Mate's Dell Laptop (oldish) has flat batt and won;t boot.

Plug in to mains charger - won;t charge - batt light on lappy "winks"
once per insertion of the jack, then nought.

Lappy won't boot either when plugged in to the charger...?

Had batt out & makes no difference except the batt light "wink"
disappears when you shove the jack in.

Got charger here now, plugged in, green LED on tranny box is lit,
multimeter on the DC jack end - measuring 0.01V - it's rated on the
tranny label at 19.5v 3.3A....

Seems something not right - but :-

do laptop chargers "sense" and adjust their output somehow?? meaning I
can't actually say 100% it's the charger that's shagged & just acquire
a new one...?

All help appreciated

Cheers
Jim K

On Jul 2, 12:39*pm, Jim K wrote:


do laptop chargers "sense" and adjust their output somehow?? meaning I
can't actually say 100% it's the charger that's shagged & just acquire
a new one...?

All help appreciated

Cheers
Jim K

All the "chargers" I've seen are just switch mode power supplies.
Indeed, the generic replacements (rather than branded) ones make very
good power supplies for other uses. Shouldn't cost mor ethan £20 for a
new one.

The charging intelligence is in the laptop and/or battery.

MBQ

On Jul 2, 12:53 pm, "Man at B&Q" wrote:
On Jul 2, 12:39 pm, Jim K wrote:



do laptop chargers "sense" and adjust their output somehow?? meaning I
can't actually say 100% it's the charger that's shagged & just acquire
a new one...?

All help appreciated

Cheers
Jim K

All the "chargers" I've seen are just switch mode power supplies.
Indeed, the generic replacements (rather than branded) ones make very
good power supplies for other uses. Shouldn't cost mor ethan £20 for a
new one.

The charging intelligence is in the laptop and/or battery.

MBQ

Righto.

So I chopped the jack of the end to reveal a 3 core cable (which
surprised me a bit - was expecting 2)

There's an outer screen of decent multistrand (1) , then inside that
another smaller screen (2) & a core (3)

Now I can indeed get 19.5 from the bare end from the tranny -across 1
& 2
When I test across from 3 to 2 - i get 12.5v...

On the jack plug end (now removed and opened up to check) there are
indeed 3 connections - Outer screen (1) to outside of jackplug, inner
screen (2) to (appears to be) the inner surface of the jackplug ??, &
Central core (3) to centre pin.

Is this making any sense to anyone?

Cheers
Jim K

On 02/07/2012 12:39, Jim K wrote:
Mate's Dell Laptop (oldish) has flat batt and won;t boot.

Plug in to mains charger - won;t charge - batt light on lappy "winks"
once per insertion of the jack, then nought.

Lappy won't boot either when plugged in to the charger...?

Had batt out & makes no difference except the batt light "wink"
disappears when you shove the jack in.

Got charger here now, plugged in, green LED on tranny box is lit,
multimeter on the DC jack end - measuring 0.01V - it's rated on the
tranny label at 19.5v 3.3A....

These days they are almost always switched mode PSUs.

Seems something not right - but :-

do laptop chargers "sense" and adjust their output somehow?? meaning I
can't actually say 100% it's the charger that's shagged & just acquire
a new one...?

All help appreciated

They can and do vary. Some will always provide nominal voltage at the
plug even under no load and others require a certain minimum load and no
short circuits before they will drive the output high.

A sort of self protection against being left unplugged on an office desk
full of loose paperclips and staples.

A 22R 10W resistor (80p from Maplins seriously overrun so getting hot
quickly) or sacrificial automotive 12v lamp in series with multimeter on
the 10A range should give you a quick go/no-go indication.

--
Regards,
Martin Brown

On Monday, July 2, 2012 12:39:06 PM UTC+1, Jim K wrote:
Mate's Dell Laptop (oldish) has flat batt and won;t boot.

Plug in to mains charger - won;t charge - batt light on lappy "winks"
once per insertion of the jack, then nought.

Lappy won't boot either when plugged in to the charger...?

Had batt out & makes no difference except the batt light "wink"
disappears when you shove the jack in.

