I have a horizontal line

Hi! Only at booting, or all the way using the PC?

This problem and solution were posted previously. The following is the link:

http://www.fixya.com/support/t7775296-model_55sv670u_screen_horizontal

A single horizontal line on your CRT Television indicates that the Vertical Drive Transistor has failed. Not as large and easily accessible as the Horizontal Output Transistor, the VDT should be fairly easly to locate and replace.

USE CAUTION INSIDE YOUR TV CASE! EXTREMELY HIGH VOLTAGES CAN KILL YOU!

Sounds like one of the components and/or screen is going or gone,. the "event horizon" of screen deaths, not good. sounds like this one may need to go into the repair shop,....may only be a small component and not whole screen. best to get estimate and call repair shop with issue first...

check the supply at horizontal driver trans former ,if voltage is correct at ho/driver trasistor ...then check allthe fusible resistances from power supply,,,if tv is taking h/oscillation for awhile ,,give more screen control in lot,,, & see for a horizontal line ,,,before tv becomes off,,, if so vertical ic problem...

What color are the horizonal lines ??

Try changing the toner and cleaning the rollers.

It is my guess that you have some intermitent solder connections in the Vertical output circuit.
Hope this helps,
Skyassoc

If you use Adobe Photoshop, you can use ruler tool. Just drag from the start point to the end point of your horizontal (as example horizon line from a landscape image). It will display the Arbitrary degree in bar (just below the menu bar).


P.S.: If this information was helpful, please rate this solution.

The problem sounds like a vertical deflection issue form what you describe.
On average they are usually in the simple repair categories. On average they would run in the $50 range if you take it to a reputable repair shop.
There are several possibilities
Bad capacitor (s)
Bad vertical IC
resistor in the power supply to the vertical circuit changing value

This Nikon's expertise to fix - contact customer support- they may repair or offer a replacement.