[pvrusb2] Re%3A%20%5Bpvrusb2%5D%20No%20data%20from%20HVR-1900%20encoder&In-Reply-To=%3C1308471515.2019.6.camel%40tyst%3E

[Gary Buhrmaster]

On Sat, Jul 13, 2013 at 6:23 PM, Roger <rogerx.oss at gmail.com> wrote:
> A power volt/amp meter might suffice, because if the power supply is bad it is
> going to likely show fluctuations within either amperage or voltage.

Maybe, but....

> The only thing you're likely omitting are intermittent spikes or unsufficient
> power.

The "cheap" (Hauppauge probably saved a few cents on each power supply)
power supplies usually end up with extremely high ripple voltages under load
due to "bad caps"/"failed caps", although I will agree that occasionally your
bad house mains might be a contributor.  Most of the devices that I have
disassembled show the typical expanded cap that can either be caused by
a bad batch, or, by not using a high enough temperature rated cap into the
(usually sealed) block.  It can get hot in there!  In any case, if you have the
proper power analyzer (with logging) inline you can detect such failures, but
your typical VOM may not be sufficient.  As I said previously, it is often just
easier to "try it" with a new (high quality, if possible) power supply
than to do
the detective work.  In my particular case, I can go find a high
quality (switching)
power supply in the "new-to-me" piles at the local electronics surplus
stores.  it solved the problem in two different HVR-1950's for me (and while
I only opened up one of those failing supplies, the cap was blown; I had
another cable modem power supply with a blown cap, and a switch with
blown caps, and I do not know how many PC power supplies with blown caps).

As I said previously, replacing the power supply with something known
good is an easy first check.

Gary