The most common causes of "no raster" in these compacts are:
1) Loose crt board (this is the board at the base of the crt)
2) Bad solder joints where the yoke connector attaches to the analog board.
3) Dead 3.9uF (4.7uF in some units) nonpolar electrolytic capacitor. I don't remember how it's labeled in the SE/30, but it's C1 in the 128k/512k/Plus.
4) Flyback problem (either bad solder joints, or toasted transformer).
The vast majority of these can be fixed with ease, and at low cost, so you have a good shot at getting that gem up and running soon.
There are some general notes on troubleshooting compacts at http://68kmla.org/files/classicmac2.pdf
The SE/30 isn't covered specifically, but there are enough similarities that you'll get some idea of what's involved.
1) Loose crt board (this is the board at the base of the crt)
2) Bad solder joints where the yoke connector attaches to the analog board.
3) Dead 3.9uF (4.7uF in some units) nonpolar electrolytic capacitor. I don't remember how it's labeled in the SE/30, but it's C1 in the 128k/512k/Plus.
4) Flyback problem (either bad solder joints, or toasted transformer).
The vast majority of these can be fixed with ease, and at low cost, so you have a good shot at getting that gem up and running soon.
There are some general notes on troubleshooting compacts at http://68kmla.org/files/classicmac2.pdf
The SE/30 isn't covered specifically, but there are enough similarities that you'll get some idea of what's involved.