(adsbygoogle = window.adsbygoogle || []).push({}); i get a error when i install a 4.xx cfw from my 3.55 ps3 :S

try to QA Flag your console first, and then try to use 4.21 Rebug (REX Best CFW ... my opinion)
and if that doesnt work, try to get your console back to 3.55 OFW and maybe at least the firmware is indeed damaged

console qa flagged,
i cant install any 4.xx cfw.... :S

i have had this problem before after i downgraded with REBUG 999. all i did was format my HDD(Quick) and then start it threw recovery mode and then it finally worked.

try what the guy above me said, i never had problems with installing 4.xx CFW,
but i directly updated my 2.76 Console (XD) to 4.21 REX when my old 3.55 broke

This is what you need to do. Download the DowngraderPUP, after you have downgraded install the QA Flag from Rebug. After that,try to install 3.55 V3.7A. And Finally CFW 4.21 or 4.30. If for any reason you can't install 3.55 V3.7A, you must go back to OFW 3.55 and install the other ones: