11
Power Supply Block
The power supply is on a single board located to the left of the DVD
mechanism. This board contains both the standby and the main power
supply. The input line filter L101 and the board connectors are the only
parts that are not available.

Standby Power Supply

This power supply produces Ever 5V as long as AC is present. Ever 5V is
supplied to interface IC201 (MB85 board) and the mute transistors (AU212
board). The standby power supply consists of an oscillator and an error
regulator. The oscillator consists of switch Q121 and a control transistor
Q122. The oscillator output is applied to T102. T102’s secondary is
rectified to output Ever 5V.
Regulation
The Ever 5V voltage regulation circuit uses:
·IC202 – error detector
·PC121 – photocoupler
·Q122 – control transistor.
IC202 samples the Ever 5V output and produces a correction voltage.
Photocoupler PC121 passes the error voltage from the cold ground cir-
cuit to the hot ground side circuit. The control transistor Q122 receives
the error voltage and uses it to alter the base bias of switch Q121. The
change in bias alters the off time of the oscillator signal. This changes the
oscillator frequency. The changes in frequency affect the efficiency of the
transformer, which regulates the Ever 5V.

Main Power Supply

The main power supply works similarly to the standby supply except the
main supply is switched, handles more power and has multiple secondar-
ies.
The main power supply is switched ON by PCONT from the Interface IC
on the FR148 board. A high at PCONT enables switch Q101 to begin
oscillating. Transformer T101 produces several output voltages that are
rectified into DC for the remainder of the DVD unit.
When a shorted spindle motor driver IC802 loaded the unfused +12V
supply line, the main oscillator quit. The oscillator worked again when the
short was removed.
Regulation
The 3.3Vdc output is used to regulate the main power supply. Error
detector IC201 receives the 3.3Vdc and produces a correction voltage. If
the input voltage increases, the error detector output decreases. The
PC101 photocoupler passes the correction signal to the control transistor
Q102. Q102 adjusts the off time of the oscillator signal to correct the
3.3Vdc output the secondary. If the DVD power consumption is normal,
the remainder of the T101 outputs will be correct.

Power Consumption

The current along each supply line was measured in both the idle and the
DVD disc playback mode.
Model DVP-S530D Current Consumption
CurrentSupply line Part replaced
by Ammeter Idle Disc PB
Ever 5V L205 30ma (set off) 77mA (set on )
+12V partial PS201 196mA 198mA
+12V total L201 236mA 350-700mA
+5V PS202 281mA 305m A
+3.3V PS203 * 894mA 950mA
-12V PS204 129m A 130mA
* Use short ammeter leads or the unit will not PB the disc and the display
will not come on. The PS203 current without the display will only be
580mA.

Oscillator Frequencies

Power Supply Oscillator Frequencies
Power Supply Set Off Set On (stop mode)
Standby (Q121/D) 57.45kHz 49.65kHz
Main (Q101/C) 0 101.2kHz