MicroVAX II Console Garbling Characters

[Rob Jarratt]

> -----Original Message-----
> From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Ethan
> Dicks
> Sent: 25 August 2016 18:12
> To: rob at jarratt.me.uk; General Discussion: On-Topic and Off-Topic Posts
> <cctalk at classiccmp.org>
> Subject: Re: MicroVAX II Console Garbling Characters
> 
> On Thu, Aug 25, 2016 at 1:05 PM, Rob Jarratt <robert.jarratt at ntlworld.com>
> wrote:
> > Just a bit more info on this.
> >
> > I tried cleaning up the corrosion, and that briefly seemed to make a
> > difference, but then I realised the problem persisted. I looked again
> > and realised that the corrosion around the DE-9 pins was a bit bad.
> > Initially I thought to solder some jumper wires around pins 2 and 3,
> > but when the solder would not melt very easily, I found that it kind
> > of flaked off under a bit of heat and physical pressure. This made me
> > think that although I was getting continuity with my DMM, the joint
> > was not that good. So I desoldered the whole DE-9 connector, cleaned
> > the board with PCB cleaner and then resoldered it back.
> >
> > This seems to have fixed it.
> 
> My own cab kit was also exhibiting gray solder that did not flow, so without
> even testing it, I presumed it was faulty and I removed the
> DE-9 and cleaned the PCB.  That's as far as I've gotten this week.  I still plan to
> test the resistance of the traces because, sometimes, those are consumed or
> heavily damaged (I've been reading a lot of Amiga Varta repair threads lately
> - that's another platform I'm cleaning damage on).  The question I have for
> the MicroVAX is if I trust the integrity of the DE-9 itself.  I can solder in a fresh
> replacement, but I _think_ the old one is probably still good.
> 

Unfortunately I spoke too soon. When I tested it again a bit more extensively, it suddenly stopped working. I am going to have to solder in some wires to pins 2 and 3 and see if that helps.

Regards

Rob