[1] IIRC the colour montor had RGB inputs each
one of which could be
pulled hihg. pulled low, or left floating giving a rather unuusal 27
hardware colours.
On the subject of the Color Monitor that was used with the CPC464, I am
looking for a replacement EHT transformer.
The monitor is the color one with the 5v cable to supply power to the
CPC464.
I have looked in my pile of Amstrad service manuals. I can't find one for
the CPC454, but I have found the CPC6128 one + update. And the one for
the 464+/6128+
Anyway, I have serive data on the CTM644 colour monitor, which is
probably much the same as yours. It has +5V and +12V outputs to power the
computer.
The Line oputput transformer is given the number 3714004 (Amstrad part
number 170467). I doubt you'll still get one from Amstrad, but there
might be an equivalent from some 3rd party manufacturer, particularly if
it was also used in a TV.
Be warned, though. Some years ago I needed a line output transformer for
an Amstrad VGA monitor. I was sold an 'equivalent' from one of the
well-known manufactuers. Fortunately I checked the connections before
fitting it -- if I'd fitted it the 100V (or so) HT (B+) rail would have
been connected to the CRT heater. I did get the exact Amstrad part in the
end (from CPC IIRC), but it wasn't cheap (probably cost me more than a
replacement monitor, but you know my views on repairing things).
The unit had a failed LOP Transistor (Which I have replaced), but the
160V rail is still being dragged down, and I have no EHT on the anode
cap - I have removed all the secondary loads from the EHT, so I am
Have you checked the horizontal yoke, yoke coupling capacitor (C429),
tuning capacitors (C431, C432), etc.
-tony