Well, those of you who have no idea why a Screen Voltage (technically known as G2) adjustment may interest you, here is a photo of a bad adjustment (too high).
You may also experience smeared colors… this is caused by a low adjustment. To correct this, we need to get the back off of the TV. It would be a good time to unplug it if you have not already done so. Next we locate the FBT (Fly-Back Transformer).
This is a 20” model and it has 2 knobs. Your FBT may vary, as some slim designs and some large tube models may have 3 knobs.
You will need to look closely at the knobs; they will be labeled “Focus” or “Screen”. On units with 3 knobs, there will be 2 focus knobs and 1 screen. For now, we will be working with at the Screen knob only.
With the adjustments identified, we are ready to plug the TV in (including your standard cable connection) and turn it on… BECARFUL!!! For the rest of this adjustment, we will be working inside of an electrically charged TV. We also need to normalize the picture, so go into your TV menu and adjust the Picture and Brightness settings to the middle or center.
If your TV normally displays a black screen when you do not have a signal connected, ex: Video input 1, then this will be the quickest and easiest setup for you to use. However, if you are not so lucky, you may need to bust through your DVD video collection and find a “between scenes” shot that you can pause on to give you as black of a picture as possible. Eliminate as much light in the room as you can (just remember, you still need to see what your doing)… we want a good view of the screen without the interference of ambient lighting.
Once you have your black screen all set, we are now ready to proceed to the adjustment. If you have lines on the screen, see (HIGH)… if you have color smear, see (LOW).
HIGH: If you have some lines in the picture with a washed out appearance, your Screen voltage is too high. You will need to turn the Screen knob on the FBT counter-clockwise. Do this slowly, until the lines are no longer visible. If you still have a small amount of illumination coming from the screen, back it down a touch further until this just disappears.
LOW: If you have smeared colors in the picture that seem to trail of the edges, your Screen voltage is too low. You will need to turn the Screen knob on the FBT clockwise. Do this slowly, until you just see some lines zigzagging top to bottom on the screen. Now, you will need to turn the Screen knob on the FBT counter-clockwise. Do this slowly, until the lines are no longer visible. If you still have a small amount of illumination coming from the screen, back it down a touch further until this just disappears.
The final set, switch the TV input over to your cable input and check out the picture. Take a good look at some bright scenes and dark scenes. Do they look ok? Adjust the Picture and Brightness in your menu… can you set the picture to your liking? If so, you are all set. If not, double check your work (remember to normalize the Picture and Brightness setting).
If you are unable to adjust the Screen voltage as described above, you may have a High Voltage problem with your TV. This will require a repair and is not covered by this tutorial.
If you are all set and the adjustment is good, we should have a quick look at the focus adjustment. Return the TV to your Black screen setup. Press the TV menu button to give you nice fixed display to focus. Adjust the focus knob(s) until you have the clearest picture. It’s important to balance the center of the picture with the corners of the picture. If the center is too sharp and the edges and corners are blurry, it is not a good adjustment. Do your best, you are the final judge of your work here.
Once you have finished the adjustments and verified the picture with your cable picture, you are ready to close it up and return the TV to normal service. Unplug the TV, replace the back cover… enjoy!
I hope this was helpful. If you benefit from this tutorial, please leave some feedback.