[mythtv-users] HDPVR died, what should I buy?

[Michael Watson]

On 18/06/2014 1:09 AM, Gary Buhrmaster wrote:
> On Tue, Jun 17, 2014 at 1:54 PM, Fred Hamilton <fred at yonkitime.com> wrote:
> ....
>> I'll second that.  When my hdpvr "died" a few years ago, I probed the voltage coming from the adapter and saw it was low and crazy ripple-y.
> A common failure mode for those (POS) power adapters is that
> the caps fail (heat in a (mostly) enclosed plastic case is the
> death of most (cheap) electrolytics that are used), which results
> in bad ripple.
>
>>   So I cut the cord from the adapter and soldered it to a USB connector.  I found a 5V 1A USB charger, plugged it in, and it's worked like new ever since.
>>
>> Might even work plugged into one of your PC's USB ports...
> 1A is possibly on the low side.  Hauppauge specs 2A,
> and sells a replacement (in the US) for around $10 through
> their web store(*).  I presume the new one has the same
> failure mode as the original, but for $10, another few
> years of use might be an acceptable investment for
> those that do not want purchase something better (or
> resort to soldering).
>
> Depending on the PC USB port (and version), it may not be
> able to provide more than 100ma without negotiation (although
> many dedicated USB charging ports provide more, even
> without negotiation, PC ports may require some amount of
> negotiation).  As with all else, your particular MB will vary.
In/Battery Charging Specification/,[31] new powering modes are added to 
the USB specification. A host or hub Charging Downstream Port can supply 
a maximum of 1.5 A when communicating at low-bandwidth or 
full-bandwidth, a maximum of 900 mA when communicating at 
high-bandwidth, and as much current as the connector will safely handle 
when no communication is taking place; USB 2.0 standard-A connectors are 
rated at 1500 mA by default. A Dedicated Charging Port can supply a 
maximum of 1.8 A of current at 5.25 V. A portable device can draw up to 
1.8 A from a Dedicated Charging Port. *The Dedicated Charging Port 
shorts the D+ and D- pins with a resistance of at most 200?*.*The short 
disables data transfer, but allows devices to detect the Dedicated 
Charging Port and allows very simple, high current chargers to be 
manufactured*. The increased current (faster, 9 W charging) will occur 
once both the host/hub and devices support the new charging specification.

> Gary
>
> (*) Given they sell the replacement adpaters, one can
> conjecture that it is a common accessory that needs
> replacement after some period (usually, right after
> the warrantee expires :-)
> _______________________________________________
> mythtv-users mailing list
> mythtv-users at mythtv.org
> http://www.mythtv.org/mailman/listinfo/mythtv-users
> http://wiki.mythtv.org/Mailing_List_etiquette
> MythTV Forums: https://forum.mythtv.org
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2014.0.4592 / Virus Database: 3964/7691 - Release Date: 06/17/14




-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4592 / Virus Database: 3972/7698 - Release Date: 06/18/14
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.mythtv.org/pipermail/mythtv-users/attachments/20140618/1b3d3a9c/attachment.html>