare to? It could be a converter box problem or it could be a broadcast problem. Does it only happen to channel 7.1?
 

Dave_s

DTVUSA Jr. Member
#5
Dave, do you have any other TVs in your house to compare to?
It could be a converter box problem or it could be a broadcast problem. Does it only happen to channel 7.1?
Yes, we do have other TVs that use other brand converters.

Never, on the dining TV r the Lani TV, do we ever see that black bar on any channel.

Only see the black bar on the bedroom TV and then only on channel 7.1 so far.

Also, now the black bar appeared on 7.1 at 11 A.M. today.
 

Aaron62

Contributor
Staff member
#6
While viewing Ch 7.1 (2PM) in Panorama City, Calif, the picture looks normal quality. Later while viewing, suddenly, a large section of the picture becomes not viewable due to a black wide square shape on screen. Black square shape is full width and remains stationary. Starts 25% down from top and ends 25% up from bottom of screen. If we change to channel 7.2 and then immediately switch back to 7.1, the black square is gone. Typically the black square occurs many times during the hour show. Some days it occurs very frequently. Have not seen this on any other channel with this converter or the Zenith box.

Not sure if this is a problem with that program or my converter box.
Dave_s
Hey that's ABC right? You're in my neck of the woods. ;) I've never had a problem with that channel although I don't watch it that much. What brand converter box are you using? I'm going to guess, Magnavox??
 

Dave_s

DTVUSA Jr. Member
#8
Hey that's ABC right? You're in my neck of the woods. ;) I've never had a problem with that channel although I don't watch it that much. What brand converter box are you using? I'm going to guess, Magnavox??
The box I am using that shows the black section is an RCA model 800DTA.
I also have a Magnavox on another TV.

Just to be certain, in case I did push CC, I did just reset the RCA to CC 'factory defaults'.
 

Dave_s

DTVUSA Jr. Member
#9
Sounds like it could be yet another Teletext box, a close cousin of Closed Captioning that got built into TVs and tuners but which is almost never used. Best description of what it is and how to track it down is Get rid of that pesky black box! by Jeff Hartman at WSYR-DT in New York state.
Many thanks for the URL to that discussion.

I reset my RCA converter to 'factory defaults' just in case I did possibly push CC.

This specific TV is VERY OLD and does not have a CC converter built-in.
Can this old TV possibly have Teletext built in but not have a CC converter?
 

FOX TV

Contributor
#10
Try the converter box on another TV. How do you feed this TV? Are you using the coaxial output, or the audio / composite video ( the Red/white/ yellow connectors on the back of the box ) If using the coaxial output, that could be a faulty RF Modulator in the converter box or the TV.

Does your signal pass through a VCR, as it could have a faulty or drifting RF Modulator too. That signal looks as if it is being produced by some type of modulator, based on what looks to be part of the Vertical Blanking Interval, or line 21 data (CC DATA) at the top of the black box.

Does any of your equipment have picture in picture capability? If so, something could be triggering it to come on. Try using the audio / composite video connection if you are not using it now. The TV may have some bad or failing capacitors that can also cause that symptom, especially if it is an older set with a lot of hours of use on it.

Hook up a different box to that same TV and see what you get. Just change stuff around and see if the problem follows the box, or does a different box hooked to the same TV produce the same results on that TV?
 
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Dave_s

DTVUSA Jr. Member
#11
Try the converter box on another TV. How do you feed this TV? Are you using the coaxial output, or the audio / composite video ( the Red/white/ yellow connectors on the back of the box ) If using the coaxial output, that could be a faulty RF Modulator in the converter box or the TV.

Feeding converter into VCR, out of VCR into TV using the audio/composite video cables.


Does your signal pass through a VCR, as it could have a faulty or drifting RF Modulator too. That signal looks as if it is being produced by some type of modulator, based on what looks to be part of the Vertical Blanking Interval, or line 21 data (CC DATA) at the top of the black box.

No modulator I think since am using audio/composite video cables.

Does any of your equipment have picture in picture capability?

No 'picture in picture', simply too old TV.

If so, something could be triggering it to come on. Try using the audio / composite video connection if you are not using it now. The TV may have some bad or failing capacitors that can also cause that symptom, especially if it is an older set with a lot of hours of use on it.

Ok, you are referring to drying out high ESR filter caps. Sure is possible.

Hook up a different box to that same TV and see what you get. Just change stuff around and see if the problem follows the box, or does a different box hooked to the same TV produce the same results on that TV?
Certainly can run this TV with different box.
Lots of trouble shooting for me to do. Many thanks.
 

FOX TV

Contributor
#12
Certainly can run this TV with different box.
Lots of trouble shooting for me to do. Many thanks.
Failing capacitors can certainly cause this issue, but normally if it is a capacitor issue, the black box will normally be stationary, and not drift around the screen. We have replaced many a capacitor in CRT monitors, and that usually fixes any problems similar to this one.
 

Dave_s

DTVUSA Jr. Member
#13
Failing capacitors can certainly cause this issue, but normally if it is a capacitor issue, the black box will normally be stationary, and not drift around the screen. We have replaced many a capacitor in CRT monitors, and that usually fixes any problems similar to this one.
I do think the size and position of the very black box is constant.
I did reset the BOX CC option back to factory 'Default'.
Have not seen the black box since.
If seen again, then swapping boxes is the next step to determine if box or OLD SHARP TV is the source.
 

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Aaron62

Contributor
Staff member
#14
I do think the size and position of the very black box is constant.
I did reset the BOX CC option back to factory 'Default'.
Have not seen the black box since.
If seen again, then swapping boxes is the next step to determine if box or OLD SHARP TV is the source.
Well good so far. Hopefully that solved it. I do recall having an old TV that did something like that (before the digital transition a 4-5 years ago) and I think it had something to do with the CC on the actual TV. Probably unrelated to your problem though.
 

Dave_s

DTVUSA Jr. Member
#15
I do think the size and position of the very black box is constant.
I did reset the BOX CC option back to factory 'Default'.
Have not seen the black box since.
If seen again, then swapping boxes is the next step to determine if box or OLD SHARP TV is the source.
Resetting the box to factory defaults DID NOT solve the problem!!!!!

Ch 7 program did the same thing again.
NOW IS Solved, I think!

Made black screen disappear by pushing "CC" on the remote. On screen saw "CC Service 5", and the black section vanished.
So far, NOW, do NOT see 'black screen'.

Cycling through box "CC MENU" options does NOT disable "CC" with the RCA 800DTA box.

Many thanks to EVERYONE for all of your 'very helpful' suggestions.
Dave_s
 

Dave_s

DTVUSA Jr. Member
#16
Hmm, do you have CC (Closed Caption) enabled? The placement of the black rectangle looks a little high for that though.
Your suggestion to disable "CC" was correct. I thought "CC" was disabled. I was wrong.
Finally pushed "CC" button on remote. That eliminated the solid black section on screen.
Good advise!!!!!!!!!!!

Many thanks. Dave_s
 
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