This is an Insignia Model: IS-HTIB102732 progressive scan home theatre DVD
receiver. It was accidentally plugged it into a 220 volt source and
"clouds" of white smoke apparently started coming out of the left hand side
where the power supply is, even though the person who did it says it wasn't
actually turned on. (surely if it was unplugged, plugging it in would put
it into stand-by mode, - it wouldnt try to turn itself ON?)

The wall fuse blew about five seconds after it started smoking.

The unit does however now turn on! And it seems to work. And I cant see
any damage to the power supply area on the left of the unit! Curiously
there is what looks like a fuse on the power supply board which doesn't even
look blown?

The problems for which it has come to me are that it seems to have lost
dynamic range (though I have no way of knowing what dynamic range it had
before it started smoking), the left front channel power seems very low and
the DVD displays for a few minutes then the picture gets very choppy.

Does anyone know if any of this can be traced to whatever is powered when
the unit is in standby mode? Logic seems to dictate that the only thing
needed to be powered wjem in standby mode is the remote unit and that seems
to be working.

I have difficulty in believing that the left hand power transistors or the
servos to the DVD laser were powered when the smoke incident took place.

It does tout itself as a 1000 watt unit which seems to me more than a bit
like a very 1960s looking figure. The speakers are incredibly tinny looking
and the sub is made predominantly of particle board. The unit has no weight
to speak of to support any sort of power transformers supplying 1000 watt
transistors and heat sinking to them looks minimal. I suspect the impedance
is under an Ohm (and I have it connected to ordinary 8 ohm speakers at the
front)

(Yes, it IS made in China)

In article , "news.rcn.com" wrote:
This is an Insignia Model: IS-HTIB102732 progressive scan home theatre DVD
receiver. It was accidentally plugged it into a 220 volt source and
"clouds" of white smoke apparently started coming out of the left hand side
where the power supply is, even though the person who did it says it wasn't
actually turned on. (surely if it was unplugged, plugging it in would put
it into stand-by mode, - it wouldnt try to turn itself ON?)

The wall fuse blew about five seconds after it started smoking.

The unit does however now turn on! And it seems to work. And I cant see
any damage to the power supply area on the left of the unit! Curiously
there is what looks like a fuse on the power supply board which doesn't even
look blown?

The problems for which it has come to me are that it seems to have lost
dynamic range (though I have no way of knowing what dynamic range it had
before it started smoking), the left front channel power seems very low and
the DVD displays for a few minutes then the picture gets very choppy.

Does anyone know if any of this can be traced to whatever is powered when
the unit is in standby mode? Logic seems to dictate that the only thing
needed to be powered wjem in standby mode is the remote unit and that seems
to be working.

I have difficulty in believing that the left hand power transistors or the
servos to the DVD laser were powered when the smoke incident took place.

It does tout itself as a 1000 watt unit which seems to me more than a bit
like a very 1960s looking figure. The speakers are incredibly tinny looking
and the sub is made predominantly of particle board. The unit has no weight
to speak of to support any sort of power transformers supplying 1000 watt
transistors and heat sinking to them looks minimal. I suspect the impedance
is under an Ohm (and I have it connected to ordinary 8 ohm speakers at the
front)

(Yes, it IS made in China)


Subtract 2 zero's off of that and youd more likely have the correct wattage.

news.rcn.com wrote:
This is an Insignia Model: IS-HTIB102732 progressive scan home theatre DVD
receiver. It was accidentally plugged it into a 220 volt source and
"clouds" of white smoke apparently started coming out of the left hand side
where the power supply is, even though the person who did it says it wasn't
actually turned on. (surely if it was unplugged, plugging it in would put
it into stand-by mode, - it wouldnt try to turn itself ON?)

The wall fuse blew about five seconds after it started smoking.

The unit does however now turn on! And it seems to work. And I cant see
any damage to the power supply area on the left of the unit! Curiously
there is what looks like a fuse on the power supply board which doesn't even
look blown?

