Daewoo DP-42SM Service Manual page 49

3-3-2 Adjustment after assembling (PDP Module adjustment)
(1) Setting up the initial voltage and adjusting the voltage wave form of Vsetup
(2) Measuring the voltage Margin of Vs and deciding the voltage
(3) Adjusting and checking the voltage of DC/DC pack (Vsetup, Vscw, -Ve, -Vy)
(4) Adjusting the voltage wave form of Vset-down
(5) Measuring the voltage Margin of Vset-up and deciding the voltage
(6) Adjusting the wave form of final voltage
3-4. Adjusting the Board Group (Applying the Jig Set)
3-4-1. Using Tools
(1) Digital oscilloscope : More than 200MHz
(2) DVM(Digital Multimeter) : Fluke 87 or similar one
(3) Signal generator : VG-825 or similar one
(4) DC power supply
- DC power supply for Vs (1) : Should be changeable more than 0-200V/ more than 10A
- DC power supply for Va (1) : Should be changeable more than 0-100V/ more than 5A
- DC power supply for 5V (1) :Should be changeable more than 0-10V/ more than 10A
- DC-DC Convertor Jig (1) : The Jig which has voltage equivalent output of PDP42V5####
Module after taking the Vs, Va, 5V voltage.
- Voltage stability of power supply : Within
3-4-2. Connection diagram of measuring instrument and setting up the initial voltage
(1) onnection diagram of measuring instrument Refer to Fig. 8.(Connection diagram of
measuring instrument that adjusting the voltage wave form)
(2) Setting up the initial voltage Initially setting up voltage : Vcc:5V, Va:65V, Vs:190V But,
Initially setting up voltage can be changed by the set up range according to the Module s
characteristic.
3-4-3. How to Adjust
(1) Adjusting the Voltage Wave form of Vsetup
- Connect measuring instrument like the connection diagram Fig. 8.
- Turn on the power of the measuring instrument like the <Caution> item Fig. 8.
- Connect the oscilloscope probe to P4 connector (80 Pin) of Y-SUS PCB and GND.
- Turn the VR1 of Y-SUS PCB and make the A wave form Fig. 9 to be 25 5 s.
(2) Adjusting Vset-down Voltage Wave form Turn the VR2 of Y-SUS PCB and make the B
wave form Fig. 9 to be 190 5 s.
(3) Adjusting Vramp Voltage Wave form
- Connect oscilloscope Probe to the B37(Pin) of Z PCB and the GND of PCB
- Turn the VR3 of Z PCB and make the C wave form Fig. 10 to be 15 2 s. But, in case of
not setting up the Test point, produce same output and adjust wave form connect to other
pattern or parts which has no possibility of short.
1% for Vs/Va, within
-48-
Adjustment
3% for 5V