Stereo Receivers dead after power surge but all fuses intact

[Mienie]

I have two stereo recievers that are dead after a power spike
(high-low on the pole on the corner of my block). I was hoping that it
would be a simple matter of replacing a blown fuse, however, when I
opened them up the fuses were fine. Both the one near the AC cord and
those on the transformer.

Any ideas on what the problem is or where I should start looking? I
have a multimeter though I'm just getting up to speed on how to use
it--and basic electronics! ;-)

The receivers are a Pioneer VSX-454 and a Sony STR-D605. Looking
around for cheap replacements reveals that low-end receivers no longer
have phono inputs and this is a feature I often use so I'm definitely
looking to fix these.

 

[Ken G.]

The power transformers have an internal thermal fuse hidden under the
tape in the windings .
Find the AC input wires on the transformer and test them with an ohm
meter to see if its open .
If you can find the thermal fuse you can jumper it but the trany will no
longer have thermal protection .

You can buy a simple phono pre amp to use a record player off any AUX
input on modern stereos .

 

[Asimov]

"Mienie" bravely wrote to "All" (28 Dec 03 09:46:35)
--- on the heady topic of "Stereo Receivers dead after power surge but all fuses intact"

This is pretty much an initial basic electrical check. The first thing
to check is the AC plug itself using the continuity beeper or the ohms
range. Test each wire separately for conductivity. This seems pretty
basic but often it is automatically ignored by a more experienced
person. One has to use a systematic approach so that we can rely on what
has already been tested with confidence. Then include the fuse, then the
transformer primary, secondary, etc.

I would only then apply power and check for a sign of voltage at the
main supply filter electros using the DC volts range (always start at
the highest range and work down to get a reading). If no DC voltage is
present then I would look for AC at the input to the rectifier using the
AC range. If none is present then something inbetween is open. Be very
careful of live voltage, especially high DC voltage as this can produce
tremendous sparking currents. Good luck!


Mi> From: Mienie <[email protected]>

Mi> I have two stereo recievers that are dead after a power spike
Mi> (high-low on the pole on the corner of my block). I was hoping that it
Mi> would be a simple matter of replacing a blown fuse, however, when I
Mi> opened them up the fuses were fine. Both the one near the AC cord and
Mi> those on the transformer.

Mi> Any ideas on what the problem is or where I should start looking? I
Mi> have a multimeter though I'm just getting up to speed on how to use
Mi> it--and basic electronics! ;-)

Mi> The receivers are a Pioneer VSX-454 and a Sony STR-D605. Looking
Mi> around for cheap replacements reveals that low-end receivers no longer
Mi> have phono inputs and this is a feature I often use so I'm definitely
Mi> looking to fix these.


.... Over a hundred billion electrons were used in crafting this tagline.

 

[Me]

thanks.

JJ

 

[Me]

Thanks!

Jon

 

[Mark D. Zacharias]

You might want to check the smaller standby transformer, though Sony has
discontinued the part for many of those.

MarkZ .