Analogue monitor board repair

[drlegendre .]

"Hence the question - am I wasting my time without a schematic for this
analogue board?"

Might be helpful if you mentioned exactly what is or isn't wrong with the
unit.. describe the symptom(s), etc.

On Mon, Oct 31, 2016 at 1:44 PM, Adrian Graham <witchy at binarydinosaurs.co.uk
> wrote:

> Folks,
>
> I think I know the answer to this before I even ask, and that answer will
> be
> 'got a schematic' to which the answer's 'no and I doubt one exists any
> more'
> but...
>
> My recent Executel addition has a 5" screen with associated analogue board
> that seems to be powered from a display chip I can't find any info on, and
> at least one of the adjustment potentiometers has suffered metal fatigue
> and
> broken:
>
> http://www.binarydinosaurs.co.uk/STCExecutelScreenPot.jpg
> http://www.binarydinosaurs.co.uk/STCExecutelAnalogueBoard.jpg
> http://www.binarydinosaurs.co.uk/STCExecutelDisplayChip.jpg
>
> I've replaced it with a seemingly common 10K modern part that I had in my
> spares box but it's unknown whether the display worked at all prior to it
> being put in very damp storage, also the rating of the failed pot isn't
> known but the capacitor next to it is 50V.
>
> I've also removed, checked and replaced out of spec capacitors, one of them
> was a 680nF 50V radial. I could only find a 63V PET version on cpc's
> website
> and did much reading on differing capacitor types, concluding that it
> SHOULD
> be OK.
>
> Power supply is known good because it's one of my working ones, the
> original
> is still dead.
>
> Hence the question - am I wasting my time without a schematic for this
> analogue board?
>
> Cheers!
>
> --
> Adrian/Witchy
> Binary Dinosaurs creator/curator
> Www.binarydinosaurs.co.uk - the UK's biggest private home computer
> collection?
>
>
>