Repairing SPS for LED lighting

[Richard Sendall]

Hello all, would appreciate some help repairing a power supply for LED lighting.

I have a number of LED strip lights from the company LEDLight.  The power supply has become defective, the symptoms being that the LEDs flash on/off approximately 2/3 times per second and there is a ticking noise from the power supply.  I have checked and confirmed that the actual LEDs themselves work correctly by connecting them to a known good power supply.  The power supply module specification is:
Manufacturer: Ciguan
Model: WL50-23-001
Input: 230v, 215mA
Output: 66v DC, 660mA

I have had no luck in finding any information on the company Ciguan or the model WL50-23-001 and LEDLight do not stock/supply spares.  I have attempted to perform some limited testing and diagnostics on the power supply, it appears to be a simple buck converter with a chopper circuit.  I have replaced all electrolytic capacitors with new ones and have also replaced the output inductors, diode and switching transistor (SVF12N60F) with known good parts from a working power supply.  I have also checked the output of the bridge rectifier across the mains input, I measure the expected 340v (240v x root 2), so it looks like the chopper circuit/controller IC has a fault.  Unfortunately, these components are all surface mount and there's no marking on the IC which is a 6-pin device.

Any ideas on what I could do next?  Whilst the LED lamps aren't very expensive, would be nice to fix it rather than bin it.

Many thanks!