[Retrotechie]

Hi Phil, yes, the dreaded ‘nichicon’ capacitors leaking, which can damage the tracks and I think in cases of severe damage, short out some of the FETs.
The whole board is coated in a lacquer, which can make soldering a little tricky & unpleasant smell (fume extraction advised).

I think in other other cases, the fault can be caused by the EL panel itself, especially if the seal has gone or one of the mux ICs on the flexible Pcb.
There was a company in the states that offered a repair service but it starts to get costly.

I’ve been unable to source any schematics and used displays seem to fetch high prices, as they used a lot in industrial control (and those horrendous Panasonic VTRs), and sometimes, there’s no modern compatible equivalent that can be sourced/fitted.

I’m in the process of making up some test jigs, so hopefully will be able to fix some more of these.