ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Hello!This problem seems to be common due to B&O's "security protection" that detects failure somewhere. It all started with a friend having "ghosting-effects" in the picture that would come and go. It had a faint white shadow next to text for example. So we decided to replace all the caps on some boards inside because he also wanted it to last longer after this.
So I replaced all the electrolytic caps on board 04, 13, 14 and 41. I hooked it all back up and now the TV won't come out of stand-by I get a red light, but when I'm trying to turn it on, I only get green lights at the bottom for a brief moment, the TV degausses and I hear a faint squint somewhere in the circuitry.I've read all the old archived threads about this problem. I followed this great thread for sure!
First I thought the TR33 was bad since I thought it was a normal NPN transistor but it has an extra diode between Collector and Emitter (too avoid spikes?) and a resistor (?) between Base and Emitter inside. Bought a new one and it measured out the same. My mistake!
But then I saw a broken trace and it looks like it popped right of.
See imageThis trace goes to to pin 9 on connector P18. I can't recall screwing that one up like that because getting a trace to pop off like that, takes some effort.
I fixed the broken trace, hooked it all up again but same thing. So I looked at the service manual and you can check (by connecting the service mode pins at the back) if it's a power failure (Orange light) or a I2C buss error (Red light). I didn't get a orange light so I really don't know what to check next?
I haven't measured voltages yet though. I will probably get a better clue of what the problem is if I do.
So does anyone have any tips what I could check again or measure to get it up and running?
UPDATE:Turns out, I made a mistake replacing a cap on board 13, it was a little to big to fit so when I assembled the chassie boards it shorted to a diode that was in line with pin 9 on connector 18. Redid the cap to fit much better. Solved the short. Then I noticed I had connected a plug on the wrong board. It was the same pinout and fitted so I thought it was on the right place but the opposite board had the same connecter AND I had made marking on the connector showing where to place it. My mistake again. After that the TV turned on and I saw I beautiful picture.
Good job!
Martin
Also, If anyone is having ghosting issue, lika a white faint shadow next to objects and texts. Try checking the cap called C4 on the neckboard. Mine was loose but looked ok. Resolder it and the ghosting went away.When you remove the chassieboard PCB 04 (power supply) the neckboard comes with it since the flyback is connected to both. The neckboard will jump around, fall, knock into your desk when moving the cables around. Ziptie it to the frame to prevent it from moving around while working on the board. That will probably prevent these kind of problems in the future for anyone dumb enough to repair these old CRT like me :P