[mythtv-users] HDHomeRun Died

Brian Wood beww at beww.org
Mon Nov 9 20:03:00 UTC 2009

On Monday 09 November 2009 12:48:17 Richard Shaw wrote:
> On Mon, Nov 9, 2009 at 1:33 PM, Eric Sharkey <eric at lisaneric.org> wrote:
> > On Mon, Nov 9, 2009 at 2:29 PM, Brian Wood <beww at beww.org> wrote:
> >> On Monday 09 November 2009 12:07:32 Mitch Gore wrote:
> >>> Hi,
> >>>
> >>> I have had my HDHR since its initial release approx.  (2007ish)  over
> >>> the weekend all the suddon it quit working.  Only power light turns on.
> >>> SiliconDust says its a hardware issue and I need to replace.  I was
> >>> thinking about cracking it open and seeing if i could see what was
> >>> wrong. Anyone tried this?  Success?
> >>
> >> The first thing I'd check is the power supply (wall wart). Although your
> >> power LED illuminates, it's possible you are getting insufficient
> >> current. If this is the original power brick, and you have never
> >> replaced it, this is a very likely scenario.
> >
> > That's just what I was about to say.  When I had this problem earlier
> > this year, SD replaced my wall wart at no cost, despite the fact that
> > the unit was out of warranty.  It's been working fine since then.
> >
> > If you can find a compatible plug lying around (I used one from an
> > ethernet switch), it's an easy thing to test.
> Just make sure it has enough amps and the correct polarity or you may
> fry something.

A well-designed unit should have series diode on the power input to prevent 
reverse polarity being applied to the circuit.

Some designs, especially older ones, use a reverse diode in shunt across the 
DC input, which will then conduct and thus "crowbar" the power supply, 
causing it to blow its fuse, or itself if insufficiently fused. Often there 
is a fuse inside a wall wart, replaceable only be cutting it open.

But the advice is well given, check voltage, current capacity and polarity 
before using a "foreign" power adapter.

Brian Wood
beww at beww.org

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