Hantarex US250 PSU started to make buzzing noise

[Jakey212]

My Electrocoin NeoGeo is powered by a hantarex us250 which has suddenly started to make a very unnerving buzzing sound. It's working fine but worried it's going to go and take my monitor out with it.
Tried reflowing all joints but no luck.
Anyone repaired a US250 that might be able to give some pointers please?
(Video of buzzing PSU)

 

[Rasputin]

Just give the transformer a bang with a hammer.

 

[Jakey212]

Just give the transformer a bang with a hammer.

I'll give it a go. Would still like to replace it but I doubt there's anything out there given the age of it.

 

[stevebm1]

dry joints are common on these,be warned when they go bang they will probably take out the monitor chasis and game board as the voltages go crazy,you are better off putting a standard jamma power supply and seperate monitor iso inside the cab to be honest