Got charger here now, plugged in, green LED on tranny box is lit,
multimeter on the DC jack end - measuring 0.01V - it's rated on the
tranny label at 19.5v 3.3A....

Seems something not right - but :-

do laptop chargers "sense" and adjust their output somehow?? meaning I
can't actually say 100% it's the charger that's shagged & just acquire
a new one...?

All help appreciated

Cheers
Jim K

I've heard that Apple batteries can sense when they are 'dead' and won't charge. If the Dell battery is behaving the same then maybe the battery is dead and has set itself not to be chargable, or it could be a cell or two is damged and that's why it won;t charge.
Is there anything else you could connect to the charge that's about 20V maybe 2 X 12V bulbs in series see if you can get any current out of the charger.

On 02/07/2012 13:48, whisky-dave wrote:
On Monday, July 2, 2012 12:39:06 PM UTC+1, Jim K wrote:
Mate's Dell Laptop (oldish) has flat batt and won;t boot.

Plug in to mains charger - won;t charge - batt light on lappy "winks"
once per insertion of the jack, then nought.

Lappy won't boot either when plugged in to the charger...?

Had batt out & makes no difference except the batt light "wink"
disappears when you shove the jack in.

Got charger here now, plugged in, green LED on tranny box is lit,
multimeter on the DC jack end - measuring 0.01V - it's rated on the
tranny label at 19.5v 3.3A....

Seems something not right - but :-

do laptop chargers "sense" and adjust their output somehow?? meaning I
can't actually say 100% it's the charger that's shagged & just acquire
a new one...?

All help appreciated

Cheers
Jim K

I've heard that Apple batteries can sense when they are 'dead' and won't charge. If the Dell battery is behaving the same then maybe the battery is dead and has set itself not to be chargable, or it could be a cell or two is damged and that's why it won;t charge.
Is there anything else you could connect to the charge that's about 20V maybe 2 X 12V bulbs in series see if you can get any current out of the charger.

All lithium-ion batteries should have a self protection suicide circuit
in them. They tend to catch fire spectacularly otherwise if they fail
short circuit a thermal runaway becomes inevitable. Not nice.

http://www.electronicsweekly.com/blo...mion-ba-1.html

ISTR Sony and Nokia had a bit of bother with it not all that long ago.

--
Regards,
Martin Brown

On Jul 2, 1:40 pm, Jim K wrote:
On Jul 2, 12:53 pm, "Man at B&Q" wrote:



On Jul 2, 12:39 pm, Jim K wrote:

do laptop chargers "sense" and adjust their output somehow?? meaning I
can't actually say 100% it's the charger that's shagged & just acquire
a new one...?

All help appreciated

Cheers
Jim K

All the "chargers" I've seen are just switch mode power supplies.
Indeed, the generic replacements (rather than branded) ones make very
good power supplies for other uses. Shouldn't cost mor ethan £20 for a
new one.

The charging intelligence is in the laptop and/or battery.

MBQ

Righto.

So I chopped the jack of the end to reveal a 3 core cable (which
surprised me a bit - was expecting 2)

There's an outer screen of decent multistrand (1) , then inside that
another smaller screen (2) & a core (3)

Now I can indeed get 19.5 from the bare end from the tranny -across 1
& 2
When I test across from 3 to 2 - i get 12.5v...

On the jack plug end (now removed and opened up to check) there are
indeed 3 connections - Outer screen (1) to outside of jackplug, inner
screen (2) to (appears to be) the inner surface of the jackplug ??, &
Central core (3) to centre pin.

Is this making any sense to anyone?

Cheers
Jim K

now bodged back together - but I reckon it's still same as b4.

Haven't got the lappy here so can't check...

