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Zenith CRT TV - black horizontal bars
romshark:
I didn't look into any of those controls. I'll look it up and hopefully try adjusting it after work.
edit: took a quick look. The flyback has 2 controls. One is marked focus, and the other is unmarked. I'll try tweaking that second one (which should be voltage or brightness) later.
romshark:
So I gave it a shot. The other control on the flyback made the picture go more red or more blue/green. I did try the focus control too, but neither one affected the dark bars.
The search continues.
romshark:
So I've come across 2 different things.
First, the inside of the back case has a diagram of the controls. I uploaded a picture accordingly. Unfortunately, it states right on the label "High Voltage Not Adjustable". I think that's the screen voltage (please correct me if I'm wrong). Anything else here look like it might be useful?
Second, I believe I have tracked down a PDF schematic of the chassis board. Uploaded that too, of course (available at the bottom of this post). The site had my model listed, though the schematic itself lists "2767SL" along with similar numbers. I think it's for a different country, but still close enough to my TV.
Not sure if it'll help for fixing the dark bar issues. If that can be fixed though, it may help with RGB modding.
Zebidee:
I don't think that "High Voltage Not Adjustable" means that you can't adjust the screen voltage, it is just a general warning to not try to tamper. Of course, you will ignore that!
Having said that I am stumped why adjusting screen voltage on flyback is just altering your colour mix/purity! It should affect overall screen brightness. With brightness in neutral position and a dark screen, you adjust it up until you can see the flyback retrace lines (diagonal, near top), then adjust it back down until lines are gone. Then adjust focus as necessary.
I'm guessing that your black bars come from a power supply issue, but have no idea what specifically and don't know your TV.
You might need to expand your net to find help for this one. This forum branch is more focused on arcade monitors. There are a couple of FB groups that you might find worthwhile, "Vintage CRT Troubleshooting and Repair" (fairly good, not bad) and "The CRT Collective" (not as good, but some are knowledgeable). If they can't help directly, maybe at least they can point you to a local repair place.
Mike A:
Drive around your neighborhood and find another CRT on the curb. Or go to Craigslist. They are free or at the very least cheaper than you time and aggravation are worth.
It is a ---smurfing--- Zenith TV. Let it die.