30-10-2016, 07:33 PM
(This post was last modified: 30-10-2016, 07:36 PM by Geordie McBoyne.)
Later Saturday evening the Cossor TV developed a timebase fault. It's likely one of the triode CRT horizontal deflection plate drivers has failed.
The line timebase has two shift controls, under this fault condition only one works. I might be lucky and find one of the 5megohm stand off resistors has gone high value or OC.
The second attached picture shows the fault condition. The first picture shows the components associated with the CRT grid and cathode. Note the selenium rectifiers used for picture DC restoration and also the glass spark gaps.
DFWB.
The line timebase has two shift controls, under this fault condition only one works. I might be lucky and find one of the 5megohm stand off resistors has gone high value or OC.
The second attached picture shows the fault condition. The first picture shows the components associated with the CRT grid and cathode. Note the selenium rectifiers used for picture DC restoration and also the glass spark gaps.
DFWB.
