I'm desperate to save my pair of 2007 KRK VXT6 studio monitors, one of which died.
Hoping for an easy fix, I bought a pair of new-old-stock replacement main boards. I installed one & it was DOA. Tried the other, also DOA. I suspect that 15 years in a Maltese warehouse dried out the electrolytic caps. I tried replacing just the two largest caps, which didn't help. Except to confirm that the old ones wouldn't reach infinite resistance & were a gram underweight.
Q: How do I match the caps, since there's no series marked on the originals and no circa-2007 catalog or datasheets from the mfr TWBOR? I've wrung the web dry over this (wayback archive, patent office, digikey parametric search, ebay, stack exchange)!
I also plan to recap the little “switch” board, too. It runs the status lamp & toggles for auto-mute, ground lift & overload handling (warn, ignore, limit). Its 4 caps have 8080808 printed on them. This corresponds to nothing.
So I'm faced with recapping these boards, based solely on the marked voltage, capacitance, temp rating (all 105c) & physical dimensions. Can someone guess their functions from the pics & tell me at least generally what specs to look for, beyond what's printed on each cap? I don't have a schematic. Nobody seems to, it's been sought here & elsewhere. FWIW: this is a bi-amplification board (30 watts tweeter, 60 watts woofer, 1 mains transformer).
Or better yet, if you've successfully recapped a KRK VXT6, would you send me your shopping list?
Here is my list of caps, numbered according to the PCB. Height may be ±1mm, due to the black goop (which is neither brittle nor conductive).
Hoping for an easy fix, I bought a pair of new-old-stock replacement main boards. I installed one & it was DOA. Tried the other, also DOA. I suspect that 15 years in a Maltese warehouse dried out the electrolytic caps. I tried replacing just the two largest caps, which didn't help. Except to confirm that the old ones wouldn't reach infinite resistance & were a gram underweight.
Q: How do I match the caps, since there's no series marked on the originals and no circa-2007 catalog or datasheets from the mfr TWBOR? I've wrung the web dry over this (wayback archive, patent office, digikey parametric search, ebay, stack exchange)!
I also plan to recap the little “switch” board, too. It runs the status lamp & toggles for auto-mute, ground lift & overload handling (warn, ignore, limit). Its 4 caps have 8080808 printed on them. This corresponds to nothing.
So I'm faced with recapping these boards, based solely on the marked voltage, capacitance, temp rating (all 105c) & physical dimensions. Can someone guess their functions from the pics & tell me at least generally what specs to look for, beyond what's printed on each cap? I don't have a schematic. Nobody seems to, it's been sought here & elsewhere. FWIW: this is a bi-amplification board (30 watts tweeter, 60 watts woofer, 1 mains transformer).
Or better yet, if you've successfully recapped a KRK VXT6, would you send me your shopping list?
Here is my list of caps, numbered according to the PCB. Height may be ±1mm, due to the black goop (which is neither brittle nor conductive).
Code:
Main board caps (all marked 105c) # V uF diam height 1 25 330 8 12 2 63 100 8 15 3 63 47 8 15 4 50 12000 30 53 5 50 12000 30 53 7 25 1000 10 17 8 25 470 8 15 9 25 470 8 15 10 25 1000 10 17 51 50 10 5 10 201 50 100 8 12 202 50 100 8 12 204 25 100 6 10 301 50 100 8 13 302 50 100 8 13 304 35 47 5 13 502 50 10 5 13 nonpolar 505 50 10 5 13 613 50 100 8 12 CA7 63 470 13 22 Switch board caps (all marked 105c) # V uF diam height 401 50 10 5 12 404 50 4.7 5 12 408 25 100 6 12 410 25 100 6 12
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