Line down the center from top to bottom, 1/2 inch very light , NOT folded.
The vertical section voltages are all normal, as are the waveforms. Still have the very light half inch line directly down the center, with all or no inputs. Possible main module? What fix did the others with this problem come up with?
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
If the lines are slanted up from left to right and spaced several inches apart, you are seeing the vertical retrace line. In that case, you may want to turn down the screen voltage on the green CRT. The instructions for making this adjustment are given in the service manual. It should take just a small tweak to hide the retrace line. If adjusting the screen voltage won't do the job, check for a leaky or improperly biased CRT driver transistor, then compare the video waveforms with one of the other CRTs to make sure the voltage at the vertical blanking interval is correct.
In the worst case, there is a problem with the CRT. This is generally accompanied by occasional arcing (bright green flash or the set shuts down with an error code flashing on the power light).
first to check waveforms going into the vertical output stage. The supply voltage is probably correct since that often determines the size. It almost sounds like the waveform rather than being mostly on (active video) and off for the short blanking period is somehow only on during the last part of the active video thus giving you just the bottom of the picture. If there is a vertical output IC, it may be defective or the blanking input to it may be corrupted. The problem may be as far back as the sync separator. Then again who knows, maybe wait for the schematics.
CAUTION: To prevent damage to the CRT phosphors, immediately turn down the brightness so the line is just barely visible. If the user controls do not have enough range, you will have to locate and adjust the master brightness or screen/G2 pots.
Since you have high voltage, the horizontal deflection circuits are almost certainly working (unless there is a separate high voltage power supply - almost unheard of in modern TVs and very uncommon in all but the most expensive monitors).
Check for bad solder connections between the main board and the deflection yoke. Could also be a bad horizontal coil in the yoke, linearity coil, etc. There is not that much to go bad based on these symptoms assuming the high voltage and the horizontal deflection use the same flyback. It is almost certainly not an IC or transistor that is bad.
According to the model# you have a 27 inch TV so this would mean you have a bad capacitor in the vertical circuit 100uf 35v and you may need to replace vertical IC as well.Call Mats for parts 1-800-628-1118 for owners manual try Encompass Parts 1-800-638-3328.Somtimes if picture pops back to normal then resolder Vertical IC but if thats not happening, replace parts.
Initially, I would suspect that a capacitor at the vertical section is about to fail. This i8s a relatively easy fix and would only require basic knowledge of electronic circuitry and components and a little soldering. The capacitor would be the biggest of the bunch in the vertical section. The vertical section can be identified by the presence of the vertical deflection output IC which is normally attached to a heatsink. Should you be uncomfortable performing a DIY and just winging it as opposed to getting a Service Manual (or at least a schematic diagram), perhaps your best would be to seek the services of a qualified professional.
Hope this be of initial help/idea. Pls post back how things turned up or should you need additional information.
This sounds like a vertical deflection fault. There are some components that are failing in the vertical deflection area that are starting to fail. It is very common in many of the sets that there are electrolytic capacitors in the vertical amp section that are gong out of specifications.
When you have at the top or the bottom of the screen where the vertical axis is compressed, and the picture in the compressed area looks like it is inverted and going over on itself, this is called "vertical fold-over".
An experienced TV service technician should be able to service this for you.