Newly assemble pl14 rev G bias trimmers do not work correctly
- Thread starter CrazyIvan
- Start date
As usual, I'm late to the party. Saturday night when this thread started the wife did a stage dive, 12 steps down and landed by the front door. Fortunately no broken bones. 10 stitches to sew up the gash in her knee. Sunday, traveled to Houston office to teach a class this week. NOt much time for anything else.
To move forward and answer a couple questions:
Who built the board? The important thing is who doesn't, me. "Tami" builds the boards. She runs the PCB dept at my day job. Has all of the certifications including ISO-9000 and is part of the team for components qualified for use in safety related equipment at nuclear power plants. And she's human. She's built built hundreds of boards for me and 1000's at the day job. Thus far on my boards she put 1 chip in backwards and had a bridged solder joint . I can live with that.
If anyone ever wondered why there is a drop of finger nail polish on a DCP board, it's my QC stamp. Every board gets inspected, and then tested in a working amplifier to verify proper operation on both inputs. On the back of the board I stamp the date. When inspecting the boards I usually focus on solder bridges, especially around the binding posts. I missed this one.
Next question: Is wattsabundant easy to deal with? I do this for beer money (1/6 barrels). It's not intended to pay the rent. I don't have a P&L statement. In instances like this I ask the question, what's the right thing to do? Answer: Replace the board. I consulted Spencer on that last night over beers.
I wish I had known about the issue before the attempted surgery on the board, and the surgery on my wife's knee, and the problem could have been avoided.
If a cap has to get installed backwards on the DCP, C7 is the one to do. That's the timing cap on the detector. It rarely sees more than a few millivolts and had it been left alone would have been fine. Electrolytics can withstand a certain percentage of reverse voltage. I've been wanting to address that here and intend to do so soon. I have a great document on electrolytics (29 pages I think) that I include in the document package for my training classes. I also have an OE (operating experience in nuke-speak) on a cap installed backwards.
Todd: I'll send another board and ask you return the old one. I keep an emergency stock at my Houston office. It will go out in a day or two. In the mean time I would like to see a photo of the damage.
To move forward and answer a couple questions:
Who built the board? The important thing is who doesn't, me. "Tami" builds the boards. She runs the PCB dept at my day job. Has all of the certifications including ISO-9000 and is part of the team for components qualified for use in safety related equipment at nuclear power plants. And she's human. She's built built hundreds of boards for me and 1000's at the day job. Thus far on my boards she put 1 chip in backwards and had a bridged solder joint . I can live with that.
If anyone ever wondered why there is a drop of finger nail polish on a DCP board, it's my QC stamp. Every board gets inspected, and then tested in a working amplifier to verify proper operation on both inputs. On the back of the board I stamp the date. When inspecting the boards I usually focus on solder bridges, especially around the binding posts. I missed this one.
Next question: Is wattsabundant easy to deal with? I do this for beer money (1/6 barrels). It's not intended to pay the rent. I don't have a P&L statement. In instances like this I ask the question, what's the right thing to do? Answer: Replace the board. I consulted Spencer on that last night over beers.
I wish I had known about the issue before the attempted surgery on the board, and the surgery on my wife's knee, and the problem could have been avoided.
If a cap has to get installed backwards on the DCP, C7 is the one to do. That's the timing cap on the detector. It rarely sees more than a few millivolts and had it been left alone would have been fine. Electrolytics can withstand a certain percentage of reverse voltage. I've been wanting to address that here and intend to do so soon. I have a great document on electrolytics (29 pages I think) that I include in the document package for my training classes. I also have an OE (operating experience in nuke-speak) on a cap installed backwards.
Todd: I'll send another board and ask you return the old one. I keep an emergency stock at my Houston office. It will go out in a day or two. In the mean time I would like to see a photo of the damage.
![IMG_4157[1].JPG](/data/attachments/63/63448-1e8648d3eace7f5db0aa2ba0a7820198.jpg)