Has anyone got a Dell PA12 charger/power lead and would kindly run a
meter over the jack plug end for me to see if this one is shagged or
not?

to recap this one gives
a) 19.5v between the inner and outer surfaces of the cylindrical bit
of the jack plug
b) 12 ish V between inner surface of the cylinderical bit and the
central pin
c) when off i get 6k ohm resistance across b)'s which I think works
out as a voltage dropper 19.5v to 12v that I see in b)

Cheers
Jim K

On Mon, 02 Jul 2012 04:39:06 -0700, Jim K wrote:
Got charger here now, plugged in, green LED on tranny box is lit,
multimeter on the DC jack end - measuring 0.01V - it's rated on the
tranny label at 19.5v 3.3A....

Seems something not right - but :-

do laptop chargers "sense" and adjust their output somehow?? meaning I
can't actually say 100% it's the charger that's shagged & just acquire a
new one...?

The one for my Dell throws out 19V even when it's not connected to the
laptop.

It might be a broken cable on the PSU's output, without any obvious
damage to the outside of the cable. BTDT. Most likely to happen either
right where the cable exits the PSU, or where it disappears into the
power jack which plugs into the back of the laptop.

If you've got nothing to lose, chop the cable a few inches* from the end
and check there for voltage; if it's OK, find another power connector
(e.g. possible donor from junk shop PSU) and splice/solder the cables
together (use some heatshrink if you want it to last, use electrical tape
if you want it to fall apart within a year ;-)

* and if that doesn't work, you can try opening the PSU, but they're
usually complete sods to get open, plus you'll have to bodge some way of
sealing them again once you've fixed he fault.

cheers

Jules

On Jul 2, 3:54 pm, Jules Richardson
wrote:
On Mon, 02 Jul 2012 04:39:06 -0700, Jim K wrote:
Got charger here now, plugged in, green LED on tranny box is lit,
multimeter on the DC jack end - measuring 0.01V - it's rated on the
tranny label at 19.5v 3.3A....

Seems something not right - but :-

do laptop chargers "sense" and adjust their output somehow?? meaning I
can't actually say 100% it's the charger that's shagged & just acquire a
new one...?

The one for my Dell throws out 19V even when it's not connected to the
laptop.

It might be a broken cable on the PSU's output, without any obvious
damage to the outside of the cable. BTDT. Most likely to happen either
right where the cable exits the PSU, or where it disappears into the
power jack which plugs into the back of the laptop.

If you've got nothing to lose, chop the cable a few inches* from the end
and check there for voltage; if it's OK, find another power connector
(e.g. possible donor from junk shop PSU) and splice/solder the cables
together (use some heatshrink if you want it to last, use electrical tape
if you want it to fall apart within a year ;-)

* and if that doesn't work, you can try opening the PSU, but they're
usually complete sods to get open, plus you'll have to bodge some way of
sealing them again once you've fixed he fault.

cheers

Jules

thanks for that. I googled a lot and actually found a thread from some
guy who's mended 100s of PA10s and PA12s.

Following his assessment guide I am pretty sure it is a short on the
DC side but ICBA to fix as a whole new chinesey on ebay is £6 posted
(from UK allegedly) or a 2nd hand genuine is abt £10 posted.

Just a new DC wire would be over £5 plus all faff & agro to fit and
scabby appearance of opened clamshell (yes they are a sod to open ;))

I've binned it and fingers crossed a "new" one will sort the issue.

Cheers all
Jim K

On 02/07/2012 13:40, Jim K wrote:


So I chopped the jack of the end to reveal a 3 core cable (which
surprised me a bit - was expecting 2)

Genuine Dell power adaptors have an ID chip (One-Wire Dallas thing) that
communicates and is recognized by the laptop on boot. Without that chip
(or a broken wire) the laptop disallows battery charging, but it should
at least run OK from the supply, on two wires.

A replacement Dell supply from CPC is less than £20. Or take your chance
on eBay between the real, compatible and the fake.

What model adaptor? laptop model?

--
Adrian C

On Jul 2, 4:14 pm, Adrian C wrote:
On 02/07/2012 13:40, Jim K wrote:



So I chopped the jack of the end to reveal a 3 core cable (which
surprised me a bit - was expecting 2)

Genuine Dell power adaptors have an ID chip (One-Wire Dallas thing) that
communicates and is recognized by the laptop on boot. Without that chip
(or a broken wire) the laptop disallows battery charging, but it should
at least run OK from the supply, on two wires.

