amiga 600,image with lines

[ivan]

Hi, I have a problem with my friend 600 , the image shows the screen goes with vertical lines .
Anyone know what can it be?
The capacitors are changed and the composite video output , no picture only for rgb .
I tested with two wire one vga and one scart and the two leaves with vertical lines .

A greeting.

This board is.

[roy bates]

those lines are coming from the composite sync signal,im not sure there is actually a fix for that.

[Supamax]

Isn't the mainboard missing some caps (up-left zone) ?

[kipper2k]

it looks like the 470uf and the 1000uf aluminium caps are missing so that definately could cause a dirty screen image. The 2 caps below the keyboard connector appear to be a little inflated with round tops. The 1000uf cap is also missing on the composite output line (next to the yellow RCA plug)

[ivan]

This photo is of the actual plate with switched capacitors.
No picture for composite video output.
I have taken the composite sync pin 10 and comes out the same lines.
The separate vertical horizontal sync pinout 13,14 also shows lines.

[kipper2k]

Originally Posted by ivan

This photo is of the actual plate with switched capacitors.you should check voltage and capacito
No picture for composite video output.
I have taken the composite sync pin 10 and comes out the same lines.
The separate vertical horizontal sync pinout 13,14 also shows lines.

you should replace the aluminium capacitors that are missing to see if that is the problem. You won't get a picture from composite unless you replace the one close to the RCA connector

edit, just noticed updated picture showing the caps, i would not personally use through hole caps for SMD padded boards, you should check voltage and capacitance values of the replacement caps to verify they are correct

[ivan]

but if they are all changed ??

[kipper2k]

Originally Posted by ivan

but if they are all changed ??

the capacitors will have values written on them...

ie 100uf 6.3v etc, you can use old picture you posted to compare their values to what you have now... voltage can be same/higher on new ones but not lower

Also... is the TV capable of producing a clean picture, try the Amiga on a different TV/Monitor

[ivan]

I will review the values of the capacitors.
The image comes out like a dell monitor with vga cable and a lg tv with scart cable.

[ivan]

I'm using a pc atx power to feed
You can be the problem?

[jimbob]

Originally Posted by kipper2k

Also... is the TV capable of producing a clean picture, try the Amiga on a different TV/Monitor

Try this first if you can, ideally on an old CRT, that looks to me more like a scaling artefact on the LCD than a fault in the Amiga.

Do you still have no output on composite? Grab the schematic from here and start tracing continuity, (or signal if you have a scope).

http://www.amigawiki.org/dnl/schematics/A600_R2.pdf

[ivan]

No, but the composite do not care.
What I want is to eliminate rgb lines.

[jimbob]

If you have no CRT to test with, you might get an idea if the TV scaling is to blame by using different screenmodes. Load up deluxe paint and create a new image in every available screen mode. Just fill the page with a colour like the KS screen. Observe any changes in the line pattern.

I guess it's not impossible that a fault in the composite circuit could be the cause of misbehaving RGB. Your board definitely has a fault in the composite circuit, it's worth fixing for this reason even if you don't intend to use it.

[Adrian Browne]

Ive got the same thing on my a1200 via a rg2b2 scart connector. Its a panasonic telly. I think it disappears though, when I launch games in whdload. I mucked about with the amigas resolutions but no change.

[kipper2k]

just remembered that cheap quality cables can cause these lines too, mabbe also try a thicker, shorter better quality cable

[ivan]

I tested it on a Sony Trinitron CRT, and indeed the lines disappear.
I have adjusted the dell monitor pixel clock and has greatly improved the image.
thanks for the help

[supaduper]

Glad you got it sorted
This why we Amiga owners have two of everything LoL