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<div class="moz-cite-prefix">On 6/27/20 9:46 PM, DryHeat122 . wrote:<br>
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<div dir="ltr">On Mon, May 11, 2020 at 12:59 PM DryHeat122 .
<<a href="mailto:dryheat122@gmail.com"
moz-do-not-send="true">dryheat122@gmail.com</a>> wrote:<br>
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<div dir="ltr">On Mon, May 11, 2020 at 2:41 AM Stephen
Worthington <<a
href="mailto:stephen_agent@jsw.gen.nz" target="_blank"
moz-do-not-send="true">stephen_agent@jsw.gen.nz</a>>
wrote:<br>
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rgb(204,204,204);padding-left:1ex">On Sun, 10 May 2020
20:20:30 -0700, you wrote:<br>
<br>
>On Sun, May 10, 2020, 7:58 PM Greg <<a
href="mailto:gregl@nycap.rr.com" target="_blank"
moz-do-not-send="true">gregl@nycap.rr.com</a>>
wrote:<br>
<br>
>Ok thanks I will investigate that. But it's been
working fine with the<br>
>current power source for like a year now, and
others on this list use it<br>
>too.<br>
<br>
USB cables often fit badly into the sockets. If so,
the connection<br>
generally gets worse over time as you get dirt or
oxidisation on the<br>
contacts. So badly fitting cables will degrade with
time. The result<br>
is that the voltage drop across the cable will
increase markedly. And<br>
they can be too thin - the amount of copper in the
wires is too little<br>
and that causes high resistance and a big voltage drop
across the<br>
length of the cable. Some (most?) USB cables are
designed only for<br>
data transmission, or to run very low power devices.
For a high power<br>
device, you need a better (thicker) cable. The high
power devices do<br>
a negotiation with device supplying the power and
request high power<br>
mode. If the cable is not capable of high power, that
negotiation is<br>
not supposed to work and the device should either only
work in low<br>
power mode or it should turn itself off. But USB
cable makers often<br>
make cables not capable of high power transmission
that will allow the<br>
high power mode negotiation to succeed. So even
though the device<br>
supplying the power is sending high current, the
voltage drop in the<br>
cable means that at the other end, the voltage can be
below the level<br>
required for proper operation or to fully charge the
device's battery.<br>
<br>
I have had two notably bad experiences with USB
cables. One was a USB<br>
DVB-T tuner, and it was very like your experience - it
would go for a<br>
number of days just fine, then suddenly stop. If I
unplugged it and<br>
plugged it in again, it would usually work again.
When I finally<br>
investigated properly, I found the cable was just a
little loose in<br>
the PC's socket. I replaced the cable with one that
fit more tightly<br>
and the tuner was much more reliable. It still
occasionally caused<br>
trouble, but only when I had bumped the cables (or in
one case, after<br>
we had a small earthquake). So because of that and
because I needed<br>
more DVB-T tuners, I finally replaced all my DVB-T
tuners with an 8<br>
tuner PCIe card.<br>
<br>
The second bad experience was my Samsung Galaxy Tab S2
tablet. Its<br>
USB charging cable was supplied with it by Samsung, so
I assumed it<br>
was a good one. But right from the start, the tablet
took a long time<br>
to charge, and the time gradually got longer and
longer and the<br>
battery life on one charge was getting less and less.
And then I<br>
started to have to jiggle the cable in the socket to
get it to charge<br>
at all. I actually called the Samsung help line about
this, and they<br>
said it sounds like a bad cable. So I bought a
expensive (NZ$30)<br>
Pudney & Lee charging cable, which was a fair bit
longer than the old<br>
Samsung cable, but fit very tightly at both ends and
was significantly<br>
thicker - it has more copper in the wires in the
cable. Then suddenly<br>
the battery charging times were what was specified for
the tablet,<br>
rather than three times as long. And over a number of
charging<br>
cycles, the battery life came back again. So the
original Samsung<br>
supplied cable was clearly bad from the start - it is
probably less<br>
than the specification required to charge the tablet
properly as it is<br>
too thin and has too much voltage drop even when the
plugs fit<br>
properly. So definitely NZ$30 well spent. But I am
surprised that a<br>
reputable company like Samsung would supply a bad
cable with an<br>
expensive top-of-the-line product like my tablet. But
they did - so<br>
now I always suspect any USB cable I get and keep an
eye on how well<br>
it is working.<br>
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<div>Thanks for all the suggestions. I will investigate
all of them. Something I do not see in here is an
opinion that some software problem could have
evolved. I was kind of thinking of that as a
possibility given that it worked fine for so long then
seems to be degrading. OTOH I never thought of the
possibility that the USB connection could be
degrading. I'm going to try Greg's connector,
assuming I can get parts during the Apocalypse. Also,
his link specifies Radio Shack parts. What's Radio
Shack?!? ;-)</div>
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<div>Well folks this is getting frustrating. I addressed a
possible ventilation issue. I also unplugged the power cord
I had from the Myth box USB and connected it to an old iPad
charger rated at 5V/2A. No help. It wouldn't record
anything, no matter how much rebooting and power-cycling.
So I concluded the HDPVR was hosed and got a new one (more
accurately, a replacement circuit board for it). Powered it
with the same wall wart. Recorded great for a day. Just
turned it on and I have failed recordings and it won't
respond when I try to manually play a channel. Reboot, and
it works fine, same pattern as before. </div>
<div><br>
</div>
<div>I finally got a molex connector and am still going to try
what Greg suggested, but I really don't think it's a power
issue. Apply makes good electronics and that wart has the
same specs as the power supply that comes with the HDPVR.
The HDPCR isn't overheating. It's not the HDPVR itself.
That only leaves the software on the myth box. Anyone have
ideas how to troubleshoot that?<br>
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<pre class="moz-quote-pre" wrap="">_______________________________________________
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<p> The next time it won't record,try to cat it and see if it
responds. This is the command I use, cat /dev/video0 > test
.. dmesg for the proper port it's connected to. This may help too
see if it is the software or not..<br>
</p>
<p>I am curious were you got the motherboard? There used to be a
place in Ohio (I believe) ,but they have gone out of business. <br>
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