is there way to fix that shakin screen of psp?

hi all memmbers ,,
well few days back my friend did buy 1 cheap psp from 1 guy he met while walking on street .... he gave it to me to make it installed with custom fw so he could play too n for that i did install 3.900mm3 on his psp..that time the psp was wrorkin fine n every thing was normal but today my frind brought back his psp to me n said that his psp after srarting the bootscreen of psp becomes slow n when he moves on screeen left or right so it takes times to move n even it gives error while formatting the memmory stick n loadin the umd takes long time aswelll so i thoght that if i install new custome fw will make a change but after installin 5.00mm 4 on it shows the same prob so is there any way to fix that thanks :)...
well when it load the bootscreen after that screen seems to b shakin in next 5 seconds n gets slow so have any 1 experinced that before ?

well the prob is fixed by me now after opening the thread n the prob was in M33 vsh Menu setting done wrong by some 1 else in first place so i did chage the Cpu clock xmb to 333/166 else before it was 20/10 but still thanks for reading n will b benfical for others to know what to do if they c shaking screen :) next time