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Heatercathodeshort · 29th Apr 2010, 6:46 pm

Just a word of warning here. This is an early version of the V4 using the pink perspex implosion screen. The original scanning coils had the line and frame coils insulated from each other by celophane sheets, the sort sweets are wrapped in. After a period this becomes brittle with heat and turns to powder resulting in a large breakdown between the two sets of coils.This was often confused with LOPT failure and customers were very reluctant to pay further bills after tube replacement.
This usually occured when the CRT was replaced due to the disturbance of the coils themselves. Later versions and all replacement coils were insulated with polythene and remained supple and a good insulator. If you have the celophane coils there is a risk of failure and they cannot be repaired. I have two V4's with this fault!
These are great sets and give a really good black and white picture but like all complicated things in life tend to be frustrating and difficult to fault trace if you are not familiar with 'Automatic Picture Control' [Vision AGC] and line flywheel sync.
Hope you manage to sort it. Regards, John.

29th Apr 2010, 6:46 pm	#9
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: Pye v4 Just a word of warning here. This is an early version of the V4 using the pink perspex implosion screen. The original scanning coils had the line and frame coils insulated from each other by celophane sheets, the sort sweets are wrapped in. After a period this becomes brittle with heat and turns to powder resulting in a large breakdown between the two sets of coils.This was often confused with LOPT failure and customers were very reluctant to pay further bills after tube replacement. This usually occured when the CRT was replaced due to the disturbance of the coils themselves. Later versions and all replacement coils were insulated with polythene and remained supple and a good insulator. If you have the celophane coils there is a risk of failure and they cannot be repaired. I have two V4's with this fault! These are great sets and give a really good black and white picture but like all complicated things in life tend to be frustrating and difficult to fault trace if you are not familiar with 'Automatic Picture Control' [Vision AGC] and line flywheel sync. Hope you manage to sort it. Regards, John.