Tally T6215, Руководство по обслуживанию, Страница: 61 / 164

Chapter 3. Faults and Troubleshooting
3–17
Troubleshooting The Hammer Driver Transistors
The Hammer Driver Transistors are located on the Engine Controller Board. When you are
having problems like Hammer Coil shorting or Hammers not firing, these components
should be checked along with the other components involved in the function.
To check the Hammer Driver for the malfunctioning hammer, use an Ohmmeter on its
lowest scale. Test the collector (C) to base (B) by placing the Positive (+) lead on the
collector terminal and the Negative ( – or Common) lead on the base terminal. If the
reading is either a short (0 Ohms) or an open (
∞
, infinity), the driver is bad and you should
replace the Engine Controller Board. If this check is OK, then test the base (B) to emitter (E)
by placing the positive (+) lead on the base terminal and the negative (– or Common) lead
on the emitter terminal. If the reading is either a short (0 Ohms) or an open (
∞
, infinity),
the driver is bad and you should replace the Engine Controller Board. Use the schematics
for the Engine Controller Board in the back of this manual to locate the correct driver
terminals to check for the hammer(s) you are having trouble with.
The Base of each segment of the driver goes to the LSI Chip, which turns On/
Off each segment. The Collector of each driver segment is connected to the
corresponding Hammer Coil.