How to fix error 7a on a billcon d-551 - Billcon D-551 Mixed Money Counter 2 Pocket

Question edited for a lot more clarity.

Videos

https://www.google.com/search?q=Ricoh+SP-220NW+error+551

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Contact manufacturer to request assistance. http://www.billcon.com/Contact.htm

Error code 7A
A synchronized signal of the main motor cannot be detected.
Turn the power off and then back on again.
1 Flat cable connection failure of main motor
Check the flat cable connection of the main
motor and reconnect them.
2 Main motor failure Replace the main motor.
3 Low voltage power supply PCB failure
Replace the low voltage power supply PCB ASSY.
4 Main PCB failure Replace the main PCB ASSY.
Replace the main PCB ASSY.

probably fusing thermistor defective

Found manual here with all error codes. It's in Russian though..
http://www.rservice.by/files/manual/cassida/counters/Cassida%20Billcon%20N120%20User%20Manual%2028.11.2013.pdf

Hello thanks for using FixYa
Error code 7A occurs in different forms and they are linked directly to errors caused due to calculations as detected by GPU, however, it is still doubtful what exactly cause these GPU errors in hardware and the errors in WU. Keep in mind that this error code could also suggest that the main PCB is broken.

For the error code 7A to be fixed permanently, you need to ensure that the main PCB is fine and is working in good condition. If the error code is caused due to malfunctioning of the main motor, then you need to check the whole setup by connecting it with another motor. In this case, make sure that there is no mechanical load present on the main board. While fixing this error code, you will notice that the motor runs slowly initially and then picks up the speed later.

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For the error code "7a" to be fixed permanently, you need to ensure that the main PCB is fine and is working in good condition.
If the error code is caused due to malfunctioning of the main motor, then you need to check the whole setup by connecting it with another motor.
In this case, make sure that there is no mechanical load present on the main board.
While fixing this error code, you will notice that the motor runs slowly initially and then picks up the speed later.

http://www.fixya.com/support/t5660619-7a_error

For the error code "7a" to be fixed permanently, you need to ensure that the main PCB is fine and is working in good condition.
If the error code is caused due to malfunctioning of the main motor, then you need to check the whole setup by connecting it with another motor.
In this case, make sure that there is no mechanical load present on the main board.
While fixing this error code, you will notice that the motor runs slowly initially and then picks up the speed later.

http://www.fixya.com/support/t5660619-7a_error

For the error code "7a" to be fixed permanently, you need to ensure that the main PCB is fine and is working in good condition.
If the error code is caused due to malfunctioning of the main motor, then you need to check the whole setup by connecting it with another motor.
In this case, make sure that there is no mechanical load present on the main board.
While fixing this error code, you will notice that the motor runs slowly initially and then picks up the speed later.

http://www.fixya.com/support/t5660619-7a_error

For the error code "7a" to be fixed permanently, you need to ensure that the main PCB is fine and is working in good condition.
If the error code is caused due to malfunctioning of the main motor, then you need to check the whole setup by connecting it with another motor.
In this case, make sure that there is no mechanical load present on the main board.
While fixing this error code, you will notice that the motor runs slowly initially and then picks up the speed later.