Sony STR DG520 - MULTI CHANNEL AV RECEIVER - Power Amplifier, DC to Dc converter schematic and adjustments

US, Canadian,AEp,and UK Models
POWER OUTPUT AND TOTAL HARMONIC DISTORTION
(Models of area code US only)
With 8 ohm loads, both channels driven, from 20 – 20,000 Hz; rated 90 watts per channel minimum RMS power, with no more than 0.09 % total harmonic distortion from 250 milliwatts to rated output.
Amplifier section
Models of area code US, CND 1)
Minimum RMS Output Power (8 ohms, 20 Hz – 20 kHz, THD 0.09%) 90 W + 90 W
Stereo Mode Output Power (8 ohms, 1 kHz, THD 1%) 100 W + 100 W
Surround Mode Output Power 2) (8 ohms, 1 kHz, THD 10%) 130 W/ch
Models of area code AEP, UK 1)
Minimum RMS Output Power (8 ohms, 20 Hz – 20 kHz, THD 0.09%) 85 W + 85 W
Stereo Mode Output Power (8 ohms, 1 kHz, THD 1%) 100 W + 100 W
Surround Mode Output Power 2) (8 ohms, 1 kHz, THD 10%) 130 W/ch
US, CND 120 V AC, 60 H
AEP, UK 230 V AC, 50/60 Hz
Video section
Inputs/Outputs
Video: 1 Vp-p/75 ohms
COMPONENT VIDEO: 
Y:1 Vp-p/75 ohms
PB/CB: 0.7 Vp-p/75 ohms
PR/CR: 0.7 Vp-p/75 ohms
80 MHz HD Pass Through
AM CHANNEL STEP 9 kHz/10 kHz SELECTION MODE (US, Canadian model only)
* Either the 9 kHz step or 10 kHz step can be selected for the AM channel step.
* Procedure:
Turn the [INPUT SELECTOR] control to set AM and press the [Power] button to turn off the main power.
While depressing the [TUNING MODE] button, press the [Power] button to turn on the main power.
Either the message “9k STEP” or “10k STEP” appears for a moment and select the desired step.
Power Amplifier and DC to DC converter schematic
VACUUM FLUORESCENT DISPLAY TEST MODE
 All fluorescent segments are tested.
When this test is activated, all segments light on at the same time, then each segment lights on one after another.
 Procedure
While depressing the [TUNING MODE] and the [DISPLAY] buttons simultaneously, press the [Power] button to turn on the main power.
 Turn the [INPUT SELECTOR] control, all segments light off.
SOUND FIELD CLEAR MODE
 The preset sound field is cleared when this mode is activated.
Use this mode before returning the product to clients upon completion of repair.
 Procedure
While depressing the [2CH] button, press the [Power] button to turn on the main power.
The message “S.F. CLR.” appears for a moment and initialization is performed.
SOFTWARE VERSION DISPLAY MODE
 The software version is displayed.
 Procedure
While depressing the [SPEAKERS (ON/OFF)] and the [DISPLAY] buttons simultaneously, press the [Power] button to turn on the main power.
The model name, destination and the software version are displayed for a moment.
KEY CHECK MODE
 Button check:  Procedure
While depressing the [SPEAKERS (ON/OFF)] and the [2CH] buttons simultaneously, press the [Power] button to turn on the main power.
Either the message “REST 13” appears.
Every pressing of any button other than the [Power] counts down the buttons. The buttons which are already counted once are not
counted again. When all buttons are pressed “REST 00” appears.
SWAP ALL MODE
 The signal will be swap to all channel so that all speaker will have sound output.
 Procedure
1. While depressing the [SPEAKERS (ON/OFF)] and the [A.F.D.] buttons simultaneously, press the power [Power] button to turn on the main power.
2. “SWAP” appears. (No change while displayed.)
SHIPMENT MODE
All preset contents are reset to the default setting.
 Procedure
1. While depressing the [SPEAKERS (ON/OFF)] and the [MUSIC] buttons simultaneously, press the power [Power] button to turn on the main power.
2. “CLEARED” appears and switch off the set.
RE-BOX CLASSIFICATION TEST MODE
 Procedure
1. While pressing the [MEMORY/ENTER] and the [INPUT MODE] buttons simultaneously, press the power [Power] button to turn on the main power.
2. “R.BOX[][][]xxx” appears.
3. xx indicates number of times set powered on.
4. Press any button or power off the set to release test mode.
DCAC FACTORY TEST MODE (AEP, UK model only)
DCAC Factory Test mode have two stages
1. DCAC DSP Data Line Checking
2. DCAC board Checking
When power off
Press the three buttons [MEMORY/ENTER] + [MOVIE] + [Power] .
“DCAC[]FTM” appears.
Afterward, press the [TUNING MODE] to start DCAC factory test mode.
DCAC DSP Data Line Checking
After press the [TUNING MODE], DCAC Factory test mode will start, below display will show:
“DCAC[][][]x” x=1, 2, 3
If there is error happen, below display will show:
“ERR[]SD0x” x=1 t D1501 or R1530 problem
x=2 t D1503 problem
x=3 t D1504 problem
2. DCAC board Checking
Connect front left speaker of the receiver and AUTO CAL microphone. Turn [MASTER VOLUME] jog, there will be test tone sound output from front left speaker, and the display will change accordingly.
“AD[]-[]xxx” xxx=0 to 255 (depends on loudness of test tone)