Led mirror Ball PSU with no power output

[garrymc123]

Hi Guys got another project here and looking for your advice got a led mirror ball that stopped working so checked power board and doesn't have any voltage on the output side and idea where to check for faults cheers guys

[eccerr0r]

Re: Led mirror Ball PSU with no power output

Did something leak the "magic smoke" when it died (do you smell magic smoke from the circuit?)

What's that TO-92 circuit, is it a transistor? Is it still good?

Are there any ICs underneath the transformer?

[garrymc123]

Re: Led mirror Ball PSU with no power output

Hi, there no magic smoke and no smell from the board the to-92 is 13001 S6B 0 2A 400V high-voltage transistor to-92 plug-in flying electron and the small transistor is a j37 which I can't find any info on.

Any help much appreciated

[eccerr0r]

Re: Led mirror Ball PSU with no power output

Okay, looks like a 2-transistor switching supply. The 13001 is the switching transistor, did that burn out?

[redwire]

Re: Led mirror Ball PSU with no power output

Usually the MJE13001 shorts and blows up.
But there is no fuse here, so I would check all parts for continuity. The transformer primary might have been the fuse...

J3Y marking code is KST8050S

It looks like poor build, the transformer core isn't glued aligned and any problems with it make the circuit not work.

[momaka]

Re: Led mirror Ball PSU with no power output

This thing looks cheaper than garbage! I'd honestly just try to replace it with a different, better quality power adapter. If the LEDs don't have resistors to limit the current, you might have to add those before using another power adapter.

That said, if you still want to try and fix this thing... my guess would be that the 13001 BJT probably either shorted or opened. If there is no fuse, it most likely went open-circuit, because TO-92 transistors can't really handle high currents and will easily blow their junction. Just remove it from the circuit and check it. If you don't see a normal forward diode reading between Base and Emitter/Collector pins or any reading out of circuit between Emitter and Collector pins, it's likely bad.

[kevin!]

Re: Led mirror Ball PSU with no power output

How to comment momaka, look for a good quality replacement. That PSU is manufactured thinking of the cheapest and saving costs. That PSU is a danger.

[sam_sam_sam]

Re: Led mirror Ball PSU with no power output

I would also check the ( M7 ) diode I have seen a few of fail open and some of them short