I have 2 multimeters, both do AC volts, down to the mv range, one has RS-232 to the PC, good thought. I'm assuming anything over say 0.1 volt amplitude would be too much ?? Both meters are what I would call, mid range quality Sean Breheny wrote: > 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=scope_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. >>>> >>>> >>>> >>> Suggestion: >>> >>> Verify ripple at 5V output at 20 ohm load. >>> If excessive, replace the 5V filter capacitors. >>> >>> 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