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

[Toure14]

Also to be more specific...

-16V (LM350T) reg is grounded to same heat sink its screwed to
+48v (TL783C) reg is grounded to same heat sink it is screwed to

The other Regs are open or high resistance to the same heat sink they are screwed to

 

[Toure14]

Front of PSU

 

[Toure14]

Rear of PSU

 

[Toure14]

Top Left of PSU

 

[Toure14]

Bottom Left of PSU

 

[Toure14]

Top right of PSU

 

[Toure14]

Bottom right of PSU

 

[Toure14]

Top left of Soldering

 

[Toure14]

Bottom left of Soldering

 

[Toure14]

Top right of soldering

 

[Toure14]

And finally....Bottom right of soldering

 

[Toure14]

I hope the pics are good enough to help me figure out the problem with my PSU. As I said before my fuses are good, none are blown.

I believe all my solder joints are good as well. nothing bridged or cold. Well what is a cold solder joint? I don't believe I have any but I still need to know what it is

Thanks for the help guys
G

 

[jsteiger]

+48v (TL783C) reg is grounded to same heat sink it is screwed to

Only the 2 negative reg's should have continuity between their metal tabs and ground. Dbl check this. If the 48V reg does indeed have a very low resistance to the heatsink side, remove the screw and very slightly bend it physically away from the heatsink and try firing it up again.

 

[okgb]

It's not hard to over torge the regulator heat sink screws and see the insulator curl ,
better to use some silicon grease and know you have good conduction .

 

[Toure14]

It's not hard to over torge the regulator heat sink screws and see the insulator curl ,
better to use some silicon grease and know you have good conduction .

So if my seal pads are ripped or bad I can use silicone grease as a replacement?

 

[kante1603]

Or just replace it don't overtight them,hahaha.....seriously,it's easy to damage them,I did that on my very first build too,but I always measure if there's continiuity to chassis after assembly.
There are also ceramic pads existing which are a bit more rugged.
Also look at the plastic isolating washer for damages.
Cleaning the backside of the reg as well as their mounting place is a good idea too.

Best,

Udo.

 

[gyraf]

Can anyone confirm that using the LM350T in a negative-voltage configuration like this is really kosher?

I'm trying to wrap my head around TWO 51x-supplies who both killed their -16V supplies (preamp Lola, running of +/-16V lines, she herself seemed to survive) while patching them in/out by patchbay.

What I'm asking is - can we really rely on the LM350T fail-safe and protection circuits, when it's configured like this? I haven't seen it used like this in data sheets.

Been looking at internal IC schematic, but it's quite hard to "reverse" working voltage polarity while analyzing.

Jakob E.

 

[okgb]

No , the grease does not replace the insulator , I meant using it may help you not feel the need
to over tighten it .

 

[jsteiger]

I am not sure what inspired Volker's original design/layout but Doug Self has a couple of similar versions published.

 

[Toure14]

So I removed the seal pads and hardware as Jeff suggested, then bent each positive Regulator forward and fired my PSU back up. Everything worked smooth...I got the lights and all the voltages and most importantly no pops and sparks...