> ... At startup, sometimes about 90 % of all leds are on,...
> but is not possible to change any parameter. Sometimes,
> after a couple of secs goes ok.
> I'm suspecting that the DC OK signal sometimes is not up...
> I'm gettingIf this is actually the output of the 5V digital line that you're reporting,
> a maximum DIGITAL DC +4.2 (maximazing the trimmer, 4.01 at minimum
> position). I have the second type board (so no trimmer for the DIG OK
> signal)
then that would seem to be the source of the problem (i.e., 4.2v is .6 or .7
volts too low for good operation - and per the docs, you should be up at 5.0v).
The solid-on LED indication would indeed likely be due to the DC OK signal
never getting up there (since the power supply is struggling to get to a point
where the 5V is "ok."
If the voltage is really that low too - then other system operation would also
be questionable.
> Do you think is the LM350k or is the power coming in that is too low ?I wouldn't immediately expect the electrolytics, but I would certainly look at
> and what would be the correct incoming voltage from the transformer?
> Can be the low voltage caused by old lytics caps ?
the input voltage to the LM350 to see what sort of levels you are seeing. If
you can, it would probably be good to look at this with a 'scope.
While the circuitry between the old and new PSUs are different, I would still
expect to see the same order of magnitude of voltage going into the voltage
regulator - so that'd be about 13V coming in, with a ripple frequency of 120Hz.