I removed the C3 Tantalum Capacitor on the Power Panel and was getting ready to replace it when I noticed the C1 nearby was fried. Can I use the same type (10µF 50V) electrolytic capacitor I'm replacing at C3 to replace the blown C1 or does the C1 need a different capacitor? Strangely, my LX200 was working fine even with the C1 blown (see below).
C1 is the ONLY capacitor that needs to be changed. There is no reason to change C3. C3 is across the 5v tightly controlled output of the voltage regulator right next to it and is well within it's 25v spec. C1 is across the +18vdc input and is the one at risk. On every board, there is 1 capacitor across the 18V input to the voltage regulator. That is the only capacitor that needs to be changed.
When C1 failed, it shorted out and then burned. When the short occured the scope would have stopped working and the odor of the burning cap would have been noticed. Fortunately the cap did not continue to burn (the fuse should have failed).
In large high power systems these capacitors can cause a full blown fire.
Please be sure you are changing the correct capacitors!