Novation Supernova II – Internal Power Loom Issue

Introduction:

The Novation Supernova II can be a tempermental beast at the best of times.
Units may not not boot properly, have system lock-ups, and show general random behaviour.
Some of these issues can be caused by the internal power loom.

The power loom has 6 wires that connect the Power Supply to the Motherboard PCB.

At each end is a 6-Way Molex connector that pushes down onto a 6-Way Pin Header on the Motherboard and PSU.

The photo below shows the Motherboard to the left, and the PSU on the right. The power loom is the multi-coloured cable assembly connecting them.


This loom supplies the +5V, +12V, and -12V power supplies to the Motherboard.
Over time the connection between the cable connectors and the pins on the Motherboard / PSU can get oxidised and this causes a voltage drop at the Motherboard.

The biggest issue is with the +5V supply. This supply is used for the CPU and all the DSP ICs.
If the +5V supply is low at the motherboard then problems can appear. The problems can get worse when the SIIEX24 card is installed as this will draw a further 0.8 Amp from the +5V supply and the voltage can drop even lower.

The photos below show the wires that carry the GND and +5V supply.

Note: The photos are of the Keyboard version. The Rack version uses the same PSU and power loom but it is routed differently in the unit.

Motherboard:


PSU:



Example of Voltage Drop Issue
The photos below show the +5V voltage readings at the Motherboard, and then at the PSU.

Note the voltage drop of around 0.25V at the motherboard connector.

The MultiMeter is reading the Motherboard voltage at the loom connector’s crimp terminals and not the motherboard’s connector pins. The actual motherboard voltage can be lower.
Motherboard Voltage Reading:


PSU Voltage Reading:



At this point it is worth checking the condition of the PSU.
Take a look at the PSU’s capacitors for signs of bulging and / or any leakage.
The photo below shows the items to check:


If the PSU capacitors show signs of leakage then consider having it replaced or refurbished.


Loom Cleaning Procedure

!! Before tampering with the Power Loom please ensure the Supernova is switched off and disconnected from the Mains Supply !!

The voltage drop issue can be resolved by simply removing and re-attaching both loom connectors several times.
This will help clear the oxidisation on the connector pins and may restore the normal voltage at the Motherboard.
If you have a multimeter you should see an increase in the reading of the +5V supply at the motherboard.

If this does not help cure the problem then the loom and connectors will need a thorough cleaning.

Loom and Connector Cleaning:
1. Remove the loom from the Motherboard and PSU



2. Clean the Motherboard and PSU connector pins with a cotton bud and Isopropyl Alchohol (IPA)
If you squeeze the cotton bud with pliers it will fit between the pins and nylon housing.
Clean all four sides of each pin.



3. Remove each wire crimp from the connector for cleaning.
To avoid confusion it is best to work on one crimp at a time.
The crimp can be removed by pressing on the metal retaining tab and gently pulling the wire from the housing.
Crimp retaining tabs:


Crimp removed:



4. Crimp Cleaning and Adjustment:
Use a toothbrush and IPA to thoroughly clean each crimp.
The two connecting tabs may have become slack (arrowed)


Pinch the two tabs closer together so the crimp will have a better grip on the connector pin:



5. Adjust the retaining tab.
Before placing the crimp back into the nylon housing use a small blade to lift the retaining tab up a little so the crimp stays in the housing properly.
The photo below shows how the tab should look before refitting it..



Once all 12 crimps have been cleaned and adjusted you can re-fit the power loom to the Supernova.

After this procedure was completed the +5V reading at the motherboard was normal again.
The voltage drop across the loom is now only 0.01V – a good improvement on the 0.25V before the loom and connectors were cleaned.

Motherboard Voltage Reading with Cleaned Loom:



// Document End

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