K810i EROM repair?

Hi guys..my k810 does'nt start n nly a red light blinks in the ir port..also battery is proper..so i think its a erom prob..wt do u guys thnk? And here are my questions
1.how many logs should i buy to repair erom
2.can i also downgrade from cid 53 to 52 while repairing or should i buy extra logs? Thanks

Read here : Top Sony - Buy Ultimate Unlocker LOGs

Ya but which one should i buy? The supreme log or the other one?

you can buy the 0.40 log but remember to select downgrade CID if you need to downgrade before hitting the action button