MMM this one don't ;)

as detailed above I think it's a short in the DC lead and as cheap to
replace as mend so crossing 'em for that

A replacement Dell supply from CPC is less than £20. Or take your chance
on eBay between the real, compatible and the fake.

What model adaptor? laptop model?


PA12 adaptor
no laptop here at mo....

Jim K

On 02/07/2012 14:39, Jim K wrote:
On Jul 2, 1:40 pm, Jim wrote:
On Jul 2, 12:53 pm, "Man at wrote:



On Jul 2, 12:39 pm, Jim wrote:

do laptop chargers "sense" and adjust their output somehow?? meaning I
can't actually say 100% it's the charger that's shagged& just acquire
a new one...?

All help appreciated

Cheers
Jim K

All the "chargers" I've seen are just switch mode power supplies.
Indeed, the generic replacements (rather than branded) ones make very
good power supplies for other uses. Shouldn't cost mor ethan £20 for a
new one.

The charging intelligence is in the laptop and/or battery.

MBQ

Righto.

So I chopped the jack of the end to reveal a 3 core cable (which
surprised me a bit - was expecting 2)

There's an outer screen of decent multistrand (1) , then inside that
another smaller screen (2)& a core (3)

Now I can indeed get 19.5 from the bare end from the tranny -across 1
& 2
When I test across from 3 to 2 - i get 12.5v...

On the jack plug end (now removed and opened up to check) there are
indeed 3 connections - Outer screen (1) to outside of jackplug, inner
screen (2) to (appears to be) the inner surface of the jackplug ??,&
Central core (3) to centre pin.

Is this making any sense to anyone?

Cheers
Jim K

now bodged back together - but I reckon it's still same as b4.

Haven't got the lappy here so can't check...

If it's a Dell, the third core is used by the laptop to check for a
genuine Dell power supply, and if it isn't there or has the wrong
voltage on it, the battery won't charge. You get the same symptoms if
the third core is broken or the connector on the PCB is dodgy, say, due
to a dodgy joint.

It's their way of locking you in to buying genuine parts only. :-/


--
Tciao for Now!

John.

On Jul 2, 4:14 pm, Adrian C wrote:

On 02/07/2012 13:40, Jim K wrote:

So I chopped the jack of the end to reveal a 3 core cable (which
surprised me a bit - was expecting 2)

Genuine Dell power adaptors have an ID chip (One-Wire Dallas thing)
that
communicates and is recognized by the laptop on boot. Without that
chip
(or a broken wire) the laptop disallows battery charging, but it
should
at least run OK from the supply, on two wires.


MMM this one don't ;(( any thoughts as to why if it *isn't* the
charger?


A replacement Dell supply from CPC is less than £20. Or take your
chance
on eBay between the real, compatible and the fake.

What model adaptor? laptop model?

PA12 adaptor
no laptop here at mo....

I looked on CPC - how do you know they are Dell?

they look like same chinesey clones on ebay...

Jim K

On 02/07/12 12:39, Jim K wrote:
Mate's Dell Laptop (oldish) has flat batt and won;t boot.

Plug in to mains charger - won;t charge - batt light on lappy "winks"
once per insertion of the jack, then nought.

A possible cause is a broken connection between the laptop's power
socket and the motherboard. Try jiggling the connector about and see
whether the power light winks at you.

Another possible fault is a short-circuit causing the power supply to
shut down as soon as you plug it in.

Power input sockets are a weak-point in laptop construction. A component
costing pennies can stop the whole machine from working. And when
someone trips over the power cable the tug is transmitted to the socket.


--
Bernard Peek

On Jul 2, 6:42 pm, John Williamson
wrote:
On 02/07/2012 14:39, Jim K wrote:

On Jul 2, 1:40 pm, Jim wrote:
On Jul 2, 12:53 pm, "Man at wrote:

On Jul 2, 12:39 pm, Jim wrote:

do laptop chargers "sense" and adjust their output somehow?? meaning I
can't actually say 100% it's the charger that's shagged& just acquire
a new one...?