The problems for which it has come to me are that it seems to have lost
dynamic range (though I have no way of knowing what dynamic range it had
before it started smoking), the left front channel power seems very low and
the DVD displays for a few minutes then the picture gets very choppy.

Does anyone know if any of this can be traced to whatever is powered when
the unit is in standby mode? Logic seems to dictate that the only thing
needed to be powered wjem in standby mode is the remote unit and that seems
to be working.

I have difficulty in believing that the left hand power transistors or the
servos to the DVD laser were powered when the smoke incident took place.

It does tout itself as a 1000 watt unit which seems to me more than a bit
like a very 1960s looking figure. The speakers are incredibly tinny looking
and the sub is made predominantly of particle board. The unit has no weight
to speak of to support any sort of power transformers supplying 1000 watt
transistors and heat sinking to them looks minimal. I suspect the impedance
is under an Ohm (and I have it connected to ordinary 8 ohm speakers at the
front)

(Yes, it IS made in China)


Could there be an overvoltage protection (a MOV) be present
at the mains input? That one would blow a fuse, and the rest
might still be working.
That happend here when somebody put a computer from the USA
on 240 volts. He switched it to 240, but the MOVS were still
meant for 120 volts and kind of got smoked.

"news.rcn.com" wrote in message
...
This is an Insignia Model: IS-HTIB102732 progressive scan home theatre DVD
receiver. It was accidentally plugged it into a 220 volt source and
"clouds" of white smoke apparently started coming out of the left hand
side where the power supply is, even though the person who did it says it
wasn't actually turned on. (surely if it was unplugged, plugging it in
would put it into stand-by mode, - it wouldnt try to turn itself ON?)

The wall fuse blew about five seconds after it started smoking.

The unit does however now turn on! And it seems to work. And I cant see
any damage to the power supply area on the left of the unit! Curiously
there is what looks like a fuse on the power supply board which doesn't
even look blown?

The problems for which it has come to me are that it seems to have lost
dynamic range (though I have no way of knowing what dynamic range it had
before it started smoking), the left front channel power seems very low
and the DVD displays for a few minutes then the picture gets very choppy.

Does anyone know if any of this can be traced to whatever is powered when
the unit is in standby mode? Logic seems to dictate that the only thing
needed to be powered wjem in standby mode is the remote unit and that
seems to be working.

I have difficulty in believing that the left hand power transistors or the
servos to the DVD laser were powered when the smoke incident took place.

It does tout itself as a 1000 watt unit which seems to me more than a bit
like a very 1960s looking figure. The speakers are incredibly tinny
looking and the sub is made predominantly of particle board. The unit has
no weight to speak of to support any sort of power transformers supplying
1000 watt transistors and heat sinking to them looks minimal. I suspect
the impedance is under an Ohm (and I have it connected to ordinary 8 ohm
speakers at the front)

(Yes, it IS made in China)


The first thing to note is that any output power quoted on these Chinese HC
and hifi systems, is a total power, so with 6 channels of output, that takes
it down to 180 watts per channel before you start. The next thing to note is
that the power quoted is
back-pedalling-mid-winter-differential-peak-garage-music-with-a-following-wind
power, which is aproximately 50 times RMS output power, so 3.6 watts RMS
into 4 ohms per channel, is about what you can expect to get ...

As far as what exactly was powered when the excess voltage was applied, you
can by no means assume that it was only the standby supply. Many such items
will come fully or briefly fully to life, after power is reaplied from a
full power down. This allows the system control micro to do a status check
on the machine's current mechanical condition, and also allows the system to
check for such things as pending timer events, or to resume playing and so
on, after a power interuption, which may be due to an external power line
interuption, outside the user's control. Many units 'remember' whether they
were on, before the power was removed, for just this reason.

Further, if a switcher is hit with double the voltage it's expecting, then
after being very lucky that the side of the chopper transistor didn't zoom
off into space, there's no telling what unpredictable things that the power
supply may have done as a result.

