The 48V fuse blew on my VPR PSU after I powered it up the first time with modules in the rack. It tested fine prior to that. After replacing the fuse, I haven't had it blow again. Any idea what might have caused this? Hopefully it won't happen again, but I'd like to know what to watch out for.
[BUILD] CAPI Dual VPR & 51x Floor Box PSU~Official Support Thread
- Thread starter jsteiger
- Start date
Help Support GroupDIY Audio Forum:
Guys, i need your help. Using the smaller rev2 board for the gdiy psu in a custom case and Volkers power transformer.
I have everything soldered now and as i turn on the power button the trafo makes a loud humming sound. So i turn it off after 2 seconds to not harm anything. I soldered the white and yellow primary cables together for series connection and all secondaries are connected to the pcb. What did i miss here?
Thanks
weiss
I have everything soldered now and as i turn on the power button the trafo makes a loud humming sound. So i turn it off after 2 seconds to not harm anything. I soldered the white and yellow primary cables together for series connection and all secondaries are connected to the pcb. What did i miss here?
Thanks
weiss
kante1603
Well-known member
Hello,weiss said:
I'd start lifting all secondaries to sort out whether it is the transformer or the circuit.
Measure all secondary pairs for dcr first,also for shorts amongst them.A quick check for primaries dcr couldn't hurt too.Mains disconnected of course.
If all is good you can measure the ac voltages of the secondaries.
Be careful at this step because of the mains voltage.
Also make sure you have the right primary wires for series connection used.
Does your build have a voltage selector switch?
Best,
Udo.
kante1603
Well-known member
Sorry to hear that,it's sadly the most expensive part.But glad you got it sorted.weiss said:
Breaking a transformer happens sometimes,not often though.Could be broken lead(s) at the point where they leave/enter the transformer itself from too much mechanical stress,an open or interconnecting/shorting winding internally,or a transport damage.Did it work before or was it your first trial powering it up?
You can do a final quick check and measure both primary windings for dcr.What do you get?
Since you can't measure any secondary voltage it means no induction is happening,so the issue is most likely on the primaries side.
Best,
Udo.
The IEC that is shipped with the Floor Box PSU kit has been changed. The Bulgin part became very hard to get. When I did locate them, the price nearly doubled so we made a change. I have updated the pics and build docs in the first few posts of this thread to reflect what needs to be watched out for. It is very simple. Thanks! 
![Electronics Soldering Iron Kit, [Upgraded] Soldering Iron 110V 90W LCD Digital Portable Soldering Kit 180-480℃(356-896℉), Welding Tool with ON/OFF Switch, Auto-sleep, Thermostatic Design](https://m.media-amazon.com/images/I/41gRDnlyfJS._SL500_.jpg)
brianbrianbrian
New member
- Joined
- Nov 24, 2014
- Messages
- 1
trying to troubleshoot an issue for a friend here:
all components installed correctly and solder joints look clean.
- the -16V terminals read correctly and the LEDs light up
- AC48 secondary reads around 60V
- i'm only getting around 4V on the orange and green secondaries but all others read around 20V
- no output from the 48VDC terminal although i'm getting around 60VDC into the regulator (i'm guessing a shorted/fried regulator?)
- no output from either of the +16VDC terminals although i can read 18.7V into each of the regulators with no output
- the sides of the enclosure (heatsinks) are getting very hot to the touch.
any help?
all components installed correctly and solder joints look clean.
- the -16V terminals read correctly and the LEDs light up
- AC48 secondary reads around 60V
- i'm only getting around 4V on the orange and green secondaries but all others read around 20V
- no output from the 48VDC terminal although i'm getting around 60VDC into the regulator (i'm guessing a shorted/fried regulator?)
- no output from either of the +16VDC terminals although i can read 18.7V into each of the regulators with no output
- the sides of the enclosure (heatsinks) are getting very hot to the touch.
any help?
Try loosening the screws holding the reg's to the heatsink sides. Many guys over-tighten them and they short thru the sil-pads.
sharpeleven
Well-known member
just as a sidenote... I recently found out that the top lid does not make a connection with the rest of the chassis on one Floor Box PSU, meaning that there is no connection established between chassis ground and the slide-in top lid. This applies only to one of two units i have. This even though the unit was assembled the regular way.
