We also shoot sparrows with cannons here in Denmark
.... A very fitting expressions since I right now feel like shooting something
Back to the problem!
@gflorex: You are of course right that it should have been EXOS
not EXDOS. Typing error that has been corrected.
It is - unfortunately - not the cable. I am using a new - and very good - cable that judge supplied and have tried with a couple of others from retrocables. Same result.
The powersupply is also fine and I have also tested the 7805 voltage regulators to be sure that they where giving the correct 5v voltage. They give 4,98 and 4,99 so they are fine and are not causing the artefact.
I therefore turned to trying to adjusting the Nick clock - as advised by Zozo - with C43 and L2. C43 and L2 - as far as I know - starts/adjust the crystal that controls the Nick clock.
I had problems finding L2 so by mistake I at first started messing a bit around with R202. I think I have set that back to the correct value so that it outputs 2,83 voltage. And since R202 only controls the voltage to the RF modulator that should not be the cause here.
At first I adjusted C43 and R202 when the machine was on to see the effect on the picture. I did not see any effect but after doing that I turned the machine off and I lost picture.
Or to be more correct I can not see the picture. I am using an OSSC and it looks like the machine is outputting some kind of signal that at least the OSSC can not use. See examples
here and
here.
The possibilities are - as I see them - as follows:
1) I have messed to much around with R202 and fried something along the way. Not that likely since it runs to the RF output.
2) C43 (and maybe L2) is either badly out of position so that it/they does not start the crystal/Nick correctly or they are out of order.
3) I have shortcircuted something along the way - I was also planning to remove the internal speaker and therefore removed the glue under it so that it is now moving around freely with the risk of a shortcircut.
At the moment I have some limitations in error finding:
I do not own an oscilloscope. And buying one is almost as expensive as buying a new Egyptian EP
My voltagemeter broke last night - I will get a new but it will take a day or two. But for now I can not messaure anything.
I know it is a rather big thing to just buy a new machine but I must admit that the screen artifacts I have really has taken the joy out of using the EP
So either I need to be able to fix the machine or someone else - any volunteers? - has to give it a go. I will ofcourse pay for the trouble. Or else it is the Egyptian way. And as glorez states: It is always nice to have an extra EP.