Mitsubishi WD-52627 Training Manual page 57

PWB-ENG-PWR
It was previously mentioned that the PWB-ENG-PWR
board is added in DLP models. Figure 5-7 shows this
circuitry. It is basically a PWM Regulator with a push
pull FET output circuit, generating a 2.5V supply for the
DLP Engine. The board also serves as an interface for
the 12V, 5V and 3.3V Standby supplies from PWB-
POWER.
Hard Disc 7Drive (HDD) Supply
Additional power supply circuitry is required for the
V30+ and V31 chassis. Both of these chassis types
feature a Hard Disc Drive. Added power circuitry for
the HDD is on the PWB-POWER, refer to Figure 5-8.
Note that the Fan Stop monitoring circuit for the HDD
is also added to PWB POWER.
Figure 5-6: V29/V30/V30+/V31 Fan Supplies
5-7
Power Distribution
When a specific PWB is suspected as the cause of a
problem, the following should be checked before or-
dering a new board:
• Power supply voltages supplied to the PWB.
• Signals supplied to the PWB.
Power Distribution diagrams are helpful in locating the
source of a missing power supply voltage. Figure 5-9
shows the Power Distribution for the V28 chassis. Fig-
ure 5-10 illustrates Power Distribution in the DLP chas-
sis. Although the two chassis types are similar there are
some differences. The shaded areas in Figure 5-10
indicate differences from the V28 chassis.