Saturday, May 14, 2016

Sony AV Receiver – Sony STR-DG910 – Test mode - How to test the VFD – How to check the software version – How to test the function of key – FM tuner test – Power amplifier circuit diagram – Using transistor MN2466 – MP1620 - AV receiver repair and service

Sony STR-DG910

TEST MODE
AM CHANNEL STEP 9 kHz/10 kHz SELECTION MODE (US, Canadian, E2 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.
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
 1. ALL segments light on.
[MULTI CHANNEL DECODING] LED light on.
2. Turn the [INPUT SELECTOR] control, confirm display.
[MULTI CHANNEL DECODING] LED light off.
3. Turn the [INPUT SELECTOR] control, confirm display.
[MULTI CHANNEL DECODING] LED light on.
4. Turn the [INPUT SELECTOR] control, all segments and LED 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 OFF/A/B/A+B] 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 OFF/A/B/A+B] and the [2CH] buttons simultaneously, press the POWER button to turn on the main power.
Either the message “REST 15” 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 OFF/A/B/A+B] 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 OFF/A/B/A+B] and the [MUSIC] buttons simultaneously, press the power POWER button to turn on the main power.
2. “CLEARED” appears and switch off the set.
DCAC TEST MODE
1. When power off:
Press the three buttons [TONE MODE] + [2CH] + POWER .
“MIC ON” appears.
2. Plug in DCAC MIC and test sound output from front speaker
FM TUNER CHECK
FM AUTO STOP CHECK
(1) Turn on the set.
(2) Input the following signal from Signal Generator to FM antenna input directly.
Carrier Frequency: A=87.5 MHz, B=98 MHz, C=108 MHz
Deviation : 75 kHz
Modulation : 1 kHz
ANT input : 35 dBu (EMF)
(Note)
Please use 75 ohm “coaxial cable” to connect SG and the set. You cannot use video cable for checking.
Please use SG whose output impedance is 75 ohm.
(3) Set to FM tuner function and scan the input FM signal with automatic scanning.
(4) Confirm that input Frequency of A, B and C are detected and automatic scanning stops.
The stop of automatic scanning means “The station signal is received in good condition.”