i was hoping M5 (or someone else) might know of a place locally that does a mix of electrical work. i had a customer drop off a large LED sign board that runs off 220V mains with seriesed 110V inverters into about 88 separate micro controller boards that run off 24/12/5.6V and control small segments of RGB led's.  the panel blows breakers upon power up. its beyond the scope of work that we do at my shop and wanted to give the customer and idea of maybe where to go.

I would contact the manufacturer of the board for a schematic diagram or a recommended repair shop.

defunct, its an older item

One or both of the power supplies is shorted.  They should also not be run in series.  That's a giant no-no.  Disconnect the loads, then run 110 to each  power supply and test.

BTW, just look for a quality sign shop.

I've never looked as I would just do that myself normally.  Sorry I can't give you a reference.