The 12 V DC power polarity to a flatscreen TV was unfortunately reversed

The TV does not now function and I would like to know if anything can
be done to repair it or is all lost

Thanks

Mike
--

On Mon, 16 Jul 2007 21:37:13 -0000, Nowhere wrote:
The 12 V DC power polarity to a flatscreen TV was unfortunately reversed
The TV does not now function and I would like to know if anything can
be done to repair it or is all lost

Someone will get back to you just as soon as the crack
sci.electronics.repair mind-reading team gives the make and model number
to the crack sci.electronics.repair diagnosis team.

Spam Trap wrote:

On Mon, 16 Jul 2007 21:37:13 -0000, Nowhere wrote:
The 12 V DC power polarity to a flatscreen TV was unfortunately
reversed The TV does not now function and I would like to know if
anything can be done to repair it or is all lost

Someone will get back to you just as soon as the crack
sci.electronics.repair mind-reading team gives the make and model
number to the crack sci.electronics.repair diagnosis team.



Ok Its a Bush LCD 15DVD008

Thanks

--

"Meat Plow" wrote in message
...
On Mon, 16 Jul 2007 21:37:13 +0000, Nowhere wrote:

The 12 V DC power polarity to a flatscreen TV was unfortunately reversed

The TV does not now function and I would like to know if anything can
be done to repair it or is all lost

Thanks


How in the bloody hell do you reverse the polarity on that? Did it not
come with plugs and adapters that prevent such lunacy?
You may luck out with an internal polarity protection device and a
fuseable something or other or you may have done greater, more costly
damage.


Did the original power supply burn up, and you just found this one with the
right plug on, and assumed it would be right, by any chance ? I've seen it
happen a couple of times. Most of those Bush models have a polarity
protection diode right across the power socket, and it fails short circuit.

Arfa

"Nowhere" wrote in message
...
The 12 V DC power polarity to a flatscreen TV was unfortunately reversed

The TV does not now function and I would like to know if anything can
be done to repair it or is all lost

Thanks

Mike
--


It could be a very simple fix, or it could be completely junked, but unless
you have some electronics knowledge there isn't anything you can do
yourself. Best suggestion I can give is take it to a shop and get it looked
at.

On Jul 16, 5:20 pm, "Nowhere" wrote:
Spam Trap wrote:
On Mon, 16 Jul 2007 21:37:13 -0000, Nowhere wrote:
The 12 V DC power polarity to a flatscreen TV was unfortunately
reversed The TV does not now function and I would like to know if
anything can be done to repair it or is all lost

Someone will get back to you just as soon as the crack
sci.electronics.repair mind-reading team gives the make and model
number to the crack sci.electronics.repair diagnosis team.

Ok Its a Bush LCD 15DVD008

Thanks

--

Do you have any electronics experience, such as with a multimeter or
oscilloscope?

H. R.(Bob) Hofmann

"Nowhere" wrote in message
...
The 12 V DC power polarity to a flatscreen TV was unfortunately reversed

The TV does not now function and I would like to know if anything can
be done to repair it or is all lost

There are basically 2 possibilities:

(1) Maybe it blew a fuse and/or a few components in the power supply and
nothing else.

(2) Or maybe all is lost.

Depends on the power supply circuitry.

How in the bloody hell do you reverse the polarity on that? Did it
not come with plugs and adapters that prevent such lunacy?
You may luck out with an internal polarity protection device and a
fuseable something or other or you may have done greater, more
costly damage.


Did the original power supply burn up, and you just found this one
with the right plug on, and assumed it would be right, by any chance
? I've seen it happen a couple of times. Most of those Bush models
have a polarity protection diode right across the power socket, and
it fails short circuit.

Arfa


No excuses it was a cock up of great magnitude I was trying an
alternative adaptor which had been cobbled together with an uncertain
polarity (unknown to me). My instincts were warning me but I had been
told that it should not damage the TV Serves me right I suppose

Normally I am quite handy and sensible with this type of work having
built 3 computers over the years. If I know what to look for and test I
could give it a go Just wasn't sure it was salvageable

Are there any technical specs anyahere I could check

Thanks

Mike

"Nowhere" wrote in message
...

How in the bloody hell do you reverse the polarity on that? Did it
not come with plugs and adapters that prevent such lunacy?
You may luck out with an internal polarity protection device and a
fuseable something or other or you may have done greater, more
costly damage.


