I just picked one up at Goodwill. Brought it home and hooked it up, and
activated it throug Comcast. It came up working. Tried running a speed
test from
the Speakeasy site. It started working, then slowed down, down, down, and
finally stopped. Couldn't get it to work again.

Can antone suggest anything I might be able to check to get this working? I did
open it and look at the caps - none are bulging, and a quick ohmmeter test
suggests they act as a cap as I switch the leads back and forth.

Bad caps are still a reasonable suspect... they can go bad in ways
which don't cause them to bulge.

Two ways to check:

(1) Use a capacitor ESR meter (which is different than a capacity
measuring meter). They should show a low ESR - a fraction of an
ohm.

(2) Use an oscilloscope to monitor the voltage across each cap, with
the cable modem powered up (ideally, in actual service). If you
see significant ripple or noise across a power-supply decoupling
capacitor, the cap may be bad.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
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