All help appreciated

Cheers
Jim K

All the "chargers" I've seen are just switch mode power supplies.
Indeed, the generic replacements (rather than branded) ones make very
good power supplies for other uses. Shouldn't cost mor ethan £20 for a
new one.

The charging intelligence is in the laptop and/or battery.

MBQ

Righto.

So I chopped the jack of the end to reveal a 3 core cable (which
surprised me a bit - was expecting 2)

There's an outer screen of decent multistrand (1) , then inside that
another smaller screen (2)& a core (3)

Now I can indeed get 19.5 from the bare end from the tranny -across 1
& 2
When I test across from 3 to 2 - i get 12.5v...

On the jack plug end (now removed and opened up to check) there are
indeed 3 connections - Outer screen (1) to outside of jackplug, inner
screen (2) to (appears to be) the inner surface of the jackplug ??,&
Central core (3) to centre pin.

Is this making any sense to anyone?

Cheers
Jim K

now bodged back together - but I reckon it's still same as b4.

Haven't got the lappy here so can't check...

If it's a Dell, the third core is used by the laptop to check for a
genuine Dell power supply, and if it isn't there or has the wrong
voltage on it, the battery won't charge. You get the same symptoms if
the third core is broken or the connector on the PCB is dodgy, say, due
to a dodgy joint.

mmm that's sounding more and more likely if it's not the adaptor - the
central pin measured 12v and (when powered "off") 6k ohms, between the
19.5 on the inside of the barrel bit of the jack, and the central data
pin.

If someone could kindly check their PA12 power supply with a meter I
could "know" if it's the adaptor or the laptop side where the prob
is..


It's their way of locking you in to buying genuine parts only. :-/

"bless" them

Jim K

Jim K wrote:

do laptop chargers "sense" and adjust their output somehow?? meaning I
can't actually say 100% it's the charger that's shagged & just acquire
a new one...?

Is it one of the Dell ones with a pin inside the barrel? Even then I
think the 3rd connection is for the laptop to sense the charger, not
vice-versa.

On Jul 2, 6:59 pm, Bernard Peek wrote:
On 02/07/12 12:39, Jim K wrote:

Mate's Dell Laptop (oldish) has flat batt and won;t boot.

Plug in to mains charger - won;t charge - batt light on lappy "winks"
once per insertion of the jack, then nought.

A possible cause is a broken connection between the laptop's power
socket and the motherboard. Try jiggling the connector about and see
whether the power light winks at you.

yeah we tried all manner of jiggly approaches and could only get one
"wink" per insertion of the jack plug...

Another possible fault is a short-circuit causing the power supply to
shut down as soon as you plug it in.

pretty sure the green led on the tranny part of the adaptor was lit
throughout - I read elsewhere that it should? go out if theres a short
presented to it?


Power input sockets are a weak-point in laptop construction. A component
costing pennies can stop the whole machine from working. And when
someone trips over the power cable the tug is transmitted to the socket.

joy ;))

Jim K

On Jul 2, 7:00 pm, Andy Burns wrote:
Jim K wrote:
do laptop chargers "sense" and adjust their output somehow?? meaning I
can't actually say 100% it's the charger that's shagged & just acquire
a new one...?

Is it one of the Dell ones with a pin inside the barrel? Even then I
think the 3rd connection is for the laptop to sense the charger, not
vice-versa.

yup - the stated 19.4v is presented between the outer and inner
surfaces of the barrel part.
the central pin is the third data connector i believe (now ;))
that measures -12v when measured from the inner (19.4v) part of the
barrel

anyone know if it's correct like that? if so its the laptop end that's
at fault...

Jim K

On Jul 2, 7:02 pm, Jim K wrote:
On Jul 2, 6:59 pm, Bernard Peek wrote:

On 02/07/12 12:39, Jim K wrote:

Mate's Dell Laptop (oldish) has flat batt and won;t boot.

Plug in to mains charger - won;t charge - batt light on lappy "winks"
once per insertion of the jack, then nought.

