Blue line flashing - Epson Perfection v600

check the inverter and the power supply for bad capacitors!

Remove the HDD and test, replace if necessary.

Go to a unused video input and examine the screen----if you see blue with slightly curved trace lines the blue screen control for the set is set just a bit too high.

You have two problems: blue lines is convergence problem and the blue screen and shutdown is Blue Screen control is up too high.

defective DM assembly

When it flashes blue, are the flashes bright blue lines going across the screen with the picture in the background, if so, It sounds like the Blue tube or blue driver circuit is breaking down after a short period of time. If this is the case, the uPC that controls the set is detecting a large current drain on and is shutting the set off for protection, An engineers expert eye is required I`m afraid. Ian.

TV will need service soon, blue CRT is on its way out, will need replacing

sounds like bad capacitors on the FMT board need replacing that is a common fault with the first generation DLPs There are 3 bad capacitors.

The tech is correct about the internal short inside the blue CRT. There is a way to remove that short by applying a small amount of current to burn the short but that might damage the CRT even more. At this point the CRT needs to be replace.
I will post the instructions on how to remove that short but you will need to have a good regulated power supply and limit the amount of current to 1 to 2 amps.

It sounds as though you may have a faulty lcd. Replace lcd(screen) and see if it solves the problem