Aesthetically pleasing repair - UK Vintage Radio Repair and Restoration Discussion Forum

ScottishColin · 10th Sep 2022, 4:34 pm

As some of you may recall, one of the failures I had on my PET was the loss of Ground connectivity on UD9 pin 12. I've got past this by pushing a wire in pin 12 of UD 6 and UD9 - see attached photo.

I'm pretty sure that even though this works, it isn't the 'right' way and was wondering what you would do in this situation?

Fix the pin12/UD9 problem if possible
Solder a wire under the board from UD9/12 to an earth
Solder a wire on the top of the board from UD9/12 to an earth
Leave well alone
Something else

All opinions gratefully received.

Colin.

G6Tanuki · 10th Sep 2022, 5:34 pm

I would want to do it properly, with an appropriate link on the underside of the PCB.

"Verowire" - available from RS, is insulated wire that is very thin, traditionally dispensed frtom a "wiring pen" that includes a spool. The wire is 'self-fluxing' - no need to strip, the heat of the soldering-iron melts through the insulation.

This is great for making quick-and-dirty but long-term-reliable amendments to PCBs; there is even a special quick-set glue and 'combs' avasilable to keep the newly-added wire-links neatly in place.

https://www.instructables.com/PCB-Pr...With-Verowire/

Mark1960 · 10th Sep 2022, 6:25 pm

It looks like the 0v connection to pin 12 is on the top side of the pcb. As you used a turned pin socket you might be able to remove a bit of solder resist from the 0v track and solder pin 12 of the socket directly to the 0v track.

Phil__G · 10th Sep 2022, 7:01 pm

Whichever way you choose, write it down on a slip of paper that lives permanently under the PCB!

SiriusHardware · 11th Sep 2022, 8:10 am

Quote:

under the PCB!

And that's also where I would do the repair, on the underside of the PCB, by linking UD9 socket pin 12 to UD8 socket pin 12 with a piece of thin insulated wire like 'kynar' or 'wire wrap' wire. If I were Colin.

If it was me, I would have to know where the problem really was and I would start by using a hot wire or hot scalpel blade to slice the frame of the turned-pin socket up into little bits so that each socket pin stood alone and could be individually desoldered and removed, leaving only the pads to be cleared, examined and repaired as necessary. Then, I would fit a new conventional socket because whatever their drawbacks compared to turned pin sockets, they are much easier to remove and replace.

10th Sep 2022, 4:34 pm	#1
ScottishColin Octode Join Date: May 2012 Location: Perth, Scotland Posts: 1,803	Aesthetically pleasing repair As some of you may recall, one of the failures I had on my PET was the loss of Ground connectivity on UD9 pin 12. I've got past this by pushing a wire in pin 12 of UD 6 and UD9 - see attached photo. I'm pretty sure that even though this works, it isn't the 'right' way and was wondering what you would do in this situation? Fix the pin12/UD9 problem if possible Solder a wire under the board from UD9/12 to an earth Solder a wire on the top of the board from UD9/12 to an earth Leave well alone Something else All opinions gratefully received. Colin. Attached Thumbnails

10th Sep 2022, 5:34 pm	#2
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 13,996	Re: Aesthetically pleasing repair I would want to do it properly, with an appropriate link on the underside of the PCB. "Verowire" - available from RS, is insulated wire that is very thin, traditionally dispensed frtom a "wiring pen" that includes a spool. The wire is 'self-fluxing' - no need to strip, the heat of the soldering-iron melts through the insulation. This is great for making quick-and-dirty but long-term-reliable amendments to PCBs; there is even a special quick-set glue and 'combs' avasilable to keep the newly-added wire-links neatly in place. https://www.instructables.com/PCB-Pr...With-Verowire/ __________________ I'm the Operator of my Pocket Calculator. -Kraftwerk.

10th Sep 2022, 6:25 pm	#3
Mark1960 Octode Join Date: Mar 2020 Location: Kitchener, Ontario, Canada Posts: 1,294	Re: Aesthetically pleasing repair It looks like the 0v connection to pin 12 is on the top side of the pcb. As you used a turned pin socket you might be able to remove a bit of solder resist from the 0v track and solder pin 12 of the socket directly to the 0v track.

10th Sep 2022, 7:01 pm	#4
Phil__G Octode Join Date: Mar 2011 Location: North Yorkshire, UK. Posts: 1,115	Re: Aesthetically pleasing repair Whichever way you choose, write it down on a slip of paper that lives permanently under the PCB!