I did not change the 3.5mfd oval cap. I was confused about if I absolutely had to use the same part or of I could put a normal cap in. Someone said it had to be the original type but so far these have proven to be expensive. $13 plus a $11 handling fee plus shipping.
The multisection has been replaced which is what brought the screen back to almost normal size. I double checked everything and it all looks good.
How would I check those parts? I figured if the rectifier was having issues the unit would not turn on, at least that's how stereo equipment behaves. As for the triac it seems to work just fine. I do have a friend with a system III that has a bad one of these but it causes no issues besides needing to have a switchable plug for it.
Oddly enough I can't find what burned. Everything looks okay so it's just a strange situation. Sometimes units burn dust but not like this.