@orange:
I think the mask printed on the A3640 pcb has the wrong polarity printed for part of the capacitors and was the reason A3640s used to have a part of its capacitors reversed in the past. Thus the mask doesnt match the polarity of part of the capacitors on your A3640. Anyhow, to know for sure - just measure as already suggested.
(edit):
Your capacitors are atleast turned the same way as on a A3640 I have here which has had its capacitors replaced and polarized correctly.
/Patrik
