4.3No Power
WARNING
120/240 VAC terminals are located within the DVP-120, presenting a hazard to service technicians. Only qualified technicians should open the DVP-120 case and service the internal circuits. Ensure power is removed from the DVP-120 prior to servicing the unit.
The DVP-120 starts up as soon as power is applied to the microcontroller, and the DVP-120 is designed to have power continuously applied to the unit. An external indication of successful power application to the unit is the immediate operation of the Status Lamps grouped around the LCD. If the operator does not see immediate response from the status lamps, power should be checked at J4 (refer to Figure 1-2 for connector locations).
If the correct voltage is noted at J4, then the internal fuse of the DVP-120 should be investigated. The DVP-120 is protected from over-current and transient situations by the fuse at F3. AFTER removing power from the DVP-120, F3 can be checked by removing the safety cover. If necessary, replace F3 with a 5x20 mm SLO-BLO fuse with a rating of 1 Amp 250V, e.g. Littlefuse P/N 218001. Be sure to REPLACE THE SAFETY COVER on F3 before re-applying power to the DVP-120.
4.4LCD Display unreadable
It is possible that the LCD is unreadable due to temperature or aging of the control panel. If this is the case the following steps should rectify the problem:
4.4.1 Hold the MENU key for three (3) seconds.
After three seconds, the power led will turn red. After a further two seconds, the LCD backlight will also be turned off.
4.4.2 Press the UP and DOWN cursor keys to change the LCD contrast.
Each press of the UP or DOWN cursor key will change the contrast by a step in that direction. Adjust the contrast for best viewing.
4.4.3Press any other key to exit the contrast-setting mode.
4.5The Keypad does not respond (LCD shows KEYS LOCKED)
The keypad can be unlocked by holding the zero (0) key for three seconds. At which time the backlight will turn on and the display will return to normal mode..
The keypad can again be locked by holding the zero key for three seconds, until the display shows KEYS LOCKED.
4.6After a power failure
After any power failure, the user should check the system clock. While system parameters are maintained in non-volatile memory, the system clock is backed-up by a limited-capacity button cell battery. Even though the button cell can run the clock for several years, it will eventually wear out.
