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Title: Qbert power supply Post by: qrulz on September 27, 2015, 06:59:37 pm I rebuilt my qbert power supply and was checking for shorts using my dmm on continuity and was getting a quick beep when I checked across C21. I believe that the one side should be 30v and the other ground. I checked it several times and I got the.same result half of the time. The beep only lasted a second or two and then stopped. It looked like the reistance was increasing the longer i held the probes. Is this normal? Do I have a bad part? Any suggestions on what to look at?
Title: Re: Qbert power supply Post by: iankellogg on September 28, 2015, 07:50:28 am I am not sure what you are trying to do but you aren't doing it right. Continuity testing on a capacitor isn't going to tell you anything other than yeah its completely shorted and will beep for as long as you hold it there. If you try to measure resistance you are going to get absolutely nothing of value. The cap will charge up and at some point hit full value and resistance will be well in the megaohms.
You should probably post what issue you are having, no power? blowing fuses? Without knowing anything about your problems with your supply im going to just guess you aren't getting 5V which 90% of the time means the 2n3055 is bad. Might not be shorted but it might still be bad. |