Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Predicta Holiday Image Tearing at Top of Image
#1

Hi all!

Need some help troubleshooting this issue. I just completed a compmete electrical restoration on this model and almost everything is working fine aside from tearing at the top of the image. I've included photos of the image as well as the top and bottom of the chasis. I've gone and made sure all the connections on the sweep board are good as well as making sure the tube sockets are making good contact. The issue persists with other tapes and on testing the VCR with another set it's perfectly fine.

Thanks for the help!!


Attached Files Image(s)
                           
#2

There are couple of folks here, who are knowledgeable in TVs.
This said, at least one of them participates in Facebook's "Predicta" group, where most people are knowledgeable about the Predicta.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
#3

Look at the vertical wave form. If caps have been replaced in those circuits there may be an issue. Check all ground connections especially if they are riveted to chassis, solder those with a large bolt iron. Be sure there is no heater/cathode leakage in the vertical oscillator and vertical output tubes.

GL

Chas

Pliny the younger
“nihil novum nihil varium nihil quod non semel spectasse sufficiat”
#4

You set is having trouble locking after the vertical retrace interval..Have you adjusted the coarse horizontal hold and ringing coil as described in the service info? Also, looks like you might be using a signal source with macro vision copy protection
#5

Also what effect does adjusting the horizontal hold and contrast have?
#6

Bob Andersen Wrote:Also, looks like you might be using a signal source with macro vision copy protection.

Although I don't work with TVs a friend who buys them and sells them on the auction site has enlisted my aid in the past. He has no way to create an NTSC signal to show that the CRTs are working. What I bring for the purpose is my first DVD deck, a single-layer Sony, and a couple of old DVDs of "Burns and Allen" and "You Bet Your Life," plus an RF modulator.

Dale H. Cook, GR/HP/Tek Collector, Roanoke/Lynchburg, VA
https://plymouthcolony.net/starcity/radios/
#7

Hello guys,
Yes , bob brings up a good point and that why I have macro vision copy protection union that corrects that problem this was a common problem with older tv's

I used to sell those units at my tv repairshop.

Sincerely Richard
#8

Aaaah yeah. Macrovision. Good old “flagging “. As mentioned a filter might help. Available on Amazon. I use on on my dvd recorder. Works great! Had a similar problem on some of the older Sears sets, seems like we had to change a couple resistors in the horizontal section. About all I remember tho. Been a few days.

If I could find the place called "Somewhere", I could find "Anything" Icon_confused

Tim

Jesus cried out and said, "Whoever believes in me , believes not in me but in him who sent me" John 12:44
#9

Thanks for the ideas everyone. I just got the chance to sit down and play with the set today, however when I powered it on there is no video at all aside from the raster. I'm going to go through and check connections in case something may have come loose while sitting somehow. There was a brief 15ish seconds where video and sound came through perfectly, but it quickly went away and I'm not even sure what happened to get that far. I will update when there is progress to report!
#10

I know this thread is a few months old, but I was looking through things since I have a pedestal I'm going to play with and I noted in the 5th picture, upper RH corner there's an orange drop cap connected to pin 6 of what looks like the horizontal output tube. Is that soldered?? It looks like the wire is just wrapped around the terminal.

If I could find the place called "Somewhere", I could find "Anything" Icon_confused

Tim

Jesus cried out and said, "Whoever believes in me , believes not in me but in him who sent me" John 12:44




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco 42-345 Restoration/Repair
Vlad95, Thank you for the stringing guides and wow there are so manyosanders0311 — 06:01 PM
5U4 vs 5Z4 tubes
A pre war Hallicrafters, and an early one too, very nice! 1936 is pretty early for metal tubes too, which would explain ...Arran — 05:58 PM
Philco 42-345 Restoration/Repair
Thanks Rod, "When you hear the background hiss and no station it usually indicates that the oscillator quit" ...osanders0311 — 05:52 PM
Philco 42-345 Restoration/Repair
RodB :beerchug:Vlad95 — 10:22 AM
Philco 42-345 Restoration/Repair
Vlad, you nailed it. Swiss and German roots.RodB — 09:54 AM
5U4 vs 5Z4 tubes
Well this is a Hallicrafters SX/9 circa 1936. No real issues so far although I dodged a real bullet with a cap that was...bridkarl — 07:59 AM
5U4 vs 5Z4 tubes
The pinout is the same but the 5U4 has a 3 amp filament, verses 2 amps or less on the 5Z4. I think that the pinout of a ...Arran — 12:04 AM
Philco 42-345 Restoration/Repair
By the way. osanders0311 Take a look here: Dial cord stringing Guides May be here you can fount correct string settin...Vlad95 — 11:15 PM
5U4 vs 5Z4 tubes
5U4 and 5Z4 almost identical. I think nothing happened if you left 5U4 instedad 5Z4 long time. Just heater current 5U4 ...Vlad95 — 11:02 PM
Philco 42-345 Restoration/Repair
Hello Vlad95 , Very Funny ! Sincerely Richardradiorich — 11:01 PM

[-]
Who's Online
There are currently 1287 online users. [Complete List]
» 1 Member(s) | 1286 Guest(s)
Avatar

>