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Replacement Soundcraft Mixer Internal Power Supply (S-S2006A-005).

UK/Europe - 220/240VAC 50Hz Model - Now available in a 110VAC 60Hz SPECIAL version for the USA Market!

Have you got one of these Soundcraft EPM or EFX Mixing Desks?

Soundcraft EPM Range

Then - inside the unit you will have one of these.

It is a Switch Mode Power Supply known as the S-S2006A-05

Burnt Out PSU Rear of Burnt Out PSU
Sadly, as you can see, this one has exploded and burnt out lots of its' internal components damaging the circuit board tracks as well (quite a common problem for this unit!).

Below is the ellusive official Soundcraft circuit diagram for the EFX range of the S-S2006A PSU showing the additional Pin 6 on the Harwin Connector.
Most repair engineers will now be getting their copy and paste fingers out as this diagram is not common place as it seems to be only available in one Soundcraft publication.

EFX PSU Circuit (6 Pin Harwin Connector Output)
Having repaired a number of these internal Power Supplies - it struck me that the reliability of this design seemingly leaves a lot to be desired.
So much so that if this common place explosive collapse were to happen during a gig - then there would be many red faces as silence would follow!

There are a few benefits for using a Switch Mode Power Supply:
Automatic 110V / 240V AC Mains Supply
Low Heat generation (unless it explodes through component failure!)

An interesting article on this PSU can be found: BY CLICKING HERE so I will not repeat all of the ins and outs that this excellent blog describes.
New Linear PSU
Maybe you will need one of THESE - Hover and you will see the advert - available on Ebay!

How do I take the unit apart??

It is quite a simple yet laborious business.
Note - best to keep all the screw types seperate as some are self tappers and side and bottom fixings are M3 / M4 threaded screw types

Firstly undo the 13mm nuts on all Jack Sockets
Firstly undo the 13mm nuts on all Jack Sockets.
Note take each plastic washer off too
Note take each plastic washer off too.
Unscrew all the XLR retaining self tappers keeping the small washers too
Unscrew all the XLR retaining self tappers keeping the small washers too.
With all top screws and nuts off - unscrew the lid side screws
With all top screws and nuts off - unscrew the lid side screws.
Keep these bits for reconstruction
Keep these bits for reconstruction.
Remove the Top Panel
Remove the Top Panel.
Locate the PSU Harwin connector cable
Locate the PSU Harwin connector cable.
Gently pull the Harwin Cable connector from its socket
Gently pull the Harwin Cable connector from its socket.
Unscrew all the Silver plated screws holding the circuit board to the base
Unscrew all the Silver plated screws holding the circuit board to the base.
The main board can now be removed
The main board can now be removed.
Unscrew the PSU Top Panel Protective Plate Back screw
Unscrew the PSU Top Panel Protective Plate Back screw.
Unscrew the IEC Socket Fixings and Board Retainer
Unscrew the IEC Socket Fixings and Board Retainer.
Unscrew the EARTHING Nut
Unscrew the EARTHING Nut.
Unscrew Protective Plate Top screws
Unscrew Protective Plate Top screws.
Remove the PSU Top Panel Protective Plate
Remove the PSU Top Panel Protective Plate.
Remove the old PSU
Remove the old PSU.

Has the Blow-Up caused Damage to the Main Mixer Board?

An important thing to remember is that if the PSU has blown up like the one shown above then you should measure each DC rail feed going to the master mixer board.

After visual checks on the main board(s) then:

Checks can easily be done by using the miniature Harwin interconnect wiring harness - disconnected from the PSU - and connected to the master mixer board.

Using a standard Digital meter on the 2K or 20k Ohms setting - you can easily poke 1/8 Watt resistor legs into each Harwin Socket position to measure.

The resistors used here are 0 Ohm so measuring either the leg or through the resistor is the same.

Firstly measure the Earthing Connectivity. We want to see 0 Ohms showing the earths are all connected.

Earth (Pin3) to Jack Earth Earth (Pin3) to Jack Earth Earth Pin3 through the cable and Board Connections back to Pin4
Next measure each of the rails for short circuits to earth (we do not want any 0 Ohm readings).

Note the +48V (Phantom) Rail will show high resistance with the Phantom Switch OUT - this normal.

The Phantom Power circuitry (Harwin Pin 1) will only be engaged when the switch is IN/ON. The meter climbs from low resistance because it is charging/discharging the capacitor/resistor networks that are connected to the +48V pins for the Mic inputs on the board.

Phantom Power (Pin1)should be open circuit Phantom Rail (Pin1) Phantom Switch IN - Reading Starts Climbing Phantom Rail (Pin1) Phantom Switch IN - Reading keeps Climbing
Any near short readings from any of the rails will need investigation prior to connection to our NEW power Supply!!! Good Luck - the Integrated Circuit OP Amps are tiny and difficult to change!!!!!! Look at all the electrolytic capacitors first when fault finding!!!

