ESR and capacitor brands: what to trust on a rework

English capacitor practice notes in the spirit of classic “bad caps” bench talk — original NLCRC text, not copied posts. Why ESR matters - Bulk electrolytics on 3V/5V/12V and VRM inputs can look fine yet have high ESR, causing ripple and random resets. - Measure out of circuit when you can; compare to a known-good of the same value. Replacement habits - Match or exceed voltage rating; keep capacitance close; prefer low-ESR / polymer where the design used them. - Mind ripple current ratings on GPU/CPU filters. - Counterfeit or “no-name” bulk packs fail early — buy from trusted distributors. Visual still helps - Bulging, venting, crust — replace the set on that rail, not only the one that exploded. Share photos of the bank, measured ESR, and board PN when unsure.