It could be a main board, but it could be a backlight problem. To verify this, turn on the set, dim the lights in the room, shine a bright flashlight on the screen. If you see a faint picture, you have a backlight problem.
Sound like the power supply board has gone out .Unplug the tv for 2 or 3 minutes and plug it in again and try to turn on. Some times they will come on .But It sounds like the PSB is going out .
Does it flash in a pattern or does it constantly flash - like 7 flashes then pause then 7 flashes? Or is it constant without pauses? Are you using a new power strip? It could be two things 1. Power supply or 2. Main board. is my initial thoughts. Have you opened it up to check the fuses, caps etc? If the power suply voltages look good its probably the main board.
I had a similar problem with my Phillips 42 in. LCD HD TV.
Here's the problem. The Power Supply Board. I opened my TV
up(warranty was up of course) and found several bad capacitors.
Phillips and several other companies were sold capacitors that although
were highly rated failed within 5 years because of a lack of
preservatives. All sorts of electronic equipment is now being effected
due to these defective capacitors.
Solutions?
1. Take it in and have it fixed
2. Open it up, check the board for faulty capacitors(bulged or leaking) Buy a new Power supply board and install it.
3. Remove PSB, remove faulty capacitors and replace with compatible new ones.
it needs service, that means using tools and meters and spare parts to find cause.
dead screen black screened at all times.?
even in HD TV antenna mode for HD TV?
or just the remote CLICKER batteries dead.
tell things that work and no not work , even LED actions.
the maker has no books on this old TV
https://jvcproducts.com/us/contact/support.html
here they are ask them>?
what rare TV. good luck fixing any RARE TV.
moved you to TELEVISION.
Return it to your place of purchase and get something else anything else you wouldn't believe how many people are having Issues with the LT series get rid of it.
Fault to the main power supply regulator section. Either it will be a separate board, or the part of main board. Check and replace damaged component/s at its main power regulator [SMPS] section circuit. Contact any service technician. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts.
http://electro-medical.blogspot.com/
It will be best to replace the power supply regulator board as card basis rather than making "Surgery" to it; which usually will make loss for both money and time. Even though you can make it right, it will cost around an amount equal to the cost of a new board; including the cost of (spare parts + service charge)
As a first step , if it is controlled via the remote, check that the remote batteries are good and that it is functioning ok. Does the tv show anything att all? If it does come on but shows nothing then it might be that the source selection is on the wrong kind of source, you can find on the remote whether this is so by going to the source menu which should probably be on digital. (I am assuming that you only have digital broadcasts where you are.
If there is no picture whatsoever ubplug the set and check whether the internal fuse(s) are ok.)