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discrepancy: schems vs. DVM reading


rj.phila

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hi folks, im wondering if you can tell me which fork in the road to take:

 

on the attached screen capture, you will see 2 capacitors in the schematic in question. on it, both + sides of the caps are on the RIGHT side.

 

however, on the actual pcb, there are no notations at all. if i read across each cap using a DVM set to DC voltage, the top one has +V on the right, and the bottom one has +V on the left. furthermore, the actual notations on the CAPACITOR are either missing, or covered up by a blue splotch. (this blue splotch also would corroborate that the + of top cap is on right, and + of bottom is on the left).

 

is this sufficient evidence to trust my DVM reading approach when replacing? thanks for the help-rj

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Those are polarized filter caps. Typical application is for one cap to bridge -V to ground, and the other to bridge ground to V+.

 

Since they are polarized, and the positive lead must always be at a more positive voltage than the negative lead, one may surmise that the middle triangular shaped pad is ground, while the pad with the negative cap terminal is V-, and the pad with the positive cap terminal is V+.

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thanks for the reply, mate! yea, i know they are polarized; i just realized that their orientation on the schem doesnt physically match the actual pcb at ALL; on the pcb, + is on right, - on left. i just now realized that the schem shows them top/bottom. i would expect 2 adjacent caps to have - and + to be tied off together to ground, and the schem not matching totally threw me. got it now.

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