Is there any way to test a STK463 Audio Amp chip? (without having some sort of special factory analyzer)?
I had a Marantz SR1000 receiver given to me. I plugged it in, and got a few seconds of hum, panel lights dimmed also. Then smoke appeared. I found the source of the smoke, a small electrolytic cap blew, and left the board wet.
I may try to replace that cap, but I suspect there is more wrong. I dont usually work on anything containing IC chips. And Im sure if that big amp chip is bad, it would be very costly. (Not worth my time or money). But I'd be willing to test it if I know how.
By the way, the power supply is working. As soon as I unplugged it (after the smoke), I got a good spark when I shorted the main (large) filter caps.
on repairing this unit. If the STK is bad, a new one can be obtained for $10-$15.
The blown cap is C807. Its.connected in the area of the Q805 transistor, which I am guessing is a voltage regulator (maybe)???? Appears to be
10uf at 50v.
I have not found a schematic for this unit so I'm in the dark on it.... But this is in the power supply area.
I have watched several videos on YT about similar units that use the STK modules. It seems they work well, until they fry. Then all hell breaks out. The other caution is that many of the after market STK mods are fakes, which do not work.
I will also mention that in the 80's, I worked on a Fisher stereo that had a STK mod. Back then these mods were costly. I bought a replacement, it burned up instantly. (And yes I had checked power supply voltages and all of that before powering it up). Theres a video on YT in which some guy had the same experience. On that one I worked on in the 80s, I spent many hours, and lost a lot of money on it. Actually, that was when I quit working on other peoples gear.
I ended up stuffing a amplifier board inside that stereo, from another device, just so I could hand the owner a working stereo. It worked but only produced around 5watts per channel. The owner was satisfied, but not highly impressed by the low power.
Needless to say, I do not have a very good impression of those STK modules, overall.
Aside from that, since this thing cost me nothing, I'll play around with it, and will stick a few bucks in it for caps and such. After that it will just become a pile of salvagable parts...... While its a nice looking device, its not worth much effort or money to me.
Note: Before posting this i did find a schematic.....