Atari ST gives blurry image now

[plane vuki]

Hello.

 

My Atari STfm was working good. I was using it with a tv-out.

Today I decided to connect it VGA monitor (CRT) for hi-res and sharp image.

Surfed around the internet, learned how to do, connected grounds to grounds, vsync to vsync, hsyne to hsync, and for a start: mono to green.

For about 10 miniutes everything was good, got hi-res and sharp image.

Then suddenly: blurry, and goes on like that. Restart: same. Mono to red/blue:same.

I thought maybe my CRT is damaged for some reason, tested with PC: everything looks good.

I thought maybe something wrong with ST, tested it with TV-out: blurry + colors are "not good".

 

Any idea what went wrong and what can be done?

I have a suspicion that not using a resistor at mono-out might have slightly damaged something inside?

 

Thanks in advance.

 

(Attached photos showing blurry image on CRT, mono to green in this case)

[plane vuki]

Update: It was still showing bad image, nothing fixed it. Then I decided to look inside for visible damage or burn on any components. Dissassembled: all look good, moral is low, feel very bad.

Assembled back, tested: everything is good again!

 

Huh what was that all about? My ST is in very good condition overall, very clean and no visible damages to anything. I have no idea why it suddenly showed blurry and after dissassembly+reassembly was back to normal. I think it wasnt due to not using resistor, but from now on I will for any case.

Why this happened I have no idea, what was the reason. Maybe some static build up? I remember it happened when my one hand was touching ST, with other hand I toiched CRT to adjust it.

 

If you have any idea please let me know.

 

But for me, lessons learned so far:

Use resistors, dont touch CRT and ST at the same time.

[ParanoidLittleMan]

It was rather some contact error, dry joint. Possible that will happen again. Cure: reseat chips in sockets (shifter), resolder especially video connector.