Soundcraft Spirit 328 digital power supply

[Ranjez]

Originally Posted by grtstrm

Hi everyone, thank you very much for your suggestions, here is where I am today, unit #1 had an original version power supply. The UCC3810 power manager chip was malfunctioning due to one of the two MOSFETS failing. The MOSFET that is on pin 3 of TX2 shorted to ground during the failure. I am guessing that unbalanced the circuit popping the other MOSFET. I checked the transformer coils to be sure we didn't take those out, and replaced the Bridge. The UCC3810, and the two MOSFETS were removed and replaced. Voila! we have a working power supply.

Unit #2 had been sent back to Soundcraft for the $800 repair (ouch). They replaced the whole PSU with a new one. This has failed, and it is out of warranty. This new version is not as complex as the old version, but it is still cheesy. two resistors are burned to a crisp, and the fuse is still good. Hmmm. I am trying to locate the schematic for the new version, the part number is S-S2005A-04. I have a call in to Soundcraft to see if they will share.

We have a third console, unit #3 that has failed as well, and it just went back to the factory. when that one went, the studio was facing shut down. fortunately the parts came in on time for the first one, so down time was minimized to the swap out.

In the meantime, I have ordered up some commercial grade power supplies, switching for the logic and LED's, and motor, and a super clean linear +15V and -15V 2A balanced, .05v ripple under load for the analog section. With a box and some fit it together bits and pieces, it has come to ~$400. About half of what Soundcraft wants for theirs. Everything should be coming in today, so in a week or so, we will know if this is a viable solution. I'm not dissing Soundcraft for putting a $40 power supply in a $4500 console, but, we may have a little better solution for those that want to keep using these mixers.

Any questions, feel free to ask!

I'd like to see the parts list and /or have you build a power suppy since it seems like mine is starting to fail.

[zak69]

Still having booting problems with 324 Live.
+5V-line is ok, but is it normal that power gives on the boot +17V-line only 14,95 volts?
And does anybody knows is it possible to update the firmware even it won´t boot, could it be some corrupted data in there? Worth of try or waste of time

[thearoom]

My 328 stopped working again. last year brought it local. they said the power supply must have shorted had to jump the board cause it burnt up. now bout 1 year or 2 later. it started having booting problems and now just doesn't do anything...
I ordered a Mackie. I just use the board for routing and I liked the 8 bus. but its very hard to find a small 8 bus board. also the light pipe i can't fond anymore either. anyone know a replacement board reasonable with similar routing features???
I'm selling this one for parts. it all work perfect except for the power supply thing??
thanks

[zak69]

Originally Posted by thearoom

My 328 stopped working again. last year brought it local. they said the power supply must have shorted had to jump the board cause it burnt up. now bout 1 year or 2 later. it started having booting problems and now just doesn't do anything...
I ordered a Mackie. I just use the board for routing and I liked the 8 bus. but its very hard to find a small 8 bus board. also the light pipe i can't fond anymore either. anyone know a replacement board reasonable with similar routing features???
I'm selling this one for parts. it all work perfect except for the power supply thing??
thanks

Hi! I´m interested to buy some parts from you, i have 324 live but they have so many similar parts, can you contact me by email?

jklaakso@gmail.com

[LeeYoo]

Hi all.
Have repaired hundreds, if not thousands of SMPS's (but not this one). Here some thoughts.

SMPS's have a few common problems.
Dry joints on HOT items, like power transistors, diodes, and resistors.
Dry joints on HEAVY items, like transformers. Sometimes cracked tracks from being dropped.
Always reflow those joints with fresh solder with every repair!
You don't always see the small hairline cracks around the pins.
A failing joint can blow up the supply without any warning.

Failing caps from external heat (near heatsinks).
Maybe manufacturers put them there for a reason....
And failing caps from HF ripple currents. Caps heat up on the inside, and spill their guts.
Clean up with alcohol if needed.

Failing caps usually don't blow up the supply, but give operating problems.
The supply might not start, or the unit might only work after warming up, etc..
The failing caps are USUALLY the small ones (under 47uF).
Don't muck around here. Just replace ALL of them.
And don't think those SMD's that look like electrolytics are any different.

If you can, replace with the SAME VALUE, but one step higher in VOLTAGE RATING.
These are slightly bigger, and contain more juices inside, to last longer.

Caps in SMPS's have to be replaced with high quality LOW ESR caps. A common cap will fail in a short time.
Secondary smoothing caps can also fail, and a lower rail voltage (with HF ripple) is the result. Common on motherboard CPU supplies.
Measure HF (scope) on those caps if you can.

A final warning. Mains voltage SMPS's do bite, and kill.
If unsure, let a proper tech handle this.
Leo..

[loopzilla6]

Hi -

I have had good success repairing the old-style power supplies (the one completely enclosed). I have had my 328 in service for over 10 years and couldn't be happier. When one thing goes in the PSU it starts a cascade that causes a breakdown in several other circuits. The fix is relatively easy and can be done in about 2.5 hours.

PM me for more info - happy to help keep these fabulous consoles alive. They really do sound better than most other 8-bus consoles.

[NRG70]

Hello,

does your solution include having it brought to you in Manhatten,
or is it something that you could and would be willing to be sharing with other 328 owners across the world...
if it is relatively easy, why not post a how to tutorial
or something in that order.

a "dead 328" owner in Netherlands

Originally Posted by loopzilla6

Hi -

I have had good success repairing the old-style power supplies (the one completely enclosed). I have had my 328 in service for over 10 years and couldn't be happier. When one thing goes in the PSU it starts a cascade that causes a breakdown in several other circuits. The fix is relatively easy and can be done in about 2.5 hours.

PM me for more info - happy to help keep these fabulous consoles alive. They really do sound better than most other 8-bus consoles.

[thearoom]

I have a dead 328 now. Two years ago when it first died, they say the board burnt around the power supply. They jumped it . And it worked but it's dead again. Where can one get this fixed for a fair price?
Thanks please e mail...