Positive Rail (Pin2) No shorts Negative Rail (Pin5) No shorts
The +15V (Pin 2 / Ground around 4.5k Ohms) and the -15V (Pin 5 / Ground around 500 to 650 Ohms) readings shown are average for an EPM12 board. You may get slightly different readings for the smaller range of mixing desks.
Remember on the EFX units you will also need to check for NO SHORTS on the Harwin pin 6 to Ground.

Once you have checked all around the master boards - then we can concentrate on the New PSU itself.


Let's consider using a Linear Power Supply to replace the S-S2006A Switch Mode.
There are a number of DC voltages required by the Mixing Desk:

+48V DC (Phantom Power for condensor Microphones) (Harwin Connector Pin 1)
+15V DC (amplifier positive rail) (Harwin Connector Pin 2)
Ground/Earth (Harwin Connector Pins 3 & 4)
-15V DC (amplifier negative rail) (Harwin Connector Pin 5)
(EFX 6, 8, 12 & 20 Models Connector Units only:)
+8V DC (power to EFX board) (Harwin Connector Pin 6)

The same PSU is used in the straight mixers and the EFX models. The only difference is that the EFX models use a 6 pin version of the difficult to get Harwin interconnect sockets and the straight mixer versions use a 5 pin.

The pin connections are the same - the most important thing to remember is that the denoted Harwin Pin 1 (the red line on the cable) is the +48V connection.
It is important to get the Harwin connector in the correct way round and inserted correctly into any replacement board.

The current consumption of the mixer is less than 1 amp - so standard Linear PSU components may be used

Let's design a linear Power Supply which can supply the voltages and current required by the mixer - keeping the size of the circuit board exactly the same as the original unit.
Source a suitable Toroidal Transformer to deliver the current required while keeping the size down so that it will fit in the limited space within the casing.
The limiting factor of this design is that the input Transformer requires 220/240VAC - yet for the UK and most of the Euro market - why worry?

Once prototyped, lets get a circuit board manufactured (same size and fixings as the original S-S2006A-05).

The Hong Kong based board manufacturers I use give excellent fast service. BOTECH CIRCUITS
The Director - Bo - has a wealth of knowledge and checks each design - questioning any particular points she has found prior to manufacture.

Simply create the board you need with CAD CAM software (I use Circuit Wizard), generate the GERBER files via the software, then email them over to botechcircuits@gmail.com and within a week or so you will receive the finished double sided thru the board plated units back!
Super BOTECH Boards - Twice the thickness of the original and VERY High Quality!

Circuit Board Top Circuit Board Back
The Replacement Power Supply.

The new Linear Power Supply for the EPM and EFX ranges of Soundcraft Mixers is now available on Ebay.

The kits are pre-tested prior to despatch - so any failures will be down to damage to the main circuit boards caused by the old PSU failure.

As the new PSU Circuit board has been designed as a one to one replacement, then the fixings inside the base chassis are the same as before. The only difference is that the Toroidal Transformer needs a hole drilled in the base to accept the Toroidal fixing screw kit supplied (see below).
The ReelAudio Replacement S-S2006A PSU with Mounting Kit The ReelAudio Replacement S-S2006A PSU

Installing the Power Supply.
The following pictures show the processes of installing the New Power Supply.
Locate the old base Isolator Strip
Locate the old base Isolator Strip and unscrew the Heat Sink Self Tapper.
Re-install the 2 plastic screws (and nuts) to the IEC Socket and the Heat Sink Self Tapper
Re-install the 2 plastic screws (and nuts) to the IEC Socket and the Heat Sink Self Tapper.
Locate the Toroidal Fixing Kit
Locate the Toroidal Fixing Kit.
Offer the unit into the base plate and mark a hole for the Toroidal. Drill a hole for the Toroidal Bolt fixing.
Offer the unit into the base plate and mark a hole for the Toroidal. Drill a hole for the Toroidal Bolt fixing.
Install the Fixing Kit. Bolt - Flat Washer on underside. Rubber Washer - Toroidal - Rubber Washer - Plate - Flat Washer - Spring Washer - Nut.
Install the Fixing Kit. Bolt - Flat Washer on underside. Rubber Washer - Toroidal - Rubber Washer - Plate - Flat Washer - Spring Washer - Nut.
Loosely install the 2 large self tappers into the IEC Socket. Older models have 2 x nuts and bolts.
Loosely install the 2 large self tappers into the IEC Socket. Older models have 2 x nuts and bolts.
Locate the Top Screening Plate - we need to drill out the old fixing thread
Locate the Top Screening Plate - we need to drill out the old fixing thread.
The thread is now drilled out
The thread is now drilled out.
Locate the top plate - sliding the right angle between the base plate and PSU heat Sink. Fix the Top Plate with 2 x threaded screws
Locate the top plate - sliding the right angle between the base plate and PSU heat Sink. Fix the Top Plate with 2 x threaded screws.
Locate the 2 x self tappers supplied with the kit
Locate the 2 x self tappers supplied with the kit.
Gently screw the self tappers into the heat sink fins making sure the PSU is aligned properly - tighten the IEC Socket screws
Gently screw the self tappers into the heat sink fins making sure the PSU is aligned properly - tighten the IEC Socket screws.
Dont forget to tighten up the Earthing Nut
Dont forget to tighten up the Earthing Nut.
Locate the Harwin Power cable onto the Mixer base board
Locate the Harwin Power cable onto the Mixer base board.
Having re-screwed the circuit boards back to the base plate - you can now power up for a test!
Having re-screwed the circuit boards back to the base plate - you can now power up for a test!
Once Checked - reconstruct the entire Mixer and go Gigging
Once Checked - reconstruct the entire Mixer and go Gigging.

