Sony 53XBR45 Turn-On Issue

[garycase2001]

I have a Sony 53XBR45 that works perfectly ... outstanding picture, all remote functions work, etc. => it's as good as when we bought it new in '97 EXCEPT for one annoying attribute:

When turned on, the light will blink for a LONG time before the set comes on (sometimes 15 seconds; sometimes several minutes). It usually helps to just power off/on several times (I always wait a second between keypresses) ==> but it can still take a good while to get the TV on. Once on ... it's perfect ==> and remains that way as long as it's on (I often just leave it on all day ... and have left it on as long as 3 days).

This TV has such a great picture I hate to toss it (it's not our primary TV any more; but it actually has a better SDTV picture than my 50" Plasma or my 67" DLP) => but it would be nice if I could fix the turn-on issue.

[lcaillo]

Your problem is easy to identify, not easy to correct. Sony sets have had auto bias circuits for years, and yours does as well. I actually had this same set for a while. The way they work is by sending a pulse out in the vertical interval ( the part that you can't normally see at the top of the pix) in each crt, then measuring the return voltage of that pulse. The video processor then adjusts the gain of each CRT to have the correct relative voltage for each tube. The result is pretty good color as the tubes age, where sets without this will shift gray scale pretty severely. As the tubes age, it takes longer for them to warm up and balance out. Your Sony blanks the video until it can achieve proper balance. Eventually, when one of the tubes gets far enough out, it will just never display a pix. The bottom line is that your tubes are aging and it will be time for a new set before long.

There are a couple of potential patches for the blanking. One is to try adjusting the screen (G2) controls up a bit. You have to be careful because going too far will introduce retrace lines and prevent producing blacks. It will also likely alter your gray scale and this has to be readjusted in the service menu. The procedure is to switch to an input with no video signal and turn up each G2 control until you see retrace lines, then back it off until the screen is black. Then adjust the gray scale in the service menu.

The other potential solutions are to restore or rejuvenate the tubes, defeat the blanking circuit, or increase the filament voltage to get more output from the weak gun(s). Restoration is very tricky and should only be done by someone who has a very good CRT restoration unit and is very experienced with these tubes. It can easily make the situation worse or finish off a weak tube. Defeating the blanking circuit is possible but nearly always results in color problems and is not an acceptable choice, IME. Increasing the filament voltage is risky because it causes much more heat in the filament and cathode and can work well, but you risk burning out the filament or acceleration of the aging of the cathode. If there is sufficient cathode emitter material left, a combination of gentle restoration and filament voltage tweaking can extend the life of the set, but it will likely need regular gray scale adjustment until the tubes get to the point where they just won't produce a good pix. None of this is practical unless you are a serious DIYer, because you have to keep tweaking the set as the tubes age out.

Start looking for a new set...

[botcher]

Once I get my 53XBR's convergence fixed, it also looks like my set is not as focused as it once was. It seems to look better the longer its on, but is there a focus adjustment inside somewhere like the older small one-crt sets, or is there separate focus adjustments for each RGB tube?

Botcher