Just thought it's worth mentioning as a potential safety hazard.
Wondering whats the best course of action. Reinserting the top lid does not fix the issue. I'm thinking about bending one of the rails slightly at one point to force some kind of contact between the enclosure and the lid.
Just thought it's worth mentioning as a potential safety hazard.
Wondering whats the best course of action. Reinserting the top lid does not fix the issue. I'm thinking about bending one of the rails slightly at one point to force some kind of contact between the enclosure and the lid.
OrganizedKonfusion
Active member
Just wanted to say thanks to everyone on this thread! Especially the people who messed up and came here to trouble shoot and warn others. I learned a lot about what not to do from reading through this. I still had a few hiccups, like cutting an LED too short (I don't think I was totally awake yet) and hooking up my Violet and Gray primary leads up backwards.
I'm a total newb when it comes to building electronics kits. This was essentially my first project so I was pretty surprised that it turned on after I caught my mistake with the primary leads. All my DC voltages were in the ballpark and after some tweaking I got them dialed in.
A few words of encouragement to total beginners like me who want to build this kit: You CAN do it! Make sure you have the necessary tools ahead of time. Practice your soldering skills. Do your homework.
Thanks Classic API and everyone else!
I'm a total newb when it comes to building electronics kits. This was essentially my first project so I was pretty surprised that it turned on after I caught my mistake with the primary leads. All my DC voltages were in the ballpark and after some tweaking I got them dialed in.
A few words of encouragement to total beginners like me who want to build this kit: You CAN do it! Make sure you have the necessary tools ahead of time. Practice your soldering skills. Do your homework.
Thanks Classic API and everyone else!
Hi All,
Just wanted to thank Jeff from Classic API and silent:arts for all their hard work on this project. My VPR PSU was up and running on the first try with absolutely no problems! Great documentation is the reason why. It's a real solid product, obviously something I will not have to worry about in the future. I can show it off with pride and that makes me smile. Nice robust circuit design, too. I am going to use two 5 pin Neutrik connectors on the front panel and add a locking toggle to cut off the 48V phantom power.
regards, Ted
Just wanted to thank Jeff from Classic API and silent:arts for all their hard work on this project. My VPR PSU was up and running on the first try with absolutely no problems! Great documentation is the reason why. It's a real solid product, obviously something I will not have to worry about in the future. I can show it off with pride and that makes me smile. Nice robust circuit design, too. I am going to use two 5 pin Neutrik connectors on the front panel and add a locking toggle to cut off the 48V phantom power.
regards, Ted
Hi everyone,
I've run into a problem with the dual VPR that I need help tracking down. I'm extremely new to this, and tracking down problems is something I'm a complete novice at, so my apologies in advance. This is probably gonna be an "explain it like I'm 5" thing, but I really want to understand how to do this.
So I've powered up the unit, and four of the leds are lit up. The -16V on the right side is not. I've flipped the led around to make sure that wasn't it, but it still didn't light up. I tested the JP1 screw terminals and these were the values I got:
GND = 0
CHA = 0
+48 = +48.97
-16 = -16.48
+16 = +16.45
+V#2 goes between .000 and .002
-V#2 goes between .000 and -.001
+48 = +48.97
GND = 0
CHA = 0
So from Jeff told me, the +V#2 and -V#2 should both be close to 16V. So from the little I know how to do, this is what I've checked for. I took the supply apart, and flipped it over to check all the connections. It looked good but there were a couple of spots on the -V#2 side of the board that I touched up, just to be on the safe side. I also loosened up the screw by the IC regulator into the heatsink side cause I know if it's too tight it can short out. I'm also not getting any current at the out led, but all the others get current.
I also started trying to put the toroid connectors in pairs, one at a time and see which ones lit up which front leds to try to see where the problem was. I put the two red ones in, got one of the front leds to light, and promptly blew the 2.5A fuse in the back. Not sure if I should not test it out that way or not.
Any help here would be greatly appreciated.
I've run into a problem with the dual VPR that I need help tracking down. I'm extremely new to this, and tracking down problems is something I'm a complete novice at, so my apologies in advance. This is probably gonna be an "explain it like I'm 5" thing, but I really want to understand how to do this.
