Wednesday, January 25, 2017

Denon AV Receiver – Denon AVR-1908 - AVR-788 – How to initialize the AVR – How to adjusted the Idle current

Initializing Procedure 
AV SURROUND RECEIVER/AMPLIFIER initialization should be performed when the Micom, peripheral parts of Micom, and Digital P.W.B. are replaced.
1. Switch off the unit.
2. Hold the following SPEAKERS-A button and SPEAKERSB button, and switch on the unit.
3. Check that the entire display is flashing with an interval of about 1 second, and release your fingers from the 2 buttons and the microprocessor will be initialized.
TEST MODE
Micom/DSP Error Display Mode
Micom version display mode:
When the following conditions are satisfied at its starting state, error information is displayed before version information.
Starting method:
E3,EUT,E1C model
While pressing 2 buttons, "STATUS" and "DIMMER", turn on on/off button.
Then, press "STATUS" button to display the information on the FL Display.
E2,E2A model
While pressing 2 buttons, "RT" and "PTY", turn on on/off button.
Then, press "RT" button to display the information on the FL Display.
ADJUSTMENT
Audio Section
Idling Current
Required measurement equipment: DC Voltmeter
1. Preparation
(1) Avoid direct blow from an air conditioner or an electric fan, and adjust the unit at normal room temperature 15 Degree C > 30 Degree C (59 F > 86 F).
(2) Presetting
# POWER (Power source switch) OFF
# SPEAKER (Speaker terminal) No load
(Do not connect speaker, dummy resistor, etc.)
2. Adjustment
(1) Remove top cover and set VR101 FL, FR, C, SL, SR, on Main Amp. Unit, VR401, VR402 on 2ch- Amp. Unit at fully counterclockwise  position.
(2) Connect DC Voltmeter to test points (FRONT-Lch: TP101, FRONT-Rch: TP105, CENTER ch: TP103, SURROUND-Lch: TP102, SURROUND-Rch: TP104, SURROUND-BACK Lch: TP401, SURROUND-BACK Rch: TP402)
(3) Connect power cord to AC Line, and turn power switch "ON".
(4) Presetting.
MASTER VOLUME : "---" counterclockwise ( min.)
SPEAKER (Speaker terminal) : No load
(Do not connect speaker, dummy resistor, etc.)
MODE : 7CH STEREO
Function mode : CD
(5) Within 2 minutes after the power on, turn VR101 clock wise to adjust the TEST POINT voltage to 1.5 mV ± 0.5 mV DC
(6) After 10 minutes from the preset above, turn VR101 to set the voltage to 2.0 mV ± 0.5 mV DC.
(7) Adjust the Variable Resistors of other channels in the same way.