What about using a multimeter set to AC volts to look for ripple? What kind of meter do you have? Sean On Sat, Sep 5, 2009 at 10:22 AM, Carl Denk wrote: > Thanks for the quick reply. The closest thing to a o-scope I have is the > PC sound card plus Zeitnitz's software > http://www.zeitnitz.de/Christian/index.php?sel=3Dscope_en > Would have to make a voltage divider to get the 5 volt down below 1 > volt, but that's no problem. Do you think that will work. The other > quick option is, I have a couple of 1000ufd caps (that's the present > value), they are larger, and have leads out both ends (existing ones > stand up on the PCB), but I could temporarily solder them in to see what > the effect is. Otherwise I would have to order from Mouser or someone. > > I had previously looked at all caps for bulging, or other deformation, > and there is none. > > ps: will be gone from the PC for a couple of hours, then around for most > of the day. > > > > > enkitec@gmail.com wrote: >> Carl Denk wrote: >> >>> Disconnected cable from power supply board to video board, and the 5 >>> volt supply measured at 5 volts. Used a 20 ohm resistor to create a 1/4 >>> amp load, still had 5 volts, changed to 10 ohm resistor for 1/2 amp >>> load, and the 5 volt was back to a couple of tenths volts. I'm assuming >>> that some regulator chip is shutting down due to over current, but am at >>> a loss where to go from here. >>> >>> >> >> =A0 =A0 Suggestion: >> >> =A0 =A0 Verify ripple at 5V output at 20 ohm load. >> =A0 =A0 If excessive, replace the 5V filter capacitors. >> >> =A0 =A0 Mark Jordan >> >> > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- = http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist