Silent Scope 1 Not Boot 'Er40'(Error 40)

[waiji]

hello.
I recently bought the Silent Scope 1 PCB.
When I turn it on Nothing is displayed on the screen,
'RA-PR-CH' is displayed on the 7-segment LED, and after the memory test, 'Er40' is displayed repeatedly and does not boot.
If anyone knows what causes ER40, please help.

 

[waiji]

I find out the cause of the problem and answer it myself.
I left the power on for over 20 minutes while it was rebooting repeatedly, and then it suddenly started working.
So I suspected the capacitors and replaced all the capacitors except related to the sound.
Now boots without any problems.
Er40 seems to be caused by low voltage or bad capacitors.