Did the original power supply burn up, and you just found this one
with the right plug on, and assumed it would be right, by any chance
? I've seen it happen a couple of times. Most of those Bush models
have a polarity protection diode right across the power socket, and
it fails short circuit.

Arfa


No excuses it was a cock up of great magnitude I was trying an
alternative adaptor which had been cobbled together with an uncertain
polarity (unknown to me). My instincts were warning me but I had been
told that it should not damage the TV Serves me right I suppose

Normally I am quite handy and sensible with this type of work having
built 3 computers over the years. If I know what to look for and test I
could give it a go Just wasn't sure it was salvageable

Are there any technical specs anyahere I could check

Thanks

Mike

Look for a shorted diode near the input jack as others have recommended. If
you are handy with a soldering iron and a DMM you might get lucky and be
able to easily fix this.

Look for a shorted diode near the input jack as others have
recommended. If you are handy with a soldering iron and a DMM you
might get lucky and be able to easily fix this.


So far so good

Got the back off and think I have identified the diode Right next to
the DC input around 7mm long in glass/plastic The two leads in are
colored red. It could well be blown but very difficult to see

If I get a multimeter and plug the adaptor in and check I could verify
a this I suppose

If I want to replace it where would I get another from and what would I
need to look for (Spec etc)

Thanks

Mike




--

"Nowhere" wrote in message
...

Look for a shorted diode near the input jack as others have
recommended. If you are handy with a soldering iron and a DMM you
might get lucky and be able to easily fix this.


So far so good

Got the back off and think I have identified the diode Right next to
the DC input around 7mm long in glass/plastic The two leads in are
colored red. It could well be blown but very difficult to see

If I get a multimeter and plug the adaptor in and check I could verify
a this I suppose

If I want to replace it where would I get another from and what would I
need to look for (Spec etc)

Thanks

Mike

It's been a while since I did one, but as far as I can recall, the diode is
a pretty 'standard' looking thing, about 5-7mm long, coupla mm or so on the
diameter, black plastic, white or silver band one end. I seem to recall it
being pretty obvious, near to the input socket, but that's to the
experienced eye. To check it, you don't want to be having the PSU connected
again. You need a normal multimeter, set to its ohms range. If it's an
alalogue one, and the needle goes right over when you hook it across the
diode, both ways, or same test with a digital, reading is close to 0.00
ohms, then you can be reasonably sure that the diode is short circuit. You
can further confirm this, if you like, by then snipping one end lead, and
measuring again, directly across the diode, between the intact lead, and the
lead stump left on the diode. If you still get a short circuit reading, then
with the diode still snipped, you can try applying power again, making VERY
DEFINITELY SURE that you have the polarity correct. All being well, the set
will come back up, and you will be able to verify that there is no
additional damage. If all is ok, remove the power again, and go ahead and
replace the diode. Type is not critical - any from the 1N400x series for
example, but make sure that you fit it the right way round.

Arfa

It's been a while since I did one, but as far as I can recall, the
diode is a pretty 'standard' looking thing, about 5-7mm long, coupla
mm or so on the diameter, black plastic, white or silver band one
end. I seem to recall it being pretty obvious, near to the input
socket, but that's to the experienced eye.


Its the same size but is clear plastic with the leads colored red as
they enter the plastic Cant see any bands in silver or black I could
email you a photo if you wish then I can be sure it is the same thing

Mike

"Nowhere" wrote in message
...

It's been a while since I did one, but as far as I can recall, the
diode is a pretty 'standard' looking thing, about 5-7mm long, coupla
mm or so on the diameter, black plastic, white or silver band one
end. I seem to recall it being pretty obvious, near to the input
socket, but that's to the experienced eye.


Its the same size but is clear plastic with the leads colored red as
they enter the plastic Cant see any bands in silver or black I could
email you a photo if you wish then I can be sure it is the same thing

Mike

I don't think that this sounds like what we are looking for. By all means
e-mail me a photo if you like, and one of the whole lower part of the board
as well. If you do them in a reasonably high res and Jpeg or PDF them, I
should be able to zoom up on them pretty well to see if I can remember where
the diode was, and spot it. BB connection here, so no issue with size up to
mailbox capacity - say 8 meg to allow for other stuff that might be in
there.

Arfa