AVX (?) Tantalum caps giving odd reading - TDS3000B Battery board schematic

[perdrix]

i'm trying to locate the source of some apparent ripple on the trace of my TDS3000B.   All the capacitors on the Artesyn 15V supply appear good, and I'm now looking at the battery board of my TDS3000B.  There are two yellow AVX caps which I think are TAJY156K025RNJ (15uF, 25V, Case Y).

One of them is giving me a very odd reading on my BSide ESR02.  The one to the right (C870) is reported as 987uF, ESR 0.28, while the other (C260) is reported as 16uF, ESR 0.3 (which sounds about on the money).



I suspect that something else in the circuit is confusing the ESR02.  Did anyone ever reverse engineer the battery board circuit?

Thanks
David

[madao]

156E = 15^6 = 15 000 000 pf = 15 µF
E = 25V rating

You're right with value of 15µF

nearly 1 mF = , probably high leakage current has influenced to reading of RCL Meter (?)
Have you desolder and check tantal ?  In ciruit measurement with RCL Meter isn't possible in most case.