Same model with forum member with same problem. We diagnosed it to one electrolytic cap before power amp and one BC547 transistor. That's all. Follow track after input selection switch. in preamp section if your power amp and PS is okay.hi model is stereo System AF 592, I have posted one reply with full technical specification and picture also , hope you can see that post. it was bought around 1980 Picture can please be down loaded http://dl.dropbox.com/u/3554856/philips.JPG
From my experience with vintage indian philips equipment, if the power supply unit, connectors, pots and wiring is ok, it can only be 2 things, 1) blown semiconductors, 2) blown electrolytic caps. You'd need some very basic knowledge of electronics to test these. Spare parts are readily available in the local market.