The service manual says on the error codes:

88-2B: RGB video processor

8C-2C: Deflection processor (HOP)

Still does not make any sense to me. Any help would be appreciated (I am not ready to buy a new telly yet!).

Thanks,

Bieele 

I reduced the voltage to the tube; this way the blacks look perfect again.

Hooked up the digital-tv box and have decided to give it another try (I did not feel confident enough to hook-up the BL's). So far (1 hour) it works fine.

I am desperately waiting for you experts to answer the questions in my previous posts!

Bieele 

What voltage to the tube did you lower ??

On itself a 'dying' avant shouldn't damage any peripherals (the worst thing could be the 'bang' in the speakers because of the sudden switch-off but i don't know if that also occurs on the powerlink outputs).

From your description i'd say the tube is suspected, you can easily find out by tapping (with the rear end of a toothbrush or so) on the tube neck and see if the picture shows colour changes etc.

Do this only when you know what you're doing in order not to break the glass !!

Thanks for the information. 

With resect to your question: I adjusted the G2 voltage; thisway the blue lines disappeared and the blacks got really black again. To do this I had to turn the potentiometer only a very tiny bit.

You are correct about the 'Bang', currently I have not connected any speakers and the center speaker alone can already produce quite a scary 'bang'.

Bieele 

'You live and you learn':....was working on a broken Avant 8420 with a suspected tube, it has the 'green fog' and stripes.

However, tapping didn't have any influence at all and the picture itself is still exellent...(many times with a bad tube it's not ok).

The better option for a good diagnose i guess is just to swap the cathode connections of 2 colours, by doing so i found out it is the tube after all.

So it seems not all faulty tubes are sensitive to 'tapping' it.... :)