How to enter service mode Pioneer Elite SC37, SC35 and SC1525K AV receiver – how to check the Amp section, How to back-up and save the setting

SERVICE MODE

During Standby mode, simultaneously press and hold “MULTI-ZONE ON/OFF” and “ENTER” keys for 5 seconds to enter this mode.

How to Exit the service mode

Turn off the power to this unit by setting the main volume level to “---dB” and Multi-zone to “OFF”.
UPDATE PANEL Mode (Version update)
1. Copy the UPDATE FILE to the root directory of the USB Memory.
Note: NEVER copy several UPDATE FILES to the root directory of the USB Memory.
Copy only the corresponding UPDATE FILE.

2. Turn off the power to this unit by setting Multi-Zone to "OFF".
3. Connect the USB Memory to the USB terminal of the front panel.

4. While holding down "TUNE UP" key on the front panel, press "STANDBY ON/OFF" key and moves to the UPDATE PANEL mode.  Display will show booting id completed. 

5. Using TUNE UP/DOWN Key select "Update"

6. Pressing Enter Key enter to Update menu.

7. Using PRESET +/ - key Select "Yes".

8. Press Enter Key to continue the Update.

Update time is fluctuated by contents of the update. It will take about 15 minutes at the maximum. (Actual time is from 2 minutes to 12 minutes.)

Amplifier fault Diagnosis without Current Applied

The most common symptom of the power amplifier failure is the destruction of the power amplifier output stage or the power amplifier power circuit due to the heavy load, which is, for example, caused by short of the speaker terminal or the use of the non-guaranteed low impedance speaker.
If the protection circuit immediately shuts it down immediately after the current is applied, it is highly likely that it is the above symptom.
The procedure to diagnose/repair without applying current is shown below.

Before starting the diagnosis, wait for three minutes until the electricity is discharged.
1.Check that the MOSFET is not shorted (Ex.) Q4100, Q4101
2.Check that the gate resistance is not damaged (Ex.) R4148, R4149
3.Check that the gate diode is not damaged (Ex.) D4101, D4102
4.Check that the gate drive transistor is not damaged (Ex.) Q4102, Q4103, Q4104, Q4105
5.Diagnosis of the output stage power supply.
6.Check that the fuses FU61 and FU62 are not burned out
7.Check that the transistors Q7300 and Q7301 are not damaged
8.Check that the diodes D7308 and D7310 are not damaged
9.Diagnosis of the driver power supply.
10.Check that the fuse FU15 is not burned out
11.Diagnosis of the power amplifier drive circuit (The example below uses the wiring No. of FLch) (When the driver power supply has an error, it is suspected that the power amplifier drive circuit also has an error)
12.Check that the driver IC is not damaged (IC4101)
13.Check that the L and R connected in series to the power supply are not damaged (L4104, R4147).

HOW TO SAVE AND LOAD THE SETTINGS USING BACKUP FUNCTION WITH USB MEMORY
This model is capable of saving the set values stored in the MAIN Ucom of DIGITAL MAIN Board in the USB and loading them in a new DIGITAL MAIN Board.
(Note that MAIN Ucom should normally operate to enable this function.)
When replacing DIGITAL MAIN Board execute the above mentioned processes.

Data that can be saved/cannot be saved
The following data can not be saved. Data other than these can be saved.

Contents to save	Destination to save
Last memory for turning ON/OFF the Main power and power supply for ZONE2 and ZONE3 Last memory for inputting the Main power, ZONE2 and ZONE3 Setting for controlling HDMI Remote control ID Setting for RF remote control (EXPANSION Setup) Setting for Network Standby Data to be save upon the operation of protection circuit	EVENT Ucom
Settings for HMG (Only for SC-37, SC-LX83 system: Because BridgeCo is used.) Preset Memory, Favorite, Recently played, etc.	BridgeCo IC

(As the data saved by EVENT Ucom is on the DISPLAY Board, the data cannot be deleted unless Board is replaced at the same time.)
Requirements for USB memory
USB memory to be used should meet the following requirements.
# Compatible with USB Mass storage Class
# With a file system of FAT(FAT32)
File saving format
Files are to be saved in the following format: Model number_backup version.extension(avr)
Example: SC-37_BK01.avr
How to save in the USB memory from AV amplifier
1. Insert the usable USB memory into the USB terminal when the main device is off.
2. Enter the SERVICE MODE and select [USB BAK HOLD ] with UP AND DOWN ARROW keys.
3. Select [USB BAK SAVE? ] with LEFT AND RIGHT ARROW keys and press [ENTER].
4. Saving in the USB starts and the main device automatically goes off after the normal completion ([COMPLETE] is displayed.).
5. Remove the USB and saving is finished.
A. If the following errors occur after "SAVE" is executed, error message will be displayed and "SAVE" will be stopped and the power will be turned off.
# Ejecting of USB device
# Short capacity of USB device
# Error during writing in the USB device (Read Only or defective Sector, etc.)
B. If the same file name exists in the USB, overwriting will be automatically executed.

How to write into AV amplifier from the USB memory

1. Insert the USB with the saved file into the USB terminal when the main device is off.
2. Enter the TEST MODE and select [USB BAK HOLD ] with UP AND DOWN keys.
3. Select [USB BAK LOAD? ] with LEFT AND RIGHT  keys and press [ENTER].
4. Saving in the main device starts and it automatically goes off after the normal completion ([COMPLETE] is displayed.).
5. Remove the USB and loading is finished.
If the following errors occur after "LOAD" is executed, error message will be displayed and "LOAD" will be stopped and the power will be turned off.
# No setting file
# Mismatching between the setting file and the specification of the A/V RECEIVER type to be loaded back
# Error due to Checksum, Signature Check, and Size Check
# Ejecting of USB device (during reading of the setting file)