EMT 248 shematics or service manual?

Recently, I had a chance to recover a EMT 248. The unit was covered in dust for years. I cleaned it inside out, then plugged it in. It seems good at first. The front pannel shows everything well and reacts to control accordingly. But after a while, one capacitor starts to puffing smoke.

I've been searching for schematics or service manual. Hope someone could provide one. Thanks!