Hi,
I'm a total electronics newbie, so forgive the ignorance! I have just
gotten a device (a drum machine) with an apparently dirty DC input
power socket. Using a 9V AC-DC adapter, the unit works, but only when
the connector is just in the RIGHT position. Otherwise the thing
doesn't turn on. How does on go about cleaning out one of these jacks?
The jack is not loose or anything and fits the plug very tightly, but
the slightest movement can cut the power. Any suggestions?


Also, while I'm here, can any damage be done by using a 300 mA adapter
on equipment that requires only 50 mA? Again, total newbie here, but
using this adapter on the drum machine hasn't hurt it (yet!). Thanks
in advance.

wrote in message
ups.com...
Hi,
I'm a total electronics newbie, so forgive the ignorance! I have just
gotten a device (a drum machine) with an apparently dirty DC input
power socket. Using a 9V AC-DC adapter, the unit works, but only when
the connector is just in the RIGHT position. Otherwise the thing
doesn't turn on. How does on go about cleaning out one of these jacks?
The jack is not loose or anything and fits the plug very tightly, but
the slightest movement can cut the power. Any suggestions?


Also, while I'm here, can any damage be done by using a 300 mA adapter
on equipment that requires only 50 mA? Again, total newbie here, but
using this adapter on the drum machine hasn't hurt it (yet!). Thanks
in advance.

its more than likely its a either a broken joint on the PCB or cable

Howdy! No need to apologize for asking a question!. The most likely
suspects for your intermittent power with that AC-DC adapter are
that you may have an adapter plug (if coaxial) with a center female
that's too large OR that the coaxial type power jack (I'm assuming
that's what you have) has a poor "switched" contact inside it which is
also very common. Does this unit have provision for internal batteries?
As to your second request regarding the use of a power cube rated
apparently at the same voltage but higher current, the answer is
"maybe". The reason here is that many (most) of these adapters are
unregulated and are nominally rated for their voltage AT the rated
current - so using it on a light load will often result in a
significantly higher voltage (measure it to be sure under load.....using
a subsitute resistance instead of your valued load is the best way to
get a feeling for whether it'll be acceptable).

Gord

wrote:

Hi,
I'm a total electronics newbie, so forgive the ignorance! I have just
gotten a device (a drum machine) with an apparently dirty DC input
power socket. Using a 9V AC-DC adapter, the unit works, but only when
the connector is just in the RIGHT position. Otherwise the thing
doesn't turn on. How does on go about cleaning out one of these jacks?
The jack is not loose or anything and fits the plug very tightly, but
the slightest movement can cut the power. Any suggestions?


Also, while I'm here, can any damage be done by using a 300 mA adapter
on equipment that requires only 50 mA? Again, total newbie here, but
using this adapter on the drum machine hasn't hurt it (yet!). Thanks
in advance.

Hi,
thanks for the suggestions... I somehow doubt there's a connection
broken as I can't see it ever being able to break in the first place
i.e. the unit was never opened as far as I know. The too large center
female maybe the problem (and I am using a universal, rather than
device specific power supply), but looking at the jack, it is quite
dirty, so I wonder is there a way to clean it up easily? and if so,
would that help anything?

The device DOES use batteries, but these are also not working at the
moment. I cleaned up the blue gunk from the springs, but the negative
(-) contacts are brown and dirty as well, so I guess there's no
connection being made... I tried using an eraser to clean them, but to
no avail. I don't know how else to clean these contacts. Any other
suggestions?

Anonymouswrote:
Hi,
I'm a total electronics newbie, so forgive the ignorance! I have
just
gotten a device (a drum machine) with an apparently dirty DC input
power socket. Using a 9V AC-DC adapter, the unit works, but only
when
the connector is just in the RIGHT position. Otherwise the thing
doesn't turn on. How does on go about cleaning out one of these
jacks?
The jack is not loose or anything and fits the plug very tightly,
but
the slightest movement can cut the power. Any suggestions?


Also, while I'm here, can any damage be done by using a 300 mA
adapter
on equipment that requires only 50 mA? Again, total newbie here,
but
using this adapter on the drum machine hasn't hurt it (yet!).
Thanks
in advance.

I don`t think you have a dirty plugin jack. I beleave it may have some
bad solder connections where it is attached to the main powersupply
board or you may have a faulty 9 volt adaptor.

Anonymouswrote:
Hi,
thanks for the suggestions... I somehow doubt there's a connection
broken as I can't see it ever being able to break in the first
place
i.e. the unit was never opened as far as I know. The too large
center
female maybe the problem (and I am using a universal, rather than
device specific power supply), but looking at the jack, it is quite
dirty, so I wonder is there a way to clean it up easily? and if
so,
would that help anything?

The device DOES use batteries, but these are also not working at
the
moment. I cleaned up the blue gunk from the springs, but the
negative
(-) contacts are brown and dirty as well, so I guess there's no
connection being made... I tried using an eraser to clean them, but
to
no avail. I don't know how else to clean these contacts. Any
other
suggestions?

Doesn`t matter if the unit was open up before or not. These solder
connections can come loose just by plugging the adaptor in and out.
This is a very common problem for these units that has an addaptor.
Either it has bad solder which I tink it does or the whole jack is
bad and needs to be replaced completely. But I would suggest to have
it opened up even tho this will be the first time the unit has
everbeen opened up and have those solder connections checked.

Thanks again for all the suggestions....
I will definitely have a look at the soldering. I am also ordering a
unit specific power supply which is cheap enough to at least help rule
out using the wrong sized connector.

Howdy again.....Reason I mentioned batteries is that many devices that
use batteries along with a DC jack, often have the jack disconnect the
batteries when the adapter is plugged in OR use the adapter to charge a
NICAD pack with the device disconnected via the jack switched
contact......I've often found that switched contact to be poor quality
and a source of problems.

wrote:

Hi,
thanks for the suggestions... I somehow doubt there's a connection
broken as I can't see it ever being able to break in the first place
i.e. the unit was never opened as far as I know. The too large center
female maybe the problem (and I am using a universal, rather than
device specific power supply), but looking at the jack, it is quite
dirty, so I wonder is there a way to clean it up easily? and if so,
would that help anything?

The device DOES use batteries, but these are also not working at the
moment. I cleaned up the blue gunk from the springs, but the negative
(-) contacts are brown and dirty as well, so I guess there's no
connection being made... I tried using an eraser to clean them, but to
no avail. I don't know how else to clean these contacts. Any other
suggestions?

wrote:

Hi,
I'm a total electronics newbie, so forgive the ignorance! I have just
gotten a device (a drum machine) with an apparently dirty DC input
power socket. Using a 9V AC-DC adapter, the unit works, but only when
the connector is just in the RIGHT position. Otherwise the thing
doesn't turn on. How does on go about cleaning out one of these jacks?
The jack is not loose or anything and fits the plug very tightly, but
the slightest movement can cut the power. Any suggestions?


Also, while I'm here, can any damage be done by using a 300 mA adapter
on equipment that requires only 50 mA? Again, total newbie here, but
using this adapter on the drum machine hasn't hurt it (yet!). Thanks
in advance.

most likely a broken wire in the plug on the adapter or a inside
you have a solder joint connection problme! most likely needs to be
resoldered.


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