I got a used T-Mobile Galaxy S Blaze(SGH-T769) from Goodwill. Since it still has information on it, I am attempting to factory reset it. However, whenever I try to boot it into recovery mode, it boots into a strange screen where random bars of color show up. When I boot normally, everything works fine but it has a lockscreen so I can't do anything normally. Besides that, its rather difficult to do anything since the phone is missing its power button.
What could be the reasons for the strange behavior in recovery mode?
Are there any ways to factory reset it besides that?
Should I just give up on the phone?
UPDATE:
I bricked it... Phone won't turn on at all after following guide at https://forum.xda-developers.com/showthread.php?t=1591598, I forgot to uncheck re-partition... even more hopeless?