Digest for sci.electronics.repair@googlegroups.com - 6 updates in 4 topics

ohger1s@gmail.com: Feb 11 06:07AM -0800

On Saturday, February 11, 2017 at 12:51:10 AM UTC-5, Phoena Greene wrote:
I put the Sony in the sink and plugged it in and
> hammer. About ten smashes and it looked like a Hyundai totaled in a drunk
> driving accident.
 
> Rest in pieces, Sony blu Ray Player.
 
Around here, you can't have AC anywhere near water without a ground fault so you would need an extension cord.
 
OTOH, if it fits, remove the top cover and place the offending equipment in the microwave oven if you want a real visual treat....
thekmanrocks@gmail.com: Feb 11 08:21AM -0800

Destroyed a perfectly good player while
the real blame lies with sites like Hulu and
YT constantlh "updating" their smart TV
apps.
"Dave M" <dgminala@mediacombb.net>: Feb 11 09:34AM -0600

> somthing thats 60 years old, and waiting for smoke..... (if there is
> a problem).
 
> Thanks
 
 
Not a good idea to try to reform the electrolytics this way. The reason is
that the rectifier tube won't start conducting until the Variac voltage is
pretty high, and if the electrolytics are very leaky, you risk damaging the
power transformer due to excessive current.
 
Best way to attempt reforming the electrolytic filters is to remove the
rectifier tube, then disconnect the wiring from the electrolytics. Then,
apply a current-limited DC power supply directly to the capacitors, slowly
bringing the voltage up to the normal operating voltage. Be sure to monitor
the leakage current through the capacitors, not letting it get much above
about 10mA or so.
Reforming time could vary considerably, depending on the condition of the
capacitors. If they are too dried out, it might be impossible to reform
them, in which case, replacement is the only recourse. Sixty-year-old
electrolytics aren't likely to be good candidates for reforming.
There is likely to be more electrolytics in the unit; treat them the same
way if they are tied into the B+ supply line. Any low-voltage electrolytics
aren't likely to pose such a big risk to the transformer.
 
If you want to limit the risk of damage to the unit, my advice is to replace
the capacitors first, then you can be reasonably sure that you won't damage
the power transformer. The transformer is the single most expensive and
hard-to-find component in the set. By all means, protect it.
 
Cheers,
Dave M
Ralph Mowery <rmowery28146@earthlink.net>: Feb 11 10:38AM -0500

In article <c26t9cde4gr0r0vfcsamfu8am11c1f1eog@4ax.com>,
oldschool@tubes.com says...
> supposed to work, but I dont like the idea of just plugging in somthing
> thats 60 years old, and waiting for smoke..... (if there is a problem).
 
> Thanks
 
Forget about that variac and just put about a 100 watt lightbulb in
series with the set. Turn the set on. If the light bulb is burning
near full brightness after a few seconds, pull the plug and look for
problems. If the bulb is not very bright, make sure you have a fuse in
the set for the rted value and plug the set in.
 
If the set had a solid state rectifier tube, you could pull all the
tubes and use the variac to see if the capacitors were shorted or some
other problems.
Robert Roland <fake@ddress.no>: Feb 11 02:15PM +0100


>>"It seems to me, the cheaper it is, the higher the chance of finding a
>calibration pot inside."
 
>Your theory is blown out of the water, sorry. Those $0.000 ones from Harbor Freight have no pot.
 
You did not read what I wrote, did you?
 
I spoke of chance, and you refute my claim based on one single sample?
 
Not exactly solid statistics.
--
RoRo
oldschool@tubes.com: Feb 11 06:04AM -0600

On Sat, 11 Feb 2017 03:31:33 -0600, Foxs Mercantile <jdangus@att.net>
wrote:
 
>On 2/10/2017 11:08 PM, oldschool@tubes.com wrote:
> > Where can I get a FREE schematic for a Hallicrafters SX-99?
 
><http://www.myvintagetv.com/Apple%20PDF%20files/Hallicrafters_SX99.pdf>
 
Awesome. Everything I wanted a more....
 
Thank You!
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