PinOut of DEC F11 Chips in a Professional 350

[Rob Jarratt]

> -----Original Message-----
> From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Patrick
> Finnegan via cctalk
> Sent: 27 October 2018 13:48
> To: General Discussion: On-Topic and Off-Topic Posts
> <cctalk at classiccmp.org>
> Subject: Re: PinOut of DEC F11 Chips in a Professional 350
> 
> On Sat, Oct 27, 2018, 04:06 Rob Jarratt via cctalk <cctalk at classiccmp.org>
> wrote:
> 
> >
> > I have been tracing the source of the RESET, because as I have said it
> > is oscillating, and it seems to go through a *lot* of logic, and I
> > haven't fully traced the source of the oscillation yet.
> >
> 
> Have you checked the PSU output? My first guess would be bad caps in the
> power supply.
> 


I should have said that I have already checked, the ripple is about 100mv peak to peak, which I assume is OK. The green DC OK LED is illuminating too, so I think the PSU is fine.

Regards

Rob