Warranty:

The ReelAudio Replacement Soundcraft Power Supply (S-S2006A-05) is guaranteed for a period of 12 months from the date of purchase.
Normal Usage is implied by the word 'Guarantee' and 'Warranty'.

Click Here to view the Products & Pricing Page.

All Warranty repairs are undertaken on a return to base principle.
Any carriage costs are the responsibility of the Client

REELAUDIO MAKES NO WARRANTY, EITHER EXPRESS OR IMPLIED WITH RESPECT TO ANY PRODUCT, AND SPECIFICALLY DISCLAIMS ALL OTHER WARRANTIES, INCLUDING, WITHOUT LIMITATION, WARRANTIES FOR MERCHANTABILITY, NON-INFRINGEMENT AND FITNESS FOR ANY PARTICULAR PURPOSE. REELAUDIOS' SOLE OBLIGATION AND LIABILITY FOR PRODUCT DEFECTS SHALL BE, AT REELAUDIOS' OPTION, TO REPLACE SUCH DEFECTIVE PRODUCT OR REFUND TO BUYER THE AMOUNT PAID BY BUYER THEREFOR. IN NO EVENT SHALL REELAUDIOS' LIABILITY EXCEED THE BUYER'S PURCHASE PRICE. THE FOREGOING REMEDY SHALL BE SUBJECT TO BUYER'S WRITTEN NOTIFICATION OF DEFECT AND RETURN OF THE DEFECTIVE PRODUCT WITHIN NINETY (90) DAYS OF PURCHASE. THE FOREGOING REMEDY DOES NOT APPLY TO PRODUCTS THAT HAVE BEEN SUBJECTED TO MISUSE (INCLUDING WITHOUT LIMITATION STATIC DISCHARGE), NEGLECT, ACCIDENT OR MODIFICATION, OR TO PRODUCTS THAT HAVE BEEN SOLDERED OR ALTERED DURING ASSEMBLY, OR ARE OTHERWISE NOT CAPABLE OF BEING TESTED, OR IF DAMAGE OCCURS AS A RESULT OF THE FAILURE OF BUYER TO FOLLOW SPECIFIC INSTRUCTIONS.

IN NO EVENT SHALL REELAUDIO BE LIABLE TO THE BUYER OR TO ANY THIRD PARTY FOR ANY INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL, PUNITIVE OR EXEMPLARY DAMAGES (INCLUDING WITHOUT LIMITATION LOST PROFITS, LOST SAVINGS, OR LOSS OF BUSINESS OPPORTUNITY) ARISING OUT OF OR RELATING TO ANY PRODUCT OR SERVICE PROVIDED OR TO BE PROVIDED BY REELAUDIO OR THE USE OR INABILITY TO USE THE SAME, EVEN IF REELAUDIO HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

Units are Designed and Hand Built by:
Paul Baldwin
www.ReelAudio.Co.UK
BaldwinHiFi.Co.UK
12 Tack Lee Road
Yapton
Arundel
West Sussex
BN18 0HB - UK - Great Britain
Direct EMAIL: neverfinished0@hotmail.com
Tel: 01243 553231 - Mobile: 07858 089421
Paul will be unavailable from 27th June 2017 (for 10 days) while installing wiring and equipment into a new HiFi Venue in Ibiza
Please note: Paul may be contacted by telephone during his preferred admin period of between 5pm and 8pm. Thankyou.

Payment for Goods: PAYPAL Account: neverfinished0@hotmail.com
Please specify what you are buying within the PAYPAL Message Area when Making a Payment.

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