Hello There the Scenario shown seems to indicates several problems : at first i suggest you to recap completely logic board , even if the capacitors ( 47uF16 v) apparently look good i'm pretty sure they are gone ( if you are good with soldering is not so difficult ) Logic board must be washed very good ( with isopropyl alcool )after having take off old capacitors , then take a look to traces if you see broken and check continuity with multimeter Replace with new capacitors and good luck. But if i understand it seems that you have also a problem with analogic board ( no fan , no video) it should be important to check voltage ( maybe flyback transformer fail) or capacitors inside power supply are gone. If you are resident in USA the best way is get in touch with Charles Phillips ( www.maccaps.com) you can find capacitors references and also ask for a complete recap service ( is one of the Best in the World) Good luck!!

Hello There open computer and take off ( disconnect PSU) under keyboard you'll find ram module , check if the module is well fitted inside its bay , try taking it apart and then fit it welling its bay and then restart computer

hello very common failure in these machines : LCD caps and inverter caps are gone , must recap lcd screen and inverter with new capacitors , i solved this problem with all my powerbooks 140-145b-160 see this video :https://www.youtube.com/watch?v=XP-fWaDb...

hello very common failure in these machines : LCD caps and inverter caps are gone , must recap lcd screen and inverter with new capacitors , i solved this problem with all my powerbooks 140-145b-160 see this video :https://www.youtube.com/watch?v=XP-fWaDbv5s

i followed this guide but i replaced original 3,5 hard drive with ssd and i replace optical drive (PATA) with a 2,5 hard drive 500gb 7200 rpm sata with an adapter bay

and made fusion drive, now iMac start in 15 seconds and it come back to life