RE: Testing a H744 Regulator on The Bench

2021-12-31 Thread Rob Jarratt via cctalk
Subject: Re: Testing a H744 Regulator on The Bench Den tors 30 dec. 2021 kl 19:08 skrev Rob Jarratt via cctalk mailto:cctalk@classiccmp.org> >: Hello All, Following a discussion on resurrecting a PDP 11/45 I have started looking at the regulator bricks in the PSU. I have s

Re: Testing a H744 Regulator on The Bench

2021-12-30 Thread Vincent Slyngstad via cctalk
On 12/30/2021 10:08 AM, Rob Jarratt via cctalk wrote: Also, the indicator light does not work (as expected). I have seen the suggestion to replace it with a CM7381. It looks like these can be sourced with relative ease,

Re: Testing a H744 Regulator on The Bench

2021-12-30 Thread Jonathan Chapman via cctalk
Sounds like you're testing things basically the way I was: http://www.glitchwrks.com/2019/06/05/pdp1110-psu-repair I used a large Stancor 24 VAC transformer to supply power to the modules, since they usually see 20-30 VAC from the big transformer in the chassis. For dummy loads, I like

Re: Testing a H744 Regulator on The Bench

2021-12-30 Thread Mattis Lind via cctalk
Den tors 30 dec. 2021 kl 19:08 skrev Rob Jarratt via cctalk < cctalk@classiccmp.org>: > Hello All, > > > > Following a discussion on resurrecting a PDP 11/45 I have started looking > at > the regulator bricks in the PSU. I have started with a H744. I reformed the > three big capacitors, although

Testing a H744 Regulator on The Bench

2021-12-30 Thread Rob Jarratt via cctalk
Hello All, Following a discussion on resurrecting a PDP 11/45 I have started looking at the regulator bricks in the PSU. I have started with a H744. I reformed the three big capacitors, although they seemed to be fine as they charged up from my DC bench PSU and then had zero leakage so I