When i turned on the TV it would come on normally but then as soon as the screen came up it would turn blue with what looked like retrace lines then bright white then black with sound intac and flash a diagnostic code of 7 blinks, marked and adjusted the focus block then Turned it on and to my amazement it turns on and looked half decent the blue tube didnt arc and i didnt get any blinking codes after a bit of fine adjustment of all of the G2 or screen and focus on the focus block the picture looks great.Now i have a 65" NOT BAD FOR FREE.....The fix? could have been a corroded pin on the CRT or bad connection from the focus block.
I have seen this before, it is a bad spot in the focus block, i am not sure i followed that correctly but in my experience with this problem it comes down to three issues, the driver on the neck module, shorted blue tube, or a focus block with a bad spot on it. The most common is the focus block, it is best to change it because after a period of time it will happen again in that new location. it could last a year or less like this.
Another thing on that 5 blink the ik or akb. This is a tricky one. ik is a circuit that measures the current flow through the cathode of the crt, this monitors how strong the electron beam is. This can be translated to white balance. with all colors being equal all three crt's should draw the same current. If one of the crt;s become weak or out of balance with the other it will blink 5 times and blank the picture and/or shut the set off. By adjusting the g2 on only one or two crt's without regard to the other one you can throw this error. A more common way to get this error is if one of your crt's are weak, if someone is getting a 5 blink error without changing the g2 the most likely cause is a bad crt.