Sony Plasma KE-42M1 -70 volt section is not stable when Y sustain board is

The 6-time blink code for the Sony KE-42TS2U indicates a backlight error. This may be due to a faulty backlight inverter board, or a problem with the power supply to the backlight inverter board. It is recommended to have the TV serviced by a qualified technician to diagnose and repair the issue.

Fault with the main power supply regulator 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://electronicshelponline.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.

Fault with the main power supply regulator 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://electronicshelponline.blogspot.com/
It will be best to replace the power supply regulator board as card basis.

this is not a capacitor problem. set is only 18 months old - has something to do with x y sustain boards not allowing smps to power on the high voltages.

7 blinks Driver SOS 2 SU / SD / SS Boards
(SC floating voltage area)
This is the fault indication meant by 7 blinks of standby light. Just visit this site 'Electro-help' Faults with plasma TVs are described in detail. Check this link and select the site. Pull up older posts there.

The main power supply regulator section circuit fault. 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. Pull up older posts.
http://electronicshelponline.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) More to say, most of the spare parts to it will be difficult to get from open electronic spare part market. This is true to most of the flat panel TV power supply boards; irrespective of its brand and screen size.

You might have a bad B board. What's worse is that the power switch is connected to the Q board which works in conjunction with the B board. Replace B board, You can send your B board for repair to a company called modus link pts. They are the largest part supplier of after market parts and repair.

i have the same problem! did you ever solve the issuE??

You most likely have a power supply problem. but the problem may not be the actual power supply. The drive cicuits for the plasma panel can load down the power supply and give you the symptoms that you are having. Without being able to be there and take voltage measurements, I'm afraid I can't narrow it down more than that. My first suspect is that one or more of the sustain boards (the boards that drive the plasma panel) have failed. That would explain the lack of display. It is likely one of 3 boards that has failed, PSU (power supply) logic (the main control board for the set) or DE2 (panel drive board). There is a chance that the panel itself is bad, but that is not the most likely cause of your problem

UPDATE:
I finally isolated the problem, the problem has to do with the Y SUSTAINER BOARD not receiving enough/necessary voltage when turned on, while initially thinking it was just the yboard was the problem, i replaced the Y sus board with no success, with only further diagnosis, i discovered the board voltages coming from the powersupply, there are 5 voltages that relate to the Y sustainer board, VA, VSC, VS, VE, VSET. they all supply a certain voltages that all have to be supply the correct voltage in order for the y sustainer board to be working, well guess what, the VA line, which for my set needs 70volts, which upon startup quickly drops from 75volts to a jumpy 8.5-9.5 volts, which of course is nowhere near the 70 volts needed, so this quick drop in voltage is directly related to the screen fade upon startup, i found the problem now the real problem is finding a replacement power supply. hope this helsp anyone with similar issues.