Cordless phone doesn't beep when put to charge

[Hank]

Hello

I have a Sanyo 900MHz cordless phone (model CLT-9922). In recent
weeks, when I put it on the base unit to charge, I don't hear a *beep*
sound which confirms that charging is taking place. However, the LED
on the base unit does light up as if to indicate the phone was
actually charging. But I know no charging is taking place after
finding the phone dead after leaving it on the base unit for a couple
of days. The phone is just over a year old so the warranty is over.

The funny thing is, if you keep trying to put the phone on the base
unit, after the 20th time you may actually hear a *beep* and the phone
will charge.

What could be the cause of this behaviour?

Thanks in advance
H

 

[Anthony Fremont]

The funny thing is, if you keep trying to put the phone on the base
unit, after the 20th time you may actually hear a *beep* and the phone
will charge.

What could be the cause of this behaviour?

Dirty contacts. Regardless of how they look, take an eraser and clean
them. For some reason, there are a bunch of devices that behave like
this. I believe it has something to do with dissimilar metals used in
the contacts building up oxides.

 

[Ken Weitzel]

Hello

I have a Sanyo 900MHz cordless phone (model CLT-9922). In recent
weeks, when I put it on the base unit to charge, I don't hear a *beep*
sound which confirms that charging is taking place. However, the LED
on the base unit does light up as if to indicate the phone was
actually charging. But I know no charging is taking place after
finding the phone dead after leaving it on the base unit for a couple
of days. The phone is just over a year old so the warranty is over.

The funny thing is, if you keep trying to put the phone on the base
unit, after the 20th time you may actually hear a *beep* and the phone
will charge.

What could be the cause of this behaviour?

Thanks in advance
H

Hi...

Get a hold of a new pencil, or one that at least has
a new-ish clean unused eraser.

Use the eraser to gently scrub the contacts on both the
phone and charger until they're clean looking and shiny.

Ken

 

[Terry]

Dirty contacts. Regardless of how they look, take an eraser and clean
them. For some reason, there are a bunch of devices that behave like
this. I believe it has something to do with dissimilar metals used in
the contacts building up oxides.

Excellent suggestion. And/or maybe wipe off any grease with a bit of that
car lock de-icer alcohol?

Our GE 900 cordless did the same sort of thing.
After we mislaid handset for about a week.
When found, handset battery which was supposedly OK since it had been
replaced a few months ago, was completely flat.
It has taken at least a week and a half for the battery recharge. Now normal
So could be a bad cell/s?

In reference to dissimilar metals/oxidation etc. causing 'dirty contacts', a
common fault back designation in the days of relays! Especially if you
didn't REALLY KNOW what the problems was! You had to write something in the
trouble log ; see also 'contact wetting'.

'Contact wetting' was/is the recommended practice of having a few microamps
flow through an electrical contact that was not otherwise carrying any DC
current (voice circuit relay contact, audio jack etc.) offset contact
oxidation. Not possible of course with the contacts of a tel. handset that
is detached from the base.

 

[Anthony Fremont]

Excellent suggestion. And/or maybe wipe off any grease with a bit of that
car lock de-icer alcohol?

Our GE 900 cordless did the same sort of thing.
After we mislaid handset for about a week.
When found, handset battery which was supposedly OK since it had been
replaced a few months ago, was completely flat.
It has taken at least a week and a half for the battery recharge. Now normal
So could be a bad cell/s?

Maybe you had a cell get reverse polarized from it running so low, but
I'd suspect that wouldn't correct itself. Perhaps also the contacts are
a bit high resistance so it took allot longer to charge. It's funny, I
have an old phone (~10years) that never had any trouble with the
contacts, no matter what. I now have a cheapy that often has issues
with not wanting to charge until I clean up the contacts, go figure. It
must be something to do with the type of metal(s).

In reference to dissimilar metals/oxidation etc. causing 'dirty contacts', a
common fault back designation in the days of relays! Especially if you
didn't REALLY KNOW what the problems was! You had to write something in the
trouble log ; see also 'contact wetting'.

'Contact wetting' was/is the recommended practice of having a few microamps
flow through an electrical contact that was not otherwise carrying any DC
current (voice circuit relay contact, audio jack etc.) offset contact
oxidation. Not possible of course with the contacts of a tel. handset that
is detached from the base.

I think this is still commonly done when miniscule amounts of current
are involved (like line-level audio) and plugs/jacks are being used. I
believe it's also done with potentiometers to insure that they conduct
the signal.

 

[rb]

Forget all the cleaning the contacts.
Replace the batteries..............