View Full Version : Ge 802
stusnyder 11-13-2011, 10:07 AM Dug this chassis out last night, it has been totally recapped, some resistors replaced. It has a raster, but no picture. I used a B&K television analyst and injected video at the v14 video amp tube. I got no test pattern but I did get some kind of signal thru, because the rastor changed state. Any suggestions where to look next?? This is one set I'd really like to get finished.
compucat 11-13-2011, 10:26 AM Dug this chassis out last night, it has been totally recapped, some resistors replaced. It has a raster, but no picture. I used a B&K television analyst and injected video at the v14 video amp tube. I got no test pattern but I did get some kind of signal thru, because the rastor changed state. Any suggestions where to look next?? This is one set I'd really like to get finished.
Try injecting a signal at the picture tube where the video amplifier connects. If you get a picture then the trouble is in the video output circuit. It should not be too difficult to isolate provided you are injecting the right kind of signal. That is pure video, not RF.
vts1134 11-13-2011, 02:52 PM Good luck with the 802. I'd love to see a photo when you get a picture. I'm really fond of the the look of the sister set to yours, the 801.
stusnyder 11-13-2011, 06:40 PM Try injecting a signal at the picture tube where the video amplifier connects. If you get a picture then the trouble is in the video output circuit. It should not be too difficult to isolate provided you are injecting the right kind of signal. That is pure video, not RF.
Anybody know what pin on the crt?
David Roper 11-13-2011, 07:12 PM The video is cathode modulated--through a .1 mfd cap. Cathode is pin 11.
stusnyder 11-14-2011, 09:08 PM The video is cathode modulated--through a .1 mfd cap. Cathode is pin 11.
I injected video at the terminal strip where the wire from the crt pin 11 connects...only get horizonal lines. So I disconnected the wire and tried it directly to the crt, then I loose raster all together.
leadlike 11-15-2011, 12:29 AM When I worked on my 802, I had the same issues-I think a mica cap went bad inside that awful tuner, and killed signal input. Anyway, injecting video in the same manner you did, I only got horizontal lines. Injecting video at the video amp really messes up the horizontal frequency. Adjust the coarse horizontal control (You'll need a plastic diddle stick for this, I ground down a chopstick to fit, as a screwdriver throws off the frequency more) until a picture pulls in. Hope that helps!
stusnyder 11-15-2011, 04:06 AM When I worked on my 802, I had the same issues-I think a mica cap went bad inside that awful tuner, and killed signal input. Anyway, injecting video in the same manner you did, I only got horizontal lines. Injecting video at the video amp really messes up the horizontal frequency. Adjust the coarse horizontal control (You'll need a plastic diddle stick for this, I ground down a chopstick to fit, as a screwdriver throws off the frequency more) until a picture pulls in. Hope that helps!
The problem is similar as you explained, although I got a feeling there probley more wrong with it. If I inject sync signal, I get the black horizontal lines that are shown in my B&K user manual.
Funny I usually play a trf radio when I'm down there working and usually get all kinds of squeeling noises out of the radio when I mess with the tv chassis.
I'll make up a non-metal screwdriver tonight and see what that brings.
stusnyder 11-15-2011, 09:17 PM Adjust the coarse horizontal control (You'll need a plastic diddle stick for this, I ground down a chopstick to fit, as a screwdriver throws off the frequency more) until a picture pulls in. Hope that helps!
Got somewhat of a picture, as you can see, the horizontal has interference in it. Vertical locks good. Don't got much contrast control. Any sugestions where to go next?
leadlike 11-16-2011, 03:12 AM You won't have any contrast control. On this set, the contrast control raises and lowers the plate voltages on the tubes in the IF string. Since you've bypassed all that, twisting the contrast control will have no effect.
Try to inject a signal from a DVD player next. My BK 1077 produced odd results like that on my 802 project, while the video from my DVD worked fine.
kvflyer 11-16-2011, 09:34 AM Got somewhat of a picture, as you can see, the horizontal has interference in it...
Could that be a bad capacitor in the yoke? They often have mica caps inside of the yoke. I don't have a schematic in front of me so I may be way off base...
stusnyder 11-16-2011, 12:25 PM Try to inject a signal from a DVD player next. My BK 1077 produced odd results like that on my 802 project, while the video from my DVD worked fine.
Tried that, did not get any results. Might not had it hooked up correctly? I set up the 1077 for IF and it seems I'm getting something thru the IF stages to the video detector. Still got that blasted white vertical line though...
Not much left in there for stock components. All the mica's and a few resistors are still original. Getting something thru the tuner Rf-wise but not like it should be.
stusnyder 11-19-2011, 08:14 AM Making some progress
kvflyer 11-19-2011, 08:56 AM Making some progress
I would say you are!
stusnyder 11-19-2011, 09:19 AM I would say you are!
Thats video injected at the v15b tube dc restorer which is a 6h6.
I have to go thru the IF stages next.
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