Amiga Explorer

[Oldsmobile_Mike]

But the serial port was working since last week while the mouse port wasn't working before too since many years ago.

https://en.wikipedia.org/wiki/Cascading_failure

[Oldsmobile_Mike]

Anyway other way to check if the COM port is healthy or not?

http://www.bigbookofamigahardware.com/bboah/product.aspx?id=803

[Oldsmobile_Mike]

Um, you could try plugging in any other device, a modem comes to mind, and see if that works? But that won't test all the pins like specific diagnostic hardware would.

Have you tried with a different cable?

[Oldsmobile_Mike]

You already said it was working fine until it suddenly stopped. Why do you think an older version would work?

[Oldsmobile_Mike]

Would you please show me step by step?

You guys should make a YouTube video, that's what I do when folks ask for stuff like this.  Probably faster than trying to type 983457938457 words.