Ok - thanks for that.
This is a problem with your power supply board.
If there was a voltage spike (and the set was not on a surge protector) the likeliest failure is the onboard (soldered in most cases) fuse.
Another thing that can happen on these sets is premature failure of a capacitor or capacitor bank. This is typically from poor circulation, and overheating. And is evident by swollen, ruptured, or burned capacitors - resulting in them not being able to store the proper voltages to power up the set.
The "GOOD" news is that this is one of the cheapest repairs possible on your set.
Most shops will have a $40 (or so) diagnostic fee. This is the cost to disassemble the unit and check voltages and integrity of the circuits. Once you are presented with a quote - and repair the set - the diagnostic fee is deducted from the bill.
Other shops have a $200 flat rate repair for power supply failure. This includes the components necessary to repair your board. If your board is un-repairable (burned/cracked traces etc) look at spending another $70-$150 on a replacement power supply depending if new, used, or refurbish board is sourced. (See an example HERE
The part number for the power supply is PSPF561A01A
but there are a few different revisions - so the board must be checked to match it exactly.
You can see one fuse in the following picture of the SUB power filter board. (white under plug port)
If you have additional - Just Ask.
P.S. If you're capable of removing the power supply - CLICK HERE for an eBay seller that will repair your board for about $100. Might be even cheaper locally - if you only take in the power supply to have repaired.