Jurbo Posted September 17, 2004 Report Share Posted September 17, 2004 I tried to build the circuit to use the C64 PSU for my MBSID project, but ran into problems. After first building the circuit, my output voltages were 5,5 V for both the 5 V and 14 V lines. I noticed a break in the circuit, and soldered it. After this, I lost voltage on the 14 V line almost completely (0,2 V or something). When I measured from the PSU plug, the AC lines didn't show any voltage. ???Did I just fry my PSU? I haven't opened it yet, and I'm truly hoping that there is a fuse for the 9 VAC line?Could a voltage regulator soldered in a wrong orientation have caused this? What is the pinout for ST 7809 voltage regulator? I built the circuit assuming that when facing the text printing, the left leg would be pin 1, middle 2, right 3 (the ST logo would be above pin 1).And what would be the symptoms of fried capacitors?And should I have connected the "end of the line" cap before I began measuring the circuit?Thanks! Quote Link to comment Share on other sites More sharing options...
pay_c Posted September 17, 2004 Report Share Posted September 17, 2004 Good chance that you fried it, yeah. Just measure it without being connected to the SID if there´s still voltage coming out.There is a fuse in the PSU (screwed - somewhere at the side), but I don´t know if it reacted soon enough.Pinout: I don´t know exactly now, but in the schematic/PCB, the big line of the 78xx is the metal on the back.Fried caps: *BURN* *BOOM* Especially Electrolytic ones.That end of line cap should be connected, cause it´s filtering the AC out. Greetz! Quote Link to comment Share on other sites More sharing options...
Jurbo Posted September 18, 2004 Author Report Share Posted September 18, 2004 Got some new fuses today, thank God the PSU was ok and I had fried only the 1,6A fuse of the AC side! I'm so relieved about that!I took the construction apart and started over, adding a part after another. I did nothing different than the first time (well I changed the order of the filter caps on the 9V line, but this shouldn't matter in a parallel wiring, right?). And you know what, the damn thing works now!So now I'm on the track again. Thanks for the mental support, Pay-C! 8) Quote Link to comment Share on other sites More sharing options...
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