SG250X-48P login not possible

[powerstat]

Hello I have a SG250X-48P since some years.
I updated it from 2.5.5.x to latest version 2.5.9.54. 
After this update I had a problems with performance.

So I decided to go back to the backup image 2.5.5.x but after this I could not login anymore.

So I did a factor reset - which allows me to login via cisco/cisco.

After this I uploaded the 2.5.9.54 image again.

The result ist that I could not login any longer - also not after a factor reset.

The Web Interface ist still available at 192.168.1.254 but when entering cisco/cisco it only says Processed 10% and then jumps back to the empty login mask.

I have tried to switch it off/on and multiple factory resets without luck.

Any chance to reactivte the switch? Is there a console port inside when I open the case? Or any other tricks?

[marce1000]

   - There have been reports like this when an upgrade was done on these devices and the password contains special characters (CORRECTED)

   M.

[marce1000]

    - For instance checkout : https://community.cisco.com/t5/switches-small-business/update-to-2-5-8-12-login-problem/td-p/4463118

   M.

[powerstat]

Sorry, because of the factor reset the password and user should be "cisco", so no special character problem.

[marce1000]

 - @powerstat   That is true, there is one technical security point to think about ; what does the device think about
                         upgrades with the default password and what does it do; it's  perhaps going too far  but have a try
                         by using another simple username and password after the first factory reset, then upgrade and check
                                                if those simple credentials  (not  cisco/cisco) are still working ,

  M.

[powerstat]

@marce1000But how should I do that - there is no way in for me anymore - looks like my sg250x-48p is bricked.

[marce1000]

  - @powerstat   I can't see any solutions for the current situation neither,

  M.

[marce1000]

  - @powerstat  Something else  I was thinking about ; is the phenomenon the same with different browsers 
                         (to exclude obscure caching effects) ?

  M.

[powerstat]

@marce1000That was an interesiting hint - with firefox I had no login at all - now I tried chrome - with logs me in let me set a username and password and then hangs at processing 40%.

[powerstat]

But looks as login with chrome and the new user/passwd works. Active image now is the older 2.5.5.47

[marce1000]

 @powerstat  I assume it would be safe to do the upgrade again. If you can't login use Chrome in Incognito Mode

 M.