> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Jon Elson
> Sent: 05 December 2015 18:03
> To: gene...@classiccmp.org; discuss...@classiccmp.org:On-Topic and Off-
> Topic Posts
> Subject: Re: Memory Voltage on MicroVAX II
>
>
On 12/05/2015 09:51 AM, Robert Jarratt wrote:
I finally fixed my H7864 PSU so I can now run my rtVAX 1000. However, I
think the machine is damaging memory boards. I checked the ripple and 5V
looks OK, but 12V looks suspicious. Is the 12V supply used by the memory?
I don't have my print set
On 12/05/2015 12:29 PM, Robert Jarratt wrote:
-Original Message-
From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Jon Elson
Sent: 05 December 2015 18:03
To: gene...@classiccmp.org; discuss...@classiccmp.org:On-Topic and Off-
Topic Posts
Subject: Re: Memory Voltage
>
>
> There seems to be a spike on the 12V supply, surely that isn't good, even if
> it doesn't affect the memory?
Often a spike on a particular output of an SMPSU is caused by a high ESR
capacitor
on that output. It's worth checking them.
FWIW, old DRAMs, up to about 16Kbit size, often used
> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Jon Elson
> Sent: 05 December 2015 19:19
> To: gene...@classiccmp.org; discuss...@classiccmp.org:On-Topic and Off-
> Topic Posts
> Subject: Re: Memory Voltage on MicroVAX II
>
>
On 12/05/2015 01:49 PM, Robert Jarratt wrote:
As the 5V seems fine, the ripple seemed to be about 20mV
(although I am going to check again), I do wonder what
could be causing the memory modules to appear to be
failing. I am hoping that re-seating will cure it. Regards
Rob
I ran a uVAX-II for
> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Jon Elson
> Sent: 05 December 2015 23:40
> To: gene...@classiccmp.org; discuss...@classiccmp.org:On-Topic and Off-
> Topic Posts
> Subject: Re: Memory Voltage on MicroVAX II
>
> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Robert
> Jarratt
> Sent: 05 December 2015 19:49
> To: 'General Discussion: On-Topic and Off-Topic Posts';
> gene...@classiccmp.org
> Subject: RE: Memory Voltage on MicroVAX II
&g
