If the display's flat cable wasn't okay the display would simply loose sync and output no image at all

I'm now more interested in fixing the damned ISO problem since it's a console and there's no point in having a console that can't play games(even Mario Wars which is a homebrew crashes on loading with a BSOD and I think the other games do the ame but don't provide me with a BSOD and simply freeze with a black screen). So to downgrade to 1.50 I must format my MS and just leave the 1.50 EBOOT? No other files? And that will 100% not brick my PSP? Cuz I don't want to search for a second console again to revive my PSP :| I might be good at hardware but don't know a sh*t about PSP's software and am like a complete noob

Everything is absolutely new to me! I still can't figure out how to use all the things in the custom FW but am very proud with myself after discoveryng the OSD menu after holding HOME

which seems to be very usefull for testing ISO compatibility! Please excuse me if I'm getting on your nerves but can you also tell me a good video player for the PSP? It must support Cyrilic Subtitles. I am reading about some PMP format. Is this the best one? And can the build-in player handle it?
10x a lot in advance!