My SO accidentally used reverse polarity for the 6v dc power supply input
to the SuperScope PSD 230 portable CD player she just got secondhand.
She had not tried it before. Now it does not play with the power supply
only (tip positive, which I think is correct according to the diagram
on the outside of the box). However, it seems to play fine with batteries.

Does reversing the polarity of a 6v dc power supply to an electronic device
ordinarily fry the innards? Or is there usually some kind of protective
circuit that prevents this mistake from having serious consequences?

TIA...

some devices have a protection diode that may be now shorted or a small
fuse ot piece of the PWB is burned open

An electronics tech may be able to fix it.

Mark

z,

It sounds like a simple power circuit problem from what you described.
If you're located in the US, we will take a look at your player for
only a $25.00 fee, then if we can repair it, we'll only charge $15.00
to ship it back to you with insurance. We service this model and most
likely can have it back up and running for you in a few days. For more
info on our services, check our website:
http://www.techgadgetz.com/services.htm. If you wish to get more
information or have any questions, please email us at
. We look forward to assisting you!


--The all new Techgadgetz_dot_com

"z" wrote in message
m...
My SO accidentally used reverse polarity for the 6v dc power supply input
to the SuperScope PSD 230 portable CD player she just got secondhand.
She had not tried it before. Now it does not play with the power supply
only (tip positive, which I think is correct according to the diagram
on the outside of the box). However, it seems to play fine with
batteries.

Then it's most likely the tiny switch in the power socket which cuts off the
batteries.

Does reversing the polarity of a 6v dc power supply to an electronic
device
ordinarily fry the innards?

Usually not.

Or is there usually some kind of protective
circuit that prevents this mistake from having serious consequences?

Usually.
--
N

NSM,

Then it's most likely the tiny switch in the power socket which cuts
off the
batteries.

We disagree. Regular switches will carry current regardless of the
polarity. Most certainly the switch (if any installed) is fine and it's
something further inside the power circuit. Reversing of polarity on
the power supply WILL almost certainly fry the inside of a device, so
one must be careful when connecting the PS (I know as well, I have done
the same in my day). As for buying a new one, that's great if you can,
but from what I've seen, this model retails for a few hundred dollars.
Good luck


--Techgadgetz.com

"z" wrote in message
m...
My SO accidentally used reverse polarity for the 6v dc power supply input
to the SuperScope PSD 230 portable CD player she just got secondhand.
She had not tried it before. Now it does not play with the power supply
only (tip positive, which I think is correct according to the diagram
on the outside of the box). However, it seems to play fine with
batteries.

Does reversing the polarity of a 6v dc power supply to an electronic
device
ordinarily fry the innards? Or is there usually some kind of protective
circuit that prevents this mistake from having serious consequences?

TIA...



If it still works on batteries then you got very lucky and there's probably
a protection diode, look for a burned trace or micro fuse near the input
jack. Usually reverse polarity will fry the device instantly, not sure why
they don't all have a diode.

On Sat, 09 Apr 2005 03:38:08 GMT, "James Sweet"
put finger to keyboard and composed:


"z" wrote in message
om...
My SO accidentally used reverse polarity for the 6v dc power supply input
to the SuperScope PSD 230 portable CD player she just got secondhand.
She had not tried it before. Now it does not play with the power supply
only (tip positive, which I think is correct according to the diagram
on the outside of the box). However, it seems to play fine with
batteries.

Does reversing the polarity of a 6v dc power supply to an electronic
device
ordinarily fry the innards? Or is there usually some kind of protective
circuit that prevents this mistake from having serious consequences?

TIA...



If it still works on batteries then you got very lucky and there's probably
a protection diode, look for a burned trace or micro fuse near the input
jack. Usually reverse polarity will fry the device instantly, not sure why
they don't all have a diode.

A friend in the industry calls this a "dickhead diode". On quite a few
occasions I've added such diodes to protect myself from bounced jobs.
For some low power devices with a high enough supply margin you can
safely add a diode in series with the supply.


- Franc Zabkar
--
Please remove one 's' from my address when replying by email.

In article .com,
wrote:
We disagree. Regular switches will carry current regardless of the
polarity. Most certainly the switch (if any installed) is fine and it's
something further inside the power circuit. Reversing of polarity on
the power supply WILL almost certainly fry the inside of a device, so
one must be careful when connecting the PS (I know as well, I have done
the same in my day). As for buying a new one, that's great if you can,
but from what I've seen, this model retails for a few hundred dollars.
Good luck

It only needs one diode to protect against wrong connection, and many
things that take disposable batteries are fitted with protection since
it's all too easy to fit those incorrectly. Under those circumstances it
would be likely that diode would protect from wrong connection of the PS
too.

Many of these devices use a SMPS to give a constant supply regardless of
battery voltage etc, and that too *should* incorporate reversal protection.

But then 'they' do tend to save on tiny costs wherever possible...

--
*Beauty is in the eye of the beer holder...

Dave Plowman London SW
To e-mail, change noise into sound.

On Sat, 09 Apr 2005 17:55:28 +1000, Franc Zabkar
wrote:


A friend in the industry calls this a "dickhead diode".

been there done that. certified dickhead. replaced the diode, unit
worked fine.

Or they can just go to a store and get a new one for $40.
wrote in message
ups.com...
z,

It sounds like a simple power circuit problem from what you described.
If you're located in the US, we will take a look at your player for
only a $25.00 fee, then if we can repair it, we'll only charge $15.00
to ship it back to you with insurance. We service this model and most
likely can have it back up and running for you in a few days. For more
info on our services, check our website:
http://www.techgadgetz.com/services.htm. If you wish to get more
information or have any questions, please email us at
. We look forward to assisting you!


--The all new Techgadgetz_dot_com

wrote in message
oups.com...
NSM,

Then it's most likely the tiny switch in the power socket which cuts
off the
batteries.

We disagree. Regular switches will carry current regardless of the
polarity. ...

If she plugged in reverse power she may have used an oversized plug. If it's
OK on batteries the fault is in a tiny section of the circuit, and 99% of
the time it's that switch. They don't BURN out, they get bent out of shape.
--
N