You might now have a parts unit, and a reference board at least for the non corroded areas.
register is right about the SE/30 power supply having a minimum load specification, but hard to say if any damage resulted from this one instance however.
Some might get the impression that replacing the capacitors is some kind of magic fix. The reality is that all the damage caused by capacitor fluid leakage must be located and reversed also, and some of this is shorts under connector bodies and ICs, as well as pads, feedthrus, and surface traces that have corroded away. The best candidates for cap jobs are those that show at most wetness but no corrosion of pads and traces. To do a good repair on a seriously corroded board, it's best to have a reference board, not necessarily working, so you can see where the traces once were that need to be put back. Even after doing all of this, there has been at least one case where the same screen symptoms were due to bad video ram, not caps.
C8 (and solder side ceramic C48) are bypass caps to ground for -5V from J12-6.
It is possible you made no wiring mistakes and one of the replacement caps is shorted. Temporarily lifting one leg of each might allow you to isolate it. Powering up with no caps is okay for shorts elimination purposes, but do not expect the computer logic to run consistently. But judging from the look of the C8, C9 area photo, there appears to be a possibly corroded area that might contain shorts. Where there is surface corrosion, the area between conductors needs to be mechanically scraped clean down to bare board to eliminate shorts that can be difficult to see even with a stereomicroscope. Toothbrushing and alcohol wipes are not enough because the short is plated thin film metal and other insoluble metal compounds. J12 itself might have corrosion underneath the nylon housing, look carefully with magnification from the sides.
+12V J12-14
+5V J12-12,13
-12V J12-7
-5V J12-6
GND J12-1,2,3,4,5,8
Video J12-9
Hsync J12-10
Vsync J12-11
register is right about the SE/30 power supply having a minimum load specification, but hard to say if any damage resulted from this one instance however.
Some might get the impression that replacing the capacitors is some kind of magic fix. The reality is that all the damage caused by capacitor fluid leakage must be located and reversed also, and some of this is shorts under connector bodies and ICs, as well as pads, feedthrus, and surface traces that have corroded away. The best candidates for cap jobs are those that show at most wetness but no corrosion of pads and traces. To do a good repair on a seriously corroded board, it's best to have a reference board, not necessarily working, so you can see where the traces once were that need to be put back. Even after doing all of this, there has been at least one case where the same screen symptoms were due to bad video ram, not caps.
C8 (and solder side ceramic C48) are bypass caps to ground for -5V from J12-6.
It is possible you made no wiring mistakes and one of the replacement caps is shorted. Temporarily lifting one leg of each might allow you to isolate it. Powering up with no caps is okay for shorts elimination purposes, but do not expect the computer logic to run consistently. But judging from the look of the C8, C9 area photo, there appears to be a possibly corroded area that might contain shorts. Where there is surface corrosion, the area between conductors needs to be mechanically scraped clean down to bare board to eliminate shorts that can be difficult to see even with a stereomicroscope. Toothbrushing and alcohol wipes are not enough because the short is plated thin film metal and other insoluble metal compounds. J12 itself might have corrosion underneath the nylon housing, look carefully with magnification from the sides.
+12V J12-14
+5V J12-12,13
-12V J12-7
-5V J12-6
GND J12-1,2,3,4,5,8
Video J12-9
Hsync J12-10
Vsync J12-11