commodore 1084 repair

[mechy]

Most the time its cracked/cold solder joints on the flyback transformer.The 1942 is notorious for having the chokes soldered badly and flyback solder thats bad..other times may be a flyback thats arcing. there are other causes,but these i have seen alot.

Sadly most people run them glitching and smack the hell out of them to attempt to make them act right until it either kills the fets/transformer or burns something up. I was given a old 1960 multisync that had a 1/2" hole burned thru the board in the middle and the fet literally crumbled to dust when i went to remove it.Being a crazy fool who hates to toss anything,i made a attempt at fixing it,and I managed to get this monitor going,but still has bad 15khz screen,oddly works perfect on 31khz..oh well can't win them all  as usual BEWARE OF THE HIGH VOLTAGES INSIDE!

Btw,i guess u meant a 1902(c64 monitor?) they have the same troubles usually.

mike

[mechy]

Well looking around it looks like the i301 vertical ic is bad. Anyone else concur?

that is sure a possibility, but it makes me ask what caused it to fail suddenly?,you may have other problems causing it and adding another vertical ic may just fry again..soldering the flyback etc shouldn't do that? u kill it with static or just a fluke it died? you bridge some solder somewhere that shorted it?
I really don't know enough about monitor repair to help much.

As robertB said,ray carlsen is a good guy,you might email and ask some questions,he's pretty friendly.

Mike