So I've powered up the unit, and four of the leds are lit up. The -16V on the right side is not. I've flipped the led around to make sure that wasn't it, but it still didn't light up. I tested the JP1 screw terminals and these were the values I got:
GND = 0
CHA = 0
+48 = +48.97
-16 = -16.48
+16 = +16.45
+V#2 goes between .000 and .002
-V#2 goes between .000 and -.001
+48 = +48.97
GND = 0
CHA = 0
So from Jeff told me, the +V#2 and -V#2 should both be close to 16V. So from the little I know how to do, this is what I've checked for. I took the supply apart, and flipped it over to check all the connections. It looked good but there were a couple of spots on the -V#2 side of the board that I touched up, just to be on the safe side. I also loosened up the screw by the IC regulator into the heatsink side cause I know if it's too tight it can short out. I'm also not getting any current at the out led, but all the others get current.
I also started trying to put the toroid connectors in pairs, one at a time and see which ones lit up which front leds to try to see where the problem was. I put the two red ones in, got one of the front leds to light, and promptly blew the 2.5A fuse in the back. Not sure if I should not test it out that way or not.
Any help here would be greatly appreciated.
Attachments
One thing is confusing me. You had only one LED not working but are not measuring DCV at 2 of the 5 outputs. That is not possible really. If you do not see any DCV at 2 of the output terminals, then 2 of the LED's should not be lit.
Hmm, odd because the LED's do not jive with the DCV on the output header. Unless the PC pin for the header is not soldered, this is not possible. I am referring to the header pin with no voltage reading but a working LED. I think its +V#2. Let's look at that first an then worry about the -V#2 issue.Angryzen said:
OK! Made some progress. I re-soldered the +V#2 and -V#2 JP pins just to be safe. I then noticed one of the connections on the +V#2 trim wasn't solid, so I soldered that again, just to be safe.
Now, I'm getting +16 on the +V#2 JP, but the -V#2 is still showing no charge. Should I look for a similar thing with the trim? Could it be another bad solder connection?
Now, I'm getting +16 on the +V#2 JP, but the -V#2 is still showing no charge. Should I look for a similar thing with the trim? Could it be another bad solder connection?
I would definitely start with potential bad solder joints. You should also measure DCV at both ends of the fuse for -V#2.
You have -16V at both ends of F2? There is nothing between the left end of F2 and the -V#2 header terminal but the solder joint on the fuse and the solder joint on the terminal. I would reflow the solder on the F2 fuse holder, the end closest to the J1 terminal block.
Also, measure DCV from both ends of R8. That is the series R for the -V#2 LED. You can also check DCV at the small via just behind LED2.
In the attached screenshot, I have highlighted the trace that runs between F2 and the terminal pin. There is nothing in there to go wrong.
Also, measure DCV from both ends of R8. That is the series R for the -V#2 LED. You can also check DCV at the small via just behind LED2.
In the attached screenshot, I have highlighted the trace that runs between F2 and the terminal pin. There is nothing in there to go wrong.
Attachments
Hey Jeff,
Sorry for not responding for a bit, I got sick and ended up in the hospital. Things are getting better now. So I just finally got a chance to look at things. I think I know what the problem is. So when I'm checking the DCV on pins 1 and 2 of F3, 4 and 5 I can see the DCV on both pins 1 and 2. When I check on F2, there is no charge on pin 1 going to the led. I reflowed the solder on both pins just to be sure, but it's still not sending any power. And there is no DCV on R8. So am I right in guessing that pin 1 on F2 is most likely the culprit?
Sorry for not responding for a bit, I got sick and ended up in the hospital. Things are getting better now. So I just finally got a chance to look at things. I think I know what the problem is. So when I'm checking the DCV on pins 1 and 2 of F3, 4 and 5 I can see the DCV on both pins 1 and 2. When I check on F2, there is no charge on pin 1 going to the led. I reflowed the solder on both pins just to be sure, but it's still not sending any power. And there is no DCV on R8. So am I right in guessing that pin 1 on F2 is most likely the culprit?
Similar threads
