[Q] Samsung Galaxy S2 GT-I9100 Boot loop (soft brick?) topic

Hello all, I recently had a problem with my Samsung Galaxy S2 GT-I9100, I installed CM11 on it, but It had some bugs, and I bought Galaxy Alpha, so I wanted to give it to my mother, but since she is used to TouchWiz phones, I installed 4.1.2 JB ROM, but device is stuck on boot loop because flash failed? I want to get into recovery, but I have a bit of problem..... , I dropped my phone 4 weeks before this happened, and I replaced shattered screen, but unfortunately I lost power button, and that metal plate is destroyed by pencil I used to lock the device, now I can't boot into recovery, tired combo with download mode reset and vol up + home button, nothing, just samsung logo and boot loop continues, so I tried with adb, but devices recovery is not supported, because I flashed CMR 6.0.5 (that is newest version for GT-I9100) but black screen on boot appeared, so I finally flashed stock rom for the last time 5 hrs ago and nothing, evrything is stock and chache memory also dalvik chache is not deleted, so how can I delete that so I can finally turn device on and set it up? Im not pro\ with Android, just enthusiast so I am mad on myself for doing that, I do not want to waste working device, just how can I delete chache, or can I even fix the phone??