Hello all techfreaks out there,

I was given a Beovision Avant 28" MK III/IV. After plugging it in the sound came on but he picture stayed a white vertical stripe e.g. curtains do not open.

I am a complete B&o novice and am sure that there is nothing dramatically wrong with the telly. I rather assume the operator is faulty:-).

Has anybody got a good suggestion?

Thanks in advance

Matt

Hi:

Don't know what but there is something technically wrong with it, not operator error. Please be aware that these are not economical to repair if tube related and in which case you would be best off canabalising it for parts and throwing it away.

Graham

Hi there = It looks like the Horizontal Scan has failed.  There are several circuit failures that could be responsible for this - some of which could be expensive, some not so!  A common cause of this fault is failure of the Line O/P transistor (not very expensive to replace) or the Line O/P Transformer (expensive).  There are several other areas of circuitry that could be at fault, also.  Note that if it was a horizontal line across the screen, then it would have been Vertical Scan failure!  Are you able to do any in-circuit checks?  Have you any technical knowledge of TVs?  If you have, we may be able to give you some guidance for repair.  If not, it may be worth having a TV engineer look at it.  Meantime I'll have a look at the Service Manual (if I can get it up) = Brian (Northumberland)

Matt = Sorry about this, but I am unable to download the Service Manual pdf so havn't been able to work out this curtains gizmo - I thought it might have been derived somehow from the line scan circuit.  Back to the drawing board! Sorry = Brian (Northumberland)

Hi Matt, with a scope (oscilloscope) and some tech tv knowledge you can do something but do you have these ?? :)

In any case: it's either the scan part (not caused by a defective tube, that doesn't give this result, nor by a defective Line transformer as there wouldn't be any HT and no picture at all) or it's in the video part which, if i'm not mistaken, does the curtain part.

The start would be checking the deflection signals present on the deflection coils, a likely cause if there's something wrong here is a broken cap.