I have a SAMSUNG HDTV Model number SP43W6HL, iv not used it for about 10 months. It has been kept unplugged in my bedroom so its not got damp or banged/bumped in any way. All it now dose when its plugged in, the stand-by light comes on and that is it. can you help me please or give me an idea what might be wrong with it, Thank you.

SOURCE: Samsung HL-S5679W - Power-up issue

There can be a few causes. One of the LED Modules has gone bad, The LED Driver board has gone bad and or the Power Supply has gone bad. You will need to have a good tech look into it.

SOURCE: Why won't my Samsung HL-R4667W DLP tv turn on?

Theres a cover on the back that is vented w/4 screws on like the corners,also theres a symbol that looks like a "T" on it,take that cover off and right behind the symbol "T" an arm like plastic piece is what hits a lever inside when then cover is installed ,flip that little blue lever up and down a couple of times with the set unplugged reinstall cover making sure the "T" is in the position to hit the lever and tighten not too tight.
if this don't work it may be your colorwheel.Good Luck!