A possible cause is a broken connection between the laptop's power
socket and the motherboard. Try jiggling the connector about and see
whether the power light winks at you.

yeah we tried all manner of jiggly approaches and could only get one
"wink" per insertion of the jack plug...

Another possible fault is a short-circuit causing the power supply to
shut down as soon as you plug it in.

pretty sure the green led on the tranny part of the adaptor was lit
throughout - I read elsewhere that it should? go out if theres a short
presented to it?

Power input sockets are a weak-point in laptop construction. A component
costing pennies can stop the whole machine from working. And when
someone trips over the power cable the tug is transmitted to the socket.

joy ;))

Jim K

well I just rather destructively proved that the DC lead was in fact
OK for conitinuity (no shorts/breaks)....

at the power supply end I have to report I cocked up earlier (above)
as:-

the 6k ohm resistance is between the outer screen (GRND) and the
inner screen NOT between the inner screen and the central "data" pin

according to the google found repairer:-

http://newsgroups.derkeiler.com/Arch.../msg00237.html

with power off, these 3 should all be open circuit in all
permutations1&3; 2&3 - they ain't in mine (and it's not the cable)

Jim K

"Jim K" wrote in message
...
Mate's Dell Laptop (oldish) has flat batt and won;t boot.

Plug in to mains charger - won;t charge - batt light on lappy "winks"
once per insertion of the jack, then nought.

Lappy won't boot either when plugged in to the charger...?

Had batt out & makes no difference except the batt light "wink"
disappears when you shove the jack in.

Got charger here now, plugged in, green LED on tranny box is lit,
multimeter on the DC jack end - measuring 0.01V - it's rated on the
tranny label at 19.5v 3.3A....

Seems something not right - but :-

do laptop chargers "sense" and adjust their output somehow??

Normally they don't.

meaning I can't actually say 100% it's the charger
that's shagged & just acquire a new one...?

That's a pretty fair bet.

"Jim K" wrote in message
...
On Jul 2, 12:53 pm, "Man at B&Q" wrote:
On Jul 2, 12:39 pm, Jim K wrote:



do laptop chargers "sense" and adjust their output somehow?? meaning I
can't actually say 100% it's the charger that's shagged & just acquire
a new one...?

All help appreciated

Cheers
Jim K

All the "chargers" I've seen are just switch mode power supplies.
Indeed, the generic replacements (rather than branded) ones make very
good power supplies for other uses. Shouldn't cost mor ethan £20 for a
new one.

The charging intelligence is in the laptop and/or battery.

MBQ

Righto.

So I chopped the jack of the end to reveal a 3 core cable (which
surprised me a bit - was expecting 2)

There's an outer screen of decent multistrand (1) , then inside that
another smaller screen (2) & a core (3)

Now I can indeed get 19.5 from the bare end from the tranny -across 1
& 2
When I test across from 3 to 2 - i get 12.5v...

On the jack plug end (now removed and opened up to check) there are
indeed 3 connections - Outer screen (1) to outside of jackplug, inner
screen (2) to (appears to be) the inner surface of the jackplug ??, &
Central core (3) to centre pin.

Is this making any sense to anyone?

Its likely documented on the net but you didn't specify the laptop model
etc.

In article
,
Jim K wrote:
Mate's Dell Laptop (oldish) has flat batt and won;t boot.

Plug in to mains charger - won;t charge - batt light on lappy "winks"
once per insertion of the jack, then nought.

Lappy won't boot either when plugged in to the charger...?

Had batt out & makes no difference except the batt light "wink"
disappears when you shove the jack in.

Got charger here now, plugged in, green LED on tranny box is lit,
multimeter on the DC jack end - measuring 0.01V - it's rated on the
tranny label at 19.5v 3.3A....

Seems something not right - but :-

do laptop chargers "sense" and adjust their output somehow?? meaning I
can't actually say 100% it's the charger that's shagged & just acquire
a new one...?

All help appreciated


I have three laptops of various makes and ages, and all will work off
their PS with no battery at all.

--
*Change is inevitable, except from a vending machine*

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