Zenith Digital TV Question

[D H A C]

I'm attempting to fix an old Zenith model SG2795BG. This has an intermittent
teletext type problem. Almost looks like the teletext pops up or flashes on
the screen about anytime. (and yes the teletext feature is turned off)
It's been several years since I've worked on any of these (it's been several
years since I've worked on any TV)
My questions are does anyone know which IC on the 9-700-30 controls the
teletext? Will the TV work without this IC? And.were/are there any flashes
or ZTips out regarding this type of problem on the "digital" TV's?

TIA
Steve

 

[Mr. Lee]

"> My questions are does anyone know which IC on the 9-700-30 controls the

teletext?

Will the TV work without this IC? NO
And.were/are there any flashes

or ZTips out regarding this type of problem on the "digital" TV's? Pull

all IC'S and check for black shit on pins clean and plug IC'S back in.

Teletext IC may be bad.

I have a complete Main Board with all IC'S for sale.

[email protected]

 

[RonKZ650]

I'd recommend discarding the set. Zenith went all out on this Digital set, but
it was a really bad design for servicability. Here is what Zenith originally
said to do to fix these sets to authorized service centers. "Determine which IC
is the most likely to cause the symptom, replace it, if problem is still there,
determine the second most likely, replace it." You do this until the set
eventually is fixed, hopefully before you replace all 20 ICs, which are all
backordered at any time, and $30-$40 each. Plus each time you move the plugs on
the boards to gain access, wires begin to break, causing multiple intermittents
to repair after the main problem is fixed, plus most have bad picture tubes. A
new 9-700 board comes with no ICs. No easy way to fix this set, unless you go
with the previous posters used board. Good luck, you're going to need a *lot*
of it. Many an hour spent cussing and wasting time on these pieces of junk.

 

[David Harris]

My questions are does anyone know which IC on the 9-700-30 controls the
teletext?

IC 6004 Teletext processor
IC 6005 Teletext memory

You cannot remove this IC without loosing video.

David, on the Illinois prairie.

 

[D H A C]

Thanks for the help and suggestions. I've removed and reinstalled all
socketed IC's on the 9-700 and so far the TV seems OK. Looks like the 27" TV
has joined the ranks of the 13" and 19" TV's as a throw away.....

Steve

 

[Andy Cuffe]

Thanks for the help and suggestions. I've removed and reinstalled all
socketed IC's on the 9-700 and so far the TV seems OK. Looks like the 27" TV
has joined the ranks of the 13" and 19" TV's as a throw away.....

Steve

Two common problem I've seen with these are bad soldering (mainly on the
IC sockets) and bad small electrolytics (look for any light blue ones).
The caps leak electrolyte when they fail.

 

[ed]

Two common problem I've seen with these are bad soldering (mainly on the
IC sockets) and bad small electrolytics (look for any light blue ones).
The caps leak electrolyte when they fail.

I have seen this several times. On the 9-700 board, resolder the large
ic that is directly beneath the raised housing.

 

[D H A C]

Thanks for the recommendation. I'll resolder next time I take the TV
apart....looks like a pain to remove the lower shield.
It is improved since I reseated the IC's but still does happen once in a
great while...

Thanks again,
Steve