I have a laserjet 4250n and at the top about 2 inches wide is about 75% black going horizontally from the left side to right side and you can see the letters under the black. and it does not do it very often at all.

Samsung LN46B650 Thin Black Horizontal Lines - Forums - CNET

www.cnet.com > Forums > Samsung

CNETJun 11, 2015 - I'm experiencing thin black lines from the top of the screen to the bottom. ... my lcd tv has multiple lines are horizontal it starts from the right and fades too the left, ... Samsung LN55a950 - Horizontal lines on right side - Forums - CNET
Jun 11, 2015
Samsung 52" LCD TV black lines - Forums - CNET - CNET.com
Jun 10, 2015
More results from www.cnet.com

Plasma TV Repair Horizontal Lines - How to Diagnose ...

? 2:49
https://www.youtube.com/watch?v=h4XWCxUsSVU
Sep 2, 2014 - Uploaded by ShopJimmy.com
I have thin horizontal black lines on the top and bottom areas of my TV. .... Hi, I have a 2011 64-inch 3D Samsung PN64D8000 Plasma TV.

how to fix horizontal or vertical lines on lcd tv - YouTube

? 4:52
https://www.youtube.com/watch?v=k2QpYJp6MU8
Apr 12, 2014 - Uploaded by cr4zyw3ld3r
Hi my LG 47ln5700 tv set has thin greyish black horizontal lineson one side of the .... I hope this works good with Samsung LCD as well....

try to replace magenta , Yellow , CYAN

hi

HP LaserJet 4250n Printer - (Q5401A)

replace the fan --- erro 59.00 is failed fan.

on right or left of printer

Fan RK2-0278-000CN In stock
Cooling fan - Located on left side of printer (FN101)
RoHS: Modified
93.60 0.00 93.60 RK2-0280-000CN In stock
Cooling fan - Located on right side of printer - Provides air to the print cartridge area (FN103)
RoHS: Modified

This is caused either by the fuser or the tonercartridge.

The most common cause is the tonercartridge.
You can test this by forcing a paperjam to stop the paper just after the toner but before the fuser.

To force a paper jam print you can print a page from the manual feed tray and as the last third of the page enters the printer opening the door causes it to halt.

If the black line is there before the toner is bonded to the paper by the fuser you should replace the tonercartridge..

you'll need a new panel, or a new TV, sorry

Again, this was actually HP Laserjet 3800. Problem solved by chatting with HP, and them having me go into a diagnosis mode that disabled cartridge check. Then, I removed the cyan cartridge, the dots went away. They then had me put the black into the cyan slot, and not dots appeared. I had backup toner on hand, swapped in a new cyan and magenta, and all was good. HP agreed to replace the cartridges.

Definately a damaged screen, no way to fix it for less than the cost of a replacement screen sorry.

first, take drum unit out and make sure the blueish-purple colored plastic tab on top of drum is all the way to the left side. if thats not the culprit, then you are most likely looking at a bad contact image sensor or CIS.

hth,
ray

try this
1.when the printer start print turn off the printer after the paper go on side the printer to make paper jam
2.open the printer and pickup the paper out slowly
3.see the print area on the paper if the black par appears on the paper that mean the drum unit faulty if not the fusser unit faulty

1 it is due to horizntal output trnansistor. 2 capacitor connected to horz output. 3 flyback transformer. hope this will help you.