Today, literally Blinkenlights!
When recapping the PM6670, it occured to me I'd like the trigger indicator only the "higher end" PM6671 and PM6672 of that particular series have. The PCB's are all the same and I did have to take off the front panel to get to some 'lytics hiding behind it anway, so I drilled two holes and installed the LED's. Getting the knobs off to remove the panel is a chore, and worst case the LED's would have stayed dark forever. The additional circuitry needed is described in the service manual and on an option board anway. Today the PCB was milled and populated - but after putting it in, it did nothing
![Scared :scared:](https://www.eevblog.com/forum/Smileys/default/scared.gif.pagespeed.ce.oZptHNcbsD.gif)
On the picture you can see Pin 16 of the IC where the copper is not cleared around it, the IC ground pin. While doing the layout I planned to solder that leg to the top ground plane to also have a necessary ground connection below, saving a soldered wire via and making a more compact layout. But when soldering in the IC just now, somehow
not soldering that lead on top, to have less hassle removing it again in case it would not work, seemed more appropriate
![Roll Eyes ::)](https://www.eevblog.com/forum/Smileys/default/rolleyes.gif.pagespeed.ce.XcUK202Yqt.gif)
Thankfully it all came back to me after short confused probing around and staring at the PCB. It works now, but only up to ~15MHz. I think I might need a faster PNP transistor on there than that BC807 at hand - original used 2N5771
![](https://i.imgur.com/KAOVxkd.jpg)
![](https://i.imgur.com/YWcFI9K.jpg)
![](https://i.imgur.com/CGGGthN.jpg)
![](https://i.imgur.com/6TLjqyr.jpg)