[BUILD] CAPI Dual VPR & 51x Floor Box PSU~Official Support Thread

I checked, double checked, and triple checked all of my solder joints in the 48v section. I've ordered another rectifier and a regulator. Going to swap them out...

It's unlikely that they are bad from the get go but anything is possible though. If you are gonna change them, just do one thing at a time to see exactly what the issue is.

BTW, did you check ACV at the entry of BR1? It should be the same as at the toroid terminals but best to be sure.

I haven't checked, but I will tonight.

I'm going to start with the rectifier as it seems too much of a coincidence that my voltage is essentially exactly half of what it should be... Although, I'm not crazy about taking the case apart, putting it all back together, and then potentially having to do it all over again if it's not the rectifier... But I figure it's the least I can do for you.

You only need to remove the back & bottom. Leave the PCB, front and sides together. I would still be surprised if the rec is bad.

SO, I just probed both legs of C7 and C6 (not the ones connected to ground and I'm seeing 19.3V AC... why would that be?

.....and then as I was pulling my probe out (slowly) I shorted one end of F2 blowing that fuse and causing something else to POP somewhere in the -V2 circuit... fun.

Hi peeps!

So I've finally got around to building my 51x PSU, and I (think) it's mostly gone OK! (phew!)

I'm now at the pre-toroid wiring stage, and there's a discrepancy between my IEC socket and the other European ones on this thread...mine doesn't have a pin for the main earth, while the other Europeans in this thread seem to have one. See attached photo.

Surely this is bad? (FYI, I got my kit from Volker, so I've got no reason to think it's wrong unless it's a component error!)

Isn't this (non-existent) pin supposed to be connected to the star ground?

Thanks for the help guys!

Kaz

Hello Kaz,

I've got mine from Volker too,but your's looks wrong.
Safety earth is imperative here!
You should contact him,I'm sure he will help you.

Best regards,

Udo.

Edit:Looks like the earth pin is missing,seems to be a component error.

DON'T USE IT WITH(OUT) THIS MISSING PIN !!!

[silent:arts] said:

DON'T USE IT WITH(OUT) THIS MISSING PIN !!!

Click to expand...

Don't worry I wasn't going to!

I'm not experienced enough to know about the voodoo & tricks that you experienced guys use in your circuits, which is why I checked...but even with my rather limited knowledge, it seemed like a good way to electrocute myself... 

For others reading this...if in doubt ask!

Volker, I'll email you about this off thread so as not to pollute the discussion...

nah, this is no voodoo trick, it is just basic safety!
replied to your mail, will post you a replacement today.

Thanks Volker.

Oh, and thanks for confirming my suspicions too Udo! You guys are so helpful.

Right, so in a bid to eliminate uncertainty for other EU builders and to keep things rolling in general, here's a pic of my build as it stands. Obviously some things are missing as I'm not finished yet, but there are a couple of things to note if you're are building using Jeff's guide, but using the EU kit from Volker.

- The EU toroid comes with a glued on insulator underneath it, so there's no separate cloth insulator supplied like in Jeff's guide.
- The EU toroid only needs to be secured with one of the combo nut-washer things.

Also, when I strip wires I tend to use side cutters as my wire strippers are a bit inaccurate for that and most of the time that's fine. However, once you cut the toroid wires to the right length, things get a bit more critical as you don't want to end up having to cut off much more if you accidentally snag one of the strands of wire, so I stripped my secondary wires using a spare tip on my soldering iron to burn the cable insulation off instead. I guess it's probably a little more toxic, so make sure your room is well ventilated, but it's nice not to have to worry about removing some strands accidentally (just to be clear, you only need to burn a single ring around the wire to make the cut and then pull the disconnected insulation off like normal).

And finally to admit to a minor build error, and assure others that it's ok to stay calm and fix things:

A few nights ago when it was late and I was probably a bit tired and on auto-pilot, I accidentally soldered the molex connectors for the secondaries backwards, so that the holes for the wires were facing in towards the centre of the pcb! Hah! If that happens, don't panic. Each connector (pair of contacts) can be removed individually which makes it a bit easier.

