Jon wrote:

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I did try doubling up the 4700uF with another which yes I checked the
capacitance of first.

Also what are R602 and D605 for ?


** They de-couple the two electros, so the voltage on C604 does not follow the ripple on C603, allowing it to hold a higher average DC value.

Using your 1.4A load figure for the PSU with a 4700uF smoothing cap - the p-p ripple voltage works out at 1.9 volts.

I = C dv/dt ( where dt = 6.5mS )



.... Phil