hi there i have the same problem and the same burnt resistor can you list where you got the spare parts also where can you get the whole board the only one I can find is 218 pounds plus shipping which is really more than the unit is worth cheers and thanks for the vid
The two MOSFETs and the 0.056 Ohm SMD resistor seem to be common failure in these amps. It could be the two little fans to blame for overheating, when they age and start to slow down. I ordered new fans and will be replacing them You should be able to get the parts from Digikey UK or from ebay, but Digikey is the reputable source. The original STP14NF12FP MOSFETs are now obsolete, so I used the new substitute suggested by DigiKey that works perfect: STF20NF20 - DigiKey part nr. 497-5811-5-ND Resistor 0.056 Ohm 1W part nr. 311-0.056TCT-ND If you also want new fans, these are: DigiKey part nr. 259-MF50101V3-1000U-A99-ND and DigiKey part nr. 259-1796-ND Desoldering the old parts can be a challenge if you don't have a good solder pump. I damaged one thru-hole and had to make a wire bridge. I left the bad resistor in place and piggy-backed the new one on top of the old. My repair of the fried module went v. well. I will post a new video of it in the next few days.
@@tektech1065 wonderful thank-you m8 have ordered the bits (with a couple of spares ) and will give it a go thanks again for posting the video might get a few more of these back working.
hi again m8 i got all the bits but slipped after finishing and dropped the board and damaged a chip on the back the label 7115 do you know what part this is? on top of the chip is says 1bt its pins are labelled c b e . thanks again for the help
The schematic for the power amp is hard to find on the internet. And the good links often disappear. I found it in music-electronics-forum and 16145-need-yamaha-stagepas-300-schematic/page2 If you google that, you should be able to get the PDF circuit. Good luck!
