A 220 ohm resistor will work well if placed across the capacitor leads; hold it for a couple of seconds to insure it is fully discharged. To make sure the capacitor is discharged, measure the voltage with your VOM. Be sure to keep your fingers off the resistor leads themselves by holding the body of the resistor or insulating the resistor leads. Using a VOM will discharge the capacitors very slowly due to the high internal resistance, but at least you will be sure the capacitor is fully discharged when the meter reads zero volts. Don't forget to disconnect the battery first!!

A typical measurement should be between 20 and 50 ohms. If a measurement of less than 10 ohms exists, the SCR is concidered insensitive and will require a stronger pulse to gate on. If the measurement is more than 125 ohms, then the SCR is concidered too sensitive and may fire erratically on noise pulses. In either case, I would recommend replacing the SCR.

The best way is to use a pencil eraser; I generally carry a full size artist or drafting eraser. A standard pencil eraser will work but will not last very long. For best results clean the contacts of oil or grease with plain alcohol then use your eraser to put a final shine on the contacts. Abrasives will only damage the surface.

Between the heat sink and panel baseplate you will find an insulator to electrically isolate the two. By using an ohmeter, check to make sure that the insulator has not broken down. Use the highest resistance scale and measure between heatsink and baseplate; you should show infinite resistance (a total open conection).

As an example, a General Electric EV-1 control card has left and right terminal strips that connect to the control card itself. If you are taking measurements to the terminal strips, remember that there is also a connection from the terminal strip to the control card which may be defective. The EV-1 terminal strip has two small finger connections that connect to the control card. It is always a good idea to remove these strips, and using a small pair of needle nose pliers, pinch these fingers together to make sure your connections are secure.

If a fuse continues to blow that means there is a short or partially shorted circuit in the system. Even though a #8 screw will fit most fuse holders, I don't recommend using them to replace fuses.

This will only lead to overheating of the panel and cause thermal problems and premature SCR failures. Typically the bypass is used not only to increase speed but also to give the SCRs a chance to rest and cool-off.