I personaly did not have to make that move but would recommend to downgrade to 1.50 and then back up to 2.53.
That should be possible via the Recovery function.
(simply put the 1.50 eboot as /PSP/GAME/RECOVERY/EBOOT.PBP)
that should bring you down to 1.50 then you can go back up
I opened my psp twice and had some problems with the flatband cable betwen motherboard and display. but you seem to know your ways aroud the hardware better then me (i wold not dare to try to install a modchip on my own)