Sony KV-40XBR800 No Picture
 

I recently got a sony kv-40xbr800 cheap. Played two weeks but picture was weak and out of focus. I have tried replacing the two ics mcz3001db. No luck. I also replaced ic6505, transistors q5003 and q5030. Transformer 1-437-669-11, high output transformer. It still blinks twice on the front panel and no picture. I am running out of ideas.

Sadly, that sounds like the tube is gassy. Those have a circuit that prevents the video from popping on, until the cathode current is in a certain range. When the tube is weak, it will never pop on once the current is out of that range. A quick test is to VERY SLIGHTLY back down the G2 pot (on the FBT in that set? not sure), and if the picture pops on, then it pretty much confirms you have a bad CRT.

I have one here in SoCal if you need, but obviously it's not shippable.

Charles

Is the set getting high voltage, can you feel the static on the screen or hear the crackle when you turn it on?

Set will not come on. Standby circuit clicks then goes off. Diagnostic lights blinks twice.

Thinking maybe either CRT gassy, or you have a bad contact on the flyback to board. Possible reflow of the connections? I had this same set and the IC's fixed it. but if the CRT gets too tired on these sets, it will not allow HV to come up. try turning the G2 up or down.

Of course thats exactly what Charles said :p

I didn't understand that it wasn't powering up. That's different. I thought it was coming up with high voltage, and just failing to pop the video on. In this case, you probably have a power supply failure. But I'm still scared by your description of the picture being out of focus, etc. May still be a weak CRT, and this no-start may be an additional issue.

Charles

Where will i find it?