There are not too many places that a "cloud of white smoke" can have come
from, without any obvious damage being visible. My best bet would be that it
came from the main filter cap. If the power supply is designed for 110v
operation, then the chances are that this cap is rated to only about 200v.
If 220v ac was applied to the unit, the voltage across this cap will have
been in excess of 300v. Release of the magic white smoke is the usual result
of doing this to an electrolytic.

Without any further messing about, the very first thing that I would do, is
to replace that cap. It could well be damaged, and be causing the supply to
suffer excess primary-side ripple. This in turn, can lead to erratic
operation, and excessive noise on the secondary rails, which may well result
in poor playability issues. I do, however, feel that lack of output on one
front channel compared to the other, is unlikely to be a power supply issue.
I would feel inclined to investigate this by putting a CD test disc with
audio tones on it, into the machine, and then comparing levels between
channels, with a 'scope. Is the value of the unit sufficient to warrant your
time getting into this to component level, though ... ?

Arfa

"Arfa Daily" wrote in message
...

"news.rcn.com" wrote in message
...
This is an Insignia Model: IS-HTIB102732 progressive scan home theatre
DVD receiver. It was accidentally plugged it into a 220 volt source and
"clouds" of white smoke apparently started coming out of the left hand
side where the power supply is, even though the person who did it says
it wasn't actually turned on. (surely if it was unplugged, plugging it
in would put it into stand-by mode, - it wouldnt try to turn itself ON?)

The wall fuse blew about five seconds after it started smoking.

The unit does however now turn on! And it seems to work. And I cant see
any damage to the power supply area on the left of the unit! Curiously
there is what looks like a fuse on the power supply board which doesn't
even look blown?

The problems for which it has come to me are that it seems to have lost
dynamic range (though I have no way of knowing what dynamic range it had
before it started smoking), the left front channel power seems very low
and the DVD displays for a few minutes then the picture gets very choppy.

Does anyone know if any of this can be traced to whatever is powered when
the unit is in standby mode? Logic seems to dictate that the only thing
needed to be powered wjem in standby mode is the remote unit and that
seems to be working.

I have difficulty in believing that the left hand power transistors or
the servos to the DVD laser were powered when the smoke incident took
place.

It does tout itself as a 1000 watt unit which seems to me more than a bit
like a very 1960s looking figure. The speakers are incredibly tinny
looking and the sub is made predominantly of particle board. The unit
has no weight to speak of to support any sort of power transformers
supplying 1000 watt transistors and heat sinking to them looks minimal.
I suspect the impedance is under an Ohm (and I have it connected to
ordinary 8 ohm speakers at the front)

(Yes, it IS made in China)


The first thing to note is that any output power quoted on these Chinese
HC and hifi systems, is a total power, so with 6 channels of output, that
takes it down to 180 watts per channel before you start. The next thing to
note is that the power quoted is
back-pedalling-mid-winter-differential-peak-garage-music-with-a-following-wind
power, which is aproximately 50 times RMS output power, so 3.6 watts RMS
into 4 ohms per channel, is about what you can expect to get ...

As far as what exactly was powered when the excess voltage was applied,
you can by no means assume that it was only the standby supply. Many such
items will come fully or briefly fully to life, after power is reaplied
from a full power down. This allows the system control micro to do a
status check on the machine's current mechanical condition, and also
allows the system to check for such things as pending timer events, or to
resume playing and so on, after a power interuption, which may be due to
an external power line interuption, outside the user's control. Many units
'remember' whether they were on, before the power was removed, for just
this reason.

Further, if a switcher is hit with double the voltage it's expecting, then
after being very lucky that the side of the chopper transistor didn't zoom
off into space, there's no telling what unpredictable things that the
power supply may have done as a result.

There are not too many places that a "cloud of white smoke" can have come
from, without any obvious damage being visible. My best bet would be that
it came from the main filter cap. If the power supply is designed for 110v
operation, then the chances are that this cap is rated to only about 200v.
If 220v ac was applied to the unit, the voltage across this cap will have
been in excess of 300v. Release of the magic white smoke is the usual
result of doing this to an electrolytic.

