2.
Remove the chassis top cover.
3.
Disconnect any cables connected to the High Voltage (HV) board and remove it from
its slot.
NOTE: Each HV board can be independently configured for positive or negative polarity.
Figure IV-4. Voltage Polarity — Location of Components.
4.
Locate component CR1 (the diode bridge). Along one side, CR1 will read:
4.1.
If the MPC is configured for positive polarity, the word POSITIVE is shown to
the left of CR1 as shown in Figure IV-4.
4.2.
If configured for negative polarity, the word NEGATIVE is shown to the right
of CR1.
5.
If a polarity change is desired, unsolder the four pins of CR1.
6.
Rotate CR1 180° and shift it to the next series of holes so that CR1 exposes the
desired polarity.
7.
Re-solder CR1 at the desired location.
8.
Next, unsolder the two polarity jumpers on the bottom-center of the HV board (Figure
IV-4), and re-solder the jumpers according to the table below.
W4 and W5
configures positive polarity
W2 and W3
configures negative polarity
9.
Reinstall the HV board and reconnect the cables.
10.
Replace the MPC top cover and reconnect power.
11.
Re-calibrate the unit. See Section 3, Running Diagnostics (page 37), the
CALIBRATION (page 40) portion.
PROM Change Procedure
The CPU board, located inside the DIGITEL MPC chassis, houses the PROM (Programmable
Read Only Memory), which contains the programmable commands for the DIGITEL MPC.
Figure IV-5 shows the PROM's location.
Digitel MPC Manual
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