Sooooo…I accidentally put the box header on backwards on my Performance Filter. It was the first module I built and didn’t realize I had flipped it. (The little outline photos on the other PCB’s are very helpful to avoid this…LOL) Unfortunately, I quickly learned the lesson of what happens when the power is flipped. I burned out the two 10R resistors and had to replace those. The box header also needed to be replaced. However, when I removed it two of the barrels came out entirely of their holes and now I don’t have anything to solder the pins to.
I saw some YouTube videos and sites say I needed to place new copper eyelets in the holes and then I should be fine, yes? Does anyone know what size eyelets I need for Sam’s PCB’s? What is the thickness of his PCB’s so I also know the length to get.
As always…thanks for the information. I really appreciate everyone on these boards who has helped me.
Post a pic! Ive done that a few times, i just end up resoldering the thing. I have had some success some times in pulling the black box part off of the pins, then reseating it. I say this, but have never been able to do that without fully resoldering it since to loosen the box i had to heat it up.
It’s a bit hard to see, but the entire barrel came out of two of the holes. I think it is because I initially used a lead free solder when I did this board, which required a temp of 425 to melt. It was too hot for the board and I think once I had to remove this component it was too damaging. I have since switched to a lead solder. I had talked to Christian about fixing a trace not long ago and he suggested using a wire for that, but with the barrel I assumed replacing with an electrical eyelet would work well. I have everything to punch and secure the eyelet, but I don’t know what size to order.
The photos show the front and the back before I cleaned any of it up.
I think you can save this by just soldering in the new connector where you still have plating, then connecting the left and right pins in each pair with a solder bridge or a short piece of wire. Then use a multimeter to check that you have connections for +12V and −12V (the six GND pins are well connected), and if necessary scratch off the solder mask from the corresponding track, and solder in a wire from the right pin to the track.
So I put the new component in and soldered a bridge between the left and right pins. I checked with the multimeter and I am receiving -12V, but I am not receiving +12V. Also, now when I plug in the module to my frequency central powerbus the +12V LED on the powerbus turns off. If I unplug the module then it turns back on. I checked all of the pins on the powerbus and they are outputting correct voltage. All of the other modules (I think) work. They at least can receive power.
(Side Note: I don’t know if they actually work as I do not have a clock generator or midi/CV module yet. However, I at least know that the VCO’s were able to get the software uploaded and tested correctly.)
Can you further explain what you mean by scratching off the solder mask and soldering in a wire to the right pin? I am assuming this is the next step I need to take, but I am not following what I need to do here.
As a point of reference the pins at the top are the +12V. Interestingly, the pins at the bottom for the -12V were the two holes that the barrels came out of. However, soldering a bridge between these two seemed to work.
I looked at it again and I think what you’re seeing in the photo is just the reflection of the flux residue. Here are a couple of better photos. Let me know if you see anything I’m missing.
Yeah, seems you have both a short and a missing connection. Time to bring out the multimeter and check what’s connected to what! – check that you have continuity from the +12 power pins to e.g. the VCC+ pin on the opamps (pin 4 on the TL074), and likewise from −12 to VCC− (pin 11). Then make sure that there’s no direct continuity between the 12V pins themselves, and no continuity between them and the GND pins.
In this thread: Why leaded solder is advisable. :<
I run at 700°f / 371°c, and only scorch if im not careful. Also Leaded solder is way easier, so i don’t have to fuss with it nearly as much. It really is night and day for me.
Back like 8 years ago when i first started this (gave up cause i was poor AF) i used lead free and thought i was terrible at soldering. I’m no expert, but hell as soon as i swapped it was like i was a savant by comparison.
So I checked everything again. I have continuity between the +12V and pin 4 on the TL074. I do not have continuity between -12V and pin 11 on the TL074. The two -12V holes are the ones that I was initially concerned about as the barrels came out of both. I’m afraid to ask…is this fixable?
I don’t have time to look at the PCB right now, so will only give you handwavy instructions, but the easiest fix is to solder a wire from the −12 V pins on the power connector to another −12 V part of the circuit, e.g. by scratching off the solder mask on a nearby −12 V track to get at the copper, or find a nearby −12 V IC/component pin.
EDIT: @sebastian located a perfect spot, see below.
Thank you for the visual! I thought that was where it could go but I was nervous that I might break something else on the board if I put a wire there without being 100% sure about it being right. I’ll try that and let you guys know what happens.
Okay, the wire is now connected. I now have continuity between the -12V and the TL074. However, when I plug in the module the led for the +12V on my microbus still turns off. I checked the pins on the other box headers on my microbus with this module plugged and it shows that my voltage on the +12V pins drops to about .27
I do receive -12V on all of the header pins.
I unplugged this module and plugged in one that I know works and my LED for the +12V works perfectly fine and I am receiving the correct +/-12V on all of the box headers.
Does any of this make sense? Not sure what to do here.
Maybe I’m overlooking it but I don’t see above if you’ve said you’ve checked to make sure there’s no continuity between +12V and ground. So do check that if you haven’t. If there isn’t a short to ground it does look like there at least is a low resistance path to ground, so look for solder bridges on or near the +12V bus.
If I understand correctly this module uses this circuit diagram https://www.schmitzbits.de/ms20.html on which I don’t see the +12V (actually +15V on that diagram) connected to anything except implicitly the power pins on the ICs (oh, and the top of one pot). So you could check to make sure there’s no continuity and no very small resistance between the +12V pins and anything other than the IC power pins.
So I do NOT want continuity when I use my multimeter and touch one point to the +12V and the other to any of the grounds on the box header? Is that what I am hearing you say?
(btw…I realize I sound like a dumbass when it comes to DIY circuitry. I literally came into this knowing absolutely nothing about any of this, which is obvious, or even knowing anything about eurorack / CV systems. I’ve been writing music behind a computer with software for WAAAAAY too many years.)
I really don’t know what I’d have done without you guys all helping me along the way. I’m sooooo appreciative! So thank you a million times over.
I burned out the two 10R resistors and had to replace those. The box header also needed to be replaced. However, when I removed it two of the barrels came out entirely of their holes and now I don’t have anything to solder the pins to.
