Rowland,
Thank you !
Yes, I did have it already, but still thanks heaps.
Actually, I should have posted the direct link I found by googling earlier...
http://thydzik.com/downloads/canon-s...0d-digital.pdf
However, this service manual is not designed for circuit-level repair, components are very hard to cross-identify and part numbers are Canon internal with no reference to source...
So I will have to try to figure out the apropriate fuse value by replacing it with jumper and then measuring current (DC and peak).
BTW, I must be getting silly recently.. last night I obtained 450D... also with a problem (doesn't read memory card).
So, once I am finished with 400D, I will start work on 450D. One of them will surely become mono.