> -Original Message-
> From: cctalk On Behalf Of Tony Duell via
> cctalk
> Sent: 31 March 2022 04:26
> To: Noel Chiappa ; General Discussion: On-Topic
> and Off-Topic Posts
> Subject: Re: PDP 11/24 - A Step Backwards
>
> On Thu, Mar 31, 2022 at 3:52 AM Noel Chiappa via cctalk
> wrote
On Thu, Mar 31, 2022 at 3:52 AM Noel Chiappa via cctalk
wrote:
> If the machine then runs, it's up to you as to whether you get the P/S
> repaired so that ACLO work properly - your call. (I wonder how the -15V got
> to ACLO - I suspect a solder bridge from the prior repair - but knowing the
> ans
> From: Rob Jarratt
> I found these two signals and ACLO is low (-15V)
'Good news, bad news'...
Bad is that something is seriously wrong there; 'allowed' values are 0v
(asserted) and +3V (un-asserted). I'm worried that the -15V will have taken
out some of the semiconductors that are 'lis
I found these two signals and ACLO is low (-15V) so I guess this must be the
problem and whatever blew inside the PSU is probably the reason this signal is
low. DCLO is high and the DC ON light is illuminated, but the CPU doesn't do
anything presumably because ACLO is asserted.
Regards
Rob
>
You were right, it is switching noise. As you said, I was zoomed in too far, I
hadn't paid proper attention! The actual ripple is about 50mV peak to peak.
https://rjarratt.files.wordpress.com/2022/03/pin-1-5v-averaged-ripple.jpg
Regards
Rob
> -Original Message-
> From: cctalk On Behal