A bit of patience, a bit of heat, a light touch with some pliers to ease them away from the board far enough to get some tweezers inbetween the board and the bottom of the connector so that they can be used as a lever while applying heat to the pins in multiple passes moving each pin around a millimetre at a time gets the job done. I think the entire housing for a molex can actually be pulled off first so that each pin can be done one at a time if you want to make it even easier, but I found my initial approach fairly straightforward and the connectors were left in perfect condition!

Anyway, there you go, hope that helps the other newbie builders like me!

;-)

Hi everyone! First post on Group Diy woohoo!  ;D

I received the 51x rack + PSU last week and started the build yesterday. So far everything is flawless. (hope the attached pic will post correctly)

I am at the step where to put the regulators in but it does not mention anything about putting heatsink compound on the mica... Have you guys put any? The mica are good enough on their own to transfer the heat?

Thank you!

Max002 said:

Hi everyone! First post on Group Diy woohoo!  ;D

I received the 51x rack + PSU last week and started the build yesterday. So far everything is flawless. (hope the attached pic will post correctly)

I am at the step where to put the regulators in but it does not mention anything about putting heatsink compound on the mica... Have you guys put any? The mica are good enough on their own to transfer the heat?

Thank you!

Click to expand...

Hi Max002!

I'm new to this myself, so probably not the best to comment, but I didn't put any heatsink compound on anything and I can't say that I've seen any mention of it in the guide or anywhere else if that helps!

Kaz

Nothing else but the pads under the regulators needed.

Happy building and welcome,

Udo.

My 48V is fixed... my -16 V#2 is still down though.

When I shorted it, I definitely popped the regulator, so I replaced:
-the LM350 regulator,
-the 1k trimmer,
-C8 .1uf Wima
-C9 big boy.

Still doesnt work. My next thought is to replace the diodes and resistors R3 and R4 as that was the area that had the smoke. Is there something else that is likely to have popped?

Thank you,
Greg

and I'm 100% in business now!!! 

What was the issue Greg? Maybe it'll help someone in the future.

I'm not exactly sure on the 48V... I swapped out the regulator and redid the insulating... Also, I reheated every solder joint in the path.

When I popped the F2 fuse and lost my -V2 rail, I replaced the following things in the following order:

First round: LM350 regulator (definitely blown), 1k trim (probably blown), C8 (def blown), C9 (wasn't sure)... Didnt work.
Second round: diodes and R3+R4... I think this was probably unnecessary... Didn't work
Third round: electrolytics C11 and C12. WORKED

Now, to test the 22 slots I just finished building!  ;D ;D

Edit... all 22 slots test perfect! While I was at it, I fixed an Old School Audio power supply (I know.... cringe)... Simple swap out of the LM723 so I am in +/-16V heaven...

AND I've got the electrical inspector coming this week to review the 6, 20A circuits that we brought out into the old barn that I've been converting to a studio for the past year+. I'm VERY close. Needless to say, I'm very excited!

Just wanted to come back here and let everyone know that Volker was a true gent and sorted me out with a new IEC socket which arrived over the weekend. I've just got around to installing it and my first power up and everything seems to be working great!

I trimmed the voltages to 48.5, -24.7, 24.7, -16.7, 16.7 as mentioned in Jeff's guide. Took a while as I didn't have a plastic tool to use to do the trimming, so I had to power down between tweaks and wait for the capacitors to discharge, but even using that approach, only took about four iterations total to get right, so not particularly laborious! (keep an eye on those 24v leds, as the associated capacitors take a long time to discharge). Just need to get around to hooking up the output cabling now, but that's a job for another day.

The fact that a simple mind like mine was able to get it going so easily, is a testament to the awesome detail on this thread, so thanks guys!

Thanks Volker for getting that replacement part to me so quickly, and with extra gummi bears too!

Kaz

can anyone tell me why my -v#2 section smokes and the led flickers when i power on my psu for initial testing and the led4 +16 wont light up at all? i checked all the solder joints. Has anyone experienced this problem or know a viable solution?