I am getting interference on my CPC monitor in the form of an ever so slightly wavy screen. I have narrowed down the cause to the 5v power supply lead from the monitor to the CPC. But don't know how to fix this.
If I use an alternative 5v power source for my CPC the interference goes away.
Furthermore, I plugged the CPC into another CPC monitor but took the 5v power from the 'faulty' monitor and the problem moved to this other monitor.
So I concluded that drawing power from this 'faulty' monitor creates interference.
Any idea what could be causing this?
Prime suspect would be failing capacitors resulting in high "Hum" levels on the 5V PSU output. Monitor requires a recap...
Any idea how I can test which capacitor is faulty whilst they are still connected to the board. There are lots of them and awkward to get to.
I would replace all of the electrolyt capacitors. They will fail at a certain point in time. I have this ahead of me as well :-(
Thought I might have to :(
Thanks for the advice
Do you have another CPC to try? Because according to your description the problem could also be in the CPC. I would try to recap the CPC first, which is far more easy.
Quote from: abalore on 12:25, 27 November 22Do you have another CPC to try? Because according to your description the problem could also be in the CPC. I would try to recap the CPC first, which is far more easy.
From my understanding of the initial post - the CPC is OK when powered from the good monitors 5V output - but with the CPC Video connected to the Good monitor - but powered via the "Bad" monitors 5V Output, "Hum Bars" are visible on the good monitors display - this confirms that the issue is with the "Bad" monitors 5V power output.
If you want a "Quick fix" of the CTM640 - then I would focus on:-
C518 & C519 both (470uF / 10V). You could increase both to 1000uF 16V etc.
C520 10uF 16V
Spot on. So the cpc is good. Thanks for narrowing it down. I'll look into your advice.