Without any further messing about, the very first thing that I would do,
is to replace that cap. It could well be damaged, and be causing the
supply to suffer excess primary-side ripple. This in turn, can lead to
erratic operation, and excessive noise on the secondary rails, which may
well result in poor playability issues. I do, however, feel that lack of
output on one front channel compared to the other, is unlikely to be a
power supply issue. I would feel inclined to investigate this by putting a
CD test disc with audio tones on it, into the machine, and then comparing
levels between channels, with a 'scope. Is the value of the unit
sufficient to warrant your time getting into this to component level,
though ... ?

Arfa
Thanks for the input guys: you have hit the nail right on the thumb with
this one as I wanted to know if anyone had any experience with these units
precisely because it is unlikely to be worth spending any money on it.
Yes, my reference to the power figures of the 1960s was indicative of what I
think this unit is capable of and what continuous RMS power means in
relation to the 1000W output quoted. Incidentally I had to play a trick to
get the sub to work 'properly'. There is only one channel output to the
sub, a positive wire and a ground wire. My sub which is 8 Ohms obviously
has two channels going into it. SO I connected both positives and both
grounds to each other (therefore in parallel) to connect the sub to the amp,
thinking that I am halving the impedance to 4 Ohms, which might well be more
in line with what the amp is expecting. If this induces anyone to clutch
stomachs laughing and fall off chairs etc, please post because the sub does
actually work and produce some slightly sybaritic sound.

I freely admit that I may ultimately have to connect a line level output to
an external amp however.

The test CD is a good idea if I can find one cheaply enough on eBay or
somewhere though the only scope I have is on a 1970s Marantz tuner (don't
laugh) and it doesn't have a time line. As I indicated, I am curious about
that left front channel not sounding correct and cant believe that the power
through some transformer to a power transistor could have been in any way
turned on when the unit is in standby mode.

I tried looking for the filter caps when I was inside the unit because when
I first saw the board looking fine, I thought that the white smoke was most
likely the oily insulation between the coiled up parts of some cap or other.
But as it is so cheaply made, they don't exactly look gigantic and all caps
inside the unit look vaguely similar. None of them look burned out or
'melted' unless there is some carbonisation on the underside of the board
which I cant see. But if there was, I doubt the unit would work. I am just
a bit surprised that with this level of cheapness in the power transistor
transformers and the level of money saving in the heat sinking, a unit which
had suffered such 'damage' could continue to work AND have no appreciable
symptoms. But I am intrigued by your reference to "excessive noise on the
secondary rails". There IS an excessive ringing on the front right channel
which might not be present on the left channel because the output is so
deficient in that part of the spectrum. As I say, I will probably
ultimately have to connect a line level output to an external amp

BTW on further enquiry, when the unit was plugged in, flashing lights
started looking as if they were 'blowing' all over the front panel (while it
was presumably clearing its memories etc). I am just a bit surprised that
no appreciable processors have blown. The unit IS very slow to respond to
the remote control however. But the owner says it was always a bit slow to
respond to commands like OPEN
TRAY etc.

Anyone got any ideas on the choppy video or is THAT indicative of some
processor being blown?

Arfa Daily wrote:
"news.rcn.com" wrote in message
...
This is an Insignia Model: IS-HTIB102732 progressive scan home theatre DVD
receiver. It was accidentally plugged it into a 220 volt source and
"clouds" of white smoke apparently started coming out of the left hand
side where the power supply is, even though the person who did it says it
wasn't actually turned on. (surely if it was unplugged, plugging it in
would put it into stand-by mode, - it wouldnt try to turn itself ON?)

The wall fuse blew about five seconds after it started smoking.

The unit does however now turn on! And it seems to work. And I cant see
any damage to the power supply area on the left of the unit! Curiously
there is what looks like a fuse on the power supply board which doesn't
even look blown?

The problems for which it has come to me are that it seems to have lost
dynamic range (though I have no way of knowing what dynamic range it had
before it started smoking), the left front channel power seems very low
and the DVD displays for a few minutes then the picture gets very choppy.

