My 450D doesn't power up - is there a schematic?

Hi Forum,

Recently I bought 450D cheap on ebay ("for parts, not working")

It was hit hard by previous owner (probably fell on concrete), such that power board was bent and probably some components were cracked as well. I replaced the board with another one (probably working, I had to repair the FFC connector latch, it was broken), but when putting things together, I reversed FFC cable (!!).

Camera was beeping every couple of seconds, and there was no other activity.

After connecting the FFC correctly, now there is no beeping but the camera does not power up,

Does anyone have schematic diagram of this camera, or at least a list of measured voltages/waveforms that would help me diagnose and/or locate the problem on the component level? I don't have other spare working boards to try fix this by replacing boards.

Thank you in advance!

Bojan