Return to Section TOC
Return to Section TOC
Return to Master TOC
Return to Master TOC
TROUBLESHOOTING AND REPAIR | ||
| ENCODER PC BOARD TEST (continued) |
|
FIGURE F.4 — ENCODER PC BOARD TEST.
#500
#526
J2
#516
#527
#505 #517
ENCODER
PC BOARDS
Return to Section TOC
to Section TOC
Return to Master TOC
to Master TOC
TEST PROCEDURE
1.Remove input power to the
2.Using the 5/16 in. nut driver, remove the two screws from the top of the con- trol panel.
3.Carefully lower the control panel.
4.Locate plug J2 on the control board. See Figure F.4. Do not remove the plug from the control board.
5.Apply the correct input power (42 VAC) to the
6.Carefully check for the presence of 5 VDC from 5J2 (lead #505) to 4J2 (lead #500). This is the supply voltage from the control board to both encoder boards. (Volts and WFS). If this voltage is missing or low the control board may be defective. Also make certain the 5 VDC supply is being applied to the encoder boards via leads #505 and #500. See the Wiring Diagram.
7.While slowly rotating the Volts control check for a “pulsing” 0 to 5 VDC signal from 8J2 (lead #516) to 6J2 (lead #517). If the 5 VDC supply IS present at the encoder board and the pulsing signal is NOT, the Volts encoder board may be faulty. Also check the lead and plug connections between the encoder board and the control board. See the Wiring Diagram.
8.While slowly rotating the WFS control check for a “pulsing” 0 to 5 VDC signal from 3J2 (lead #526) to 7J2 (lead #527). If the 5 VDC supply IS present at the encoder board and the pulsing signal is NOT, the WFS encoder board may be faulty. Also check the lead and plug connections between the encoder board and the control board. See the Wiring Diagram.
NOTE: “Pulsing” means that as the control is rotated the signal will fluctuate from 0 to 5 VDC.
9. Remove input power to the
Return
Return
10. Reassemble the control panel.