Does anyone know if any of this can be traced to whatever is powered when
the unit is in standby mode? Logic seems to dictate that the only thing
needed to be powered wjem in standby mode is the remote unit and that
seems to be working.

I have difficulty in believing that the left hand power transistors or the
servos to the DVD laser were powered when the smoke incident took place.

It does tout itself as a 1000 watt unit which seems to me more than a bit
like a very 1960s looking figure. The speakers are incredibly tinny
looking and the sub is made predominantly of particle board. The unit has
no weight to speak of to support any sort of power transformers supplying
1000 watt transistors and heat sinking to them looks minimal. I suspect
the impedance is under an Ohm (and I have it connected to ordinary 8 ohm
speakers at the front)

(Yes, it IS made in China)


The first thing to note is that any output power quoted on these Chinese HC
and hifi systems, is a total power, so with 6 channels of output, that takes
it down to 180 watts per channel before you start. The next thing to note is
that the power quoted is
back-pedalling-mid-winter-differential-peak-garage-music-with-a-following-wind
power, which is aproximately 50 times RMS output power, so 3.6 watts RMS
into 4 ohms per channel, is about what you can expect to get ...

As far as what exactly was powered when the excess voltage was applied, you
can by no means assume that it was only the standby supply. Many such items
will come fully or briefly fully to life, after power is reaplied from a
full power down. This allows the system control micro to do a status check
on the machine's current mechanical condition, and also allows the system to
check for such things as pending timer events, or to resume playing and so
on, after a power interuption, which may be due to an external power line
interuption, outside the user's control. Many units 'remember' whether they
were on, before the power was removed, for just this reason.

Further, if a switcher is hit with double the voltage it's expecting, then
after being very lucky that the side of the chopper transistor didn't zoom
off into space, there's no telling what unpredictable things that the power
supply may have done as a result.

There are not too many places that a "cloud of white smoke" can have come
from, without any obvious damage being visible. My best bet would be that it
came from the main filter cap. If the power supply is designed for 110v
operation, then the chances are that this cap is rated to only about 200v.
If 220v ac was applied to the unit, the voltage across this cap will have
been in excess of 300v. Release of the magic white smoke is the usual result
of doing this to an electrolytic.

Without any further messing about, the very first thing that I would do, is
to replace that cap. It could well be damaged, and be causing the supply to
suffer excess primary-side ripple. This in turn, can lead to erratic
operation, and excessive noise on the secondary rails, which may well result
in poor playability issues. I do, however, feel that lack of output on one
front channel compared to the other, is unlikely to be a power supply issue.
I would feel inclined to investigate this by putting a CD test disc with
audio tones on it, into the machine, and then comparing levels between
channels, with a 'scope. Is the value of the unit sufficient to warrant your
time getting into this to component level, though ... ?

Arfa


I love it...
"The first thing to note is that any output power quoted on these
Chinese HC
and hifi systems, is a total power, so with 6 channels of output, that
takes
it down to 180 watts per channel before you start. The next thing to
note is
that the power quoted is
back-pedalling-mid-winter-differential-peak-garage-music-with-a-following-wind

power, which is aproximately 50 times RMS output power, so 3.6 watts RMS
into 4 ohms per channel, is about what you can expect to get ..."

And that is exactly true. I've noticed that about 3-4 yrs ago and I
thought I was losing my hearing. My 20 yo Marantz 100 w/channel stereo
receiver coupled with my JBL studio speakers will rattle the windows at
2/3rds full volume. I've always wanted to do a power test on these
units but never had the time...I just assign them to the 'junk' catagory
and move on to real units...Too bad though, now the Chinese are
redefining a 'watt' to a milli-watt....sigh...wonder how the mfg are
allowed to get away with it. The equations for power, and the
conditions under which it is measured is (was?) pretty much a standard.
Hmmm, maybe the speakers are extremely inefficient?!?!? lol
-J