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DiVA Service
Issue 1.0

DV78 DVD Player

Bringing music & movies to life
Contents List

Circuit Description

Power Supply L959AY
! CCT diagram
! Component layout diagram
! Parts list

Main Board L960AY
! CCT diagram
! Component layout diagram
! Parts list

Display Board L961AY
! CCT diagram
! Component layout diagram
! Parts list

! L924TX
! L925TX

Mechanical Assembly
! Exploded view diagram
! Mechanical and packing part list
Diva Dv78 circuit description

Fig 1 PSU clock control
The DiVa DV78 is a completely new design platform
that share a similar circuit topology to the earlier Fs PSUFS1 PSUFS0 PSUCLK
released Vaddis V based players such as the Diva Frequency Pin 11 Pin 12 Output Pin 5
88+, Diva 89, DV27. select IC305a IC305a of IC305a
44.1 kHz 0 0 44.1 kHz
The player is based around acclaimed Zoran Vaddis 48 kHz 0 0 48 kHz
88.2 kHz 0 1 44.1kHz
V chipset coupled to high specification Wolfson D to A
96 kHz 0 1 48 kHz
converters for Left and Right channels. 176.4 kHz 1 0 44.1 kHz
192 kHz 1 0 48 kHz
Power supply board. Others 1 1 OFF

Non-switching The PSU sync signal is driven into the power supply via
Resistor R9 if no Sync is present the unit is set to free run x
Mains power arrives at IEC inlet socket SKT1 and is due to the RT/RC network attached to Pin 4.
filtered by EMC choke LI and Y caps C3 and C4,
mains switch SW2a/b switches both Negative and Live IC1 is running in regulated mode and monitors the voltage
phases before the power reaches the mains select output on the +5V and +3V3 D.C lines, the two voltages are
switch at location SW1 the switch allows the primary summed by TR8 and Driven into the VFB and Comp inputs
windings of the transformer TX1 to be wired in either of IC1, the Voltage is then regulated by changing the time
Parallel or Series configuration. base of the PWM output at pin 6 (longer the time base the
lower the voltage), the PWM switching frequency is driven
The Bridge rectifying Diode package at location D1 into the switch-mode transformer by the high speed Nmos
forms the basis of the conventional power stage and device at position M1, R5 is used to sense the Current
supplies a VN35V6 (-35.6v) to the Switch mode across the gate of the Nmosfet and in the event of a short
stage, transistor TR1 is biased by 2v7 Zener diode circuit will safely shut the power supply down. We derive the
DZ1 and allows for the series Zener diodes DZ2, DZ3, 12v Mech supply from the output of M1 using the Ultra-fast
DZ3 to supply the VN13V5 and VN19V rails. Diode at location D8 to rectify the PWM line.

We will also see a simple A.C present circuit this is The D.C outputs from the switch mode have extensive
used for delayed output relay operation and fast relay switch mode noise removing filters these are seen as 100n
closure under interrupted supply conditions thus caps down to ground and Wire wound inductors in series
preventing op-amp offsets from reaching the Audio with the supply rail.
output sockets.
Power supply main board
Switch mode
All the power supply rails are supplied to the main board via
The switch mode supply is formed around the the 32 way FFC connector at location CON1001.
Driver/Control chip IC1 UC3843 (used in regulating
mode). The chip is referenced the