I have a 37 with a black streak developing on screen.

See Mr Martin's stuff at http://www.fixya.com/support/r6150077-basic_lcd_monitors_troubleshooting

u have bad lcd panel

This is a fault developing within the screen, the only remedy is to have the screen replaced, there is no exact answer to why this has happened, it is just the nature of a plasma screens make-up that sometimes a fault can develop like this within the characteristics the display

i have a poula 2150 chain saw i replaced my primer and fuel lines but the lines 1 goes to the tank leaving with no place for all my linesr all

hi all .ive had the same problem,a thick black line down screen.sometimes it flickers from top to bottom and other permantly in view.but i have solved it.forget your ic boards and taking apart tv.have you got either a ps3 or wii connected to tv.if so unplug power lead from socket and relocate in seperate socket.make sure the lead is completely free of any other leads and you might just find this works.i think the power lead creates some sort of frequency that the tv picks up .good luck hope it works

The developers almost never streak. I would be looking at your PCUs. Developers have a tendency to leave voids and dust the paper. PCUs tend to streak as the cleaning blade and charge roller wears out.

not sure if this is the fix or not ...but i was tryin to fix a problem with my tv(not the same as yours)...but in the menu under adanced you can split the screen ....when i do that it puts a blue line down the middle of the screen

This should help -

Developer streak
Developer streak is characterized by a line of dark or missing toner
that stretches from the leading edge to the trailing edge. Replace the
toner cartridge corresponding to the color of the developer streak (for
example, if the streak is magenta, replace the magenta toner
cartridge).

Repetitive defects troubleshooting
Repetitive defects are defects that occur in the same vertical position
on the page, but not necessarily on every page. Most repetitive
defects are caused by problems with one of the following, and are
indicated by the positioning of the defect on the page:

developer roller (at 38 mm)

charging roller (at 44 mm)—see additional information under
“Charge roller set” on page 454.

cleaning roller (at 56 mm)

developer DSD wheels (at 65 mm)

transfer roller (at 66 mm)

transfer drum (occurs once per 11-by-17 inch or A3-sized page,
or every other letter- or A4-sized page)

fuser (at 150.5 mm)

imaging drum (at 195 mm)

transfer belt (at 222 mm)

It could be something on the crt embedded that looks like the screen.

On that product, it is just as likely that a single color drum is bad. Not the developer. That is a more likely problem then the developer.