SOLVED: Roomba 500 One very Peculiar not easy Problem

[Armadillo2]

This roomba has a very peculiar problem not found in all the WWW, I searched.

If I press the Clean button once;

When the Clean LED turn On Green with a Sound, the roomba can operate normally.

but for most of the time;

The LED turn Green like normal without the Sound and the roomba will refuse to move [press Clean button again] or turn itself off except Reset. There are no error tone, sound or blinking. Its like dead except the Reset which reset the ucontroller.

I swoop the MB to another machine and it still repeat the same problem so the MB is the problem, confirmed.
I am thinking that the ucontroller is waiting for something? during the startup and I don't know what's happening.

Anyone has a great idea where to begin?

Thanks to all.

[a1robotrepair]

Try cleaning the circuit board battery connectors with alcohol & rag.
Then bend them down a little.
Next would be check D46 and Q18.

[Armadillo2]

Thanks, at least there is a reply to this complex problem.....

@a1robotrepair

Hi Robot Master, thanks for reply. I have checked D46 and Q18, both are OK.
There are no problems during charging and the 5VReg buck is OK.

When it's operate normally, the robot can clean for over over 30 minutes, no problems, the connectors are cleaned.

What about U20? I remember I did swoop with a "PASI" before. Maybe I should go thru my microscope on that joints as well, when I got the time. Was a quick lazy job at it before. But I doubt it considering I can press the Clean button.

Do let me know your thoughts. Thanks for sharing.

[Armadillo2]

Thanks guys, the problem has been resolved.

Cause: Improper Reset Sequence and timing.

[leonicholson]

How do you reset a 500 series (595)?

[Armadillo2]

How do you reset a 500 series (595)?

For User application level, pressing down the Roomba’s SPOT and DOCK simultaneously for 10 seconds.