CCFL & Inverter problem
benitos
Have a Toshiba Satellite laptop with a "no display" symptom.
After checking it, i can notice a very dim picture , the CCFL doesn't
lit.
After opening it , I found that the inverter had a fuse open .
Replace the fuse but after , the computer did not power up.
There was a short on the inverter boards so I replaced it with the
same model.
Now , the computer boots up , CCFL lit for a few seconds but shuts
down after.
Is is possible the the CCFL is bad also ?
Thanks for your help...
Ken
What model is your Toshiba Satellite??
N_Cook
news:913e4add-5584-431f...@w18g2000yqc.googlegroups.com...
Any disc ceramic C , leaky, with the tube?
Plai...@yawhoo.com
It's possible. When the image first appears, is there a pinkish hue?
Also, inspect the wires from the inverter to the CCFL carefully.
PlainBill
benitos
>
> - Afficher le texte des messages précédents -
Model is P200-MB1
Only half of the CCFL lit (kind of pink) and shuts down.
JW
wrote in Message id:
<7374011d-9cbe-49a2...@c19g2000yqe.googlegroups.com>:
Sounds like it could be a tube. Most inverters have a controller which
will shut down if the load of the tube is not correct. Best to replace
both.
Plai...@yawhoo.com
That indicates the tube is old, and dying. It gets a pinkish tint
and the current rises. Replace the tube and you will have a good
display.
PlainBill
benitos
>
> - Show quoted text -
OK , thank you all.
N_Cook
news:7ap7571g82d5hcnhl...@4ax.com...
Does one inverter supply two tubes? And if disconnecting the problematic
tube , as a proving exercise, do you have to mitigate for overdrive to the
single tube, even for say 5 seconds of proving use?
Franc Zabkar
>Model is P200-MB1
FYI, here are circuit diagrams ...
TOSHIBA Satellite P200 P205 - COMPAL LA-3441P ISRAA - REV 0.1.pdf
http://www.4shared.com/get/2082TS5c/TOSHIBA_Satellite_P200_P205_-_.html
TOSHIBA Satellite P200 P205 - COMPAL LA-3711P - REV 1.0.pdf
http://www.4shared.com/get/c0cOnc2A/TOSHIBA_Satellite_P200_P205_-_.html
- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
N_Cook
news:fse957dgg34a2mc3n...@4ax.com...
Impressive component level schema except not inverter + backlight? in less
than 1.4 Meg pdfs
Control line BKLT references but not what it is controlling AFAICS
Plai...@yawhoo.com
wrote:
><Plai...@yawhoo.com> wrote in message
>news:7ap7571g82d5hcnhl...@4ax.com...
>> On Mon, 22 Aug 2011 14:19:37 -0700 (PDT), benitos
>> <bente...@gmail.com> wrote:
>>
>> >On 22 ao�t, 15:28, PlainB...@yawhoo.com wrote:
>> >> On Mon, 22 Aug 2011 08:37:16 -0700 (PDT), benitos
>> >>
>> >>
>> >>
>> >>
>> >>
>> >> <bentech2...@gmail.com> wrote:
>> >> >Hi ,
>> >>
>> >> >Have a Toshiba Satellite laptop with a "no display" symptom.
>> >>
>> >> >After checking it, i can notice a very dim picture , the CCFL doesn't
>> >> >lit.
>> >>
>> >> >After opening it , I found that the inverter had a fuse open .
>> >>
>> >> >Replace the fuse but after , the computer did not power up.
>> >>
>> >> >There was a short on the inverter boards so I replaced it with the
>> >> >same model.
>> >>
>> >> >Now , the computer boots up , CCFL lit for a few seconds but shuts
>> >> >down after.
>> >>
>> >> >Is is possible the the CCFL is bad also ?
>> >>
>> >> >Thanks for your help...
>> >>
>> >> It's possible. When the image first appears, is there a pinkish hue?
>> >> Also, inspect the wires from the inverter to the CCFL carefully.
>> >>
>> >> PlainBill- Masquer le texte des messages pr�c�dents -
>> >>
>> >> - Afficher le texte des messages pr�c�dents -
>> >
>> >Model is P200-MB1
>> >
>> >Only half of the CCFL lit (kind of pink) and shuts down.
>> That indicates the tube is old, and dying. It gets a pinkish tint
>> and the current rises. Replace the tube and you will have a good
>> display.
>>
>> PlainBill
>
>
>Does one inverter supply two tubes? And if disconnecting the problematic
>tube , as a proving exercise, do you have to mitigate for overdrive to the
>single tube, even for say 5 seconds of proving use?
>
It varies with the design. I'm more familiar with the full fledged
inverters found in monitors, but it is very common to see one inverter
system driving 4 or even more tubes. The 'system' consists of a
single controller, drivers driving 1 to 6 (or more) transformers, and
each transformer driving one, two or four tubes. The system contains
circuitry which monitors the current through and the voltage across
each tube. The largest single part of the circuit is the transformer,
and even those can be less than 12mm (1/2") on a side.
PlainBill
Plai...@yawhoo.com
wrote:
Here's a schematic and photos of a laptop inverter.
http://schematic-laptop.blogspot.com/2011/03/laptop-inverter-schematic.html
This particular design is rather feature poor, but does include over
current protection, but apparently no open lamp protection.
PlainBill
Jim Yanik
news:23ga57p6aa1jqbghj...@4ax.com:
one way to find out how your particular inverter circuit works is to find
the datasheet for that particular inverter-driver IC. (DAGS)
the datasheet usually has sample schematics,and describes the control
lines,etc.
--
Jim Yanik
jyanik
at
localnet
dot com
N_Cook
news:clea57d4cas684gdg...@4ax.com...
> On Wed, 24 Aug 2011 08:26:30 +0100, "N_Cook" <div...@tcp.co.uk>
> wrote:
>
> ><Plai...@yawhoo.com> wrote in message
> >news:7ap7571g82d5hcnhl...@4ax.com...
> >> On Mon, 22 Aug 2011 14:19:37 -0700 (PDT), benitos
> >> <bente...@gmail.com> wrote:
> >>
> >> >On 22 août, 15:28, PlainB...@yawhoo.com wrote:
> >> >> On Mon, 22 Aug 2011 08:37:16 -0700 (PDT), benitos
> >> >>
> >> >>
> >> >>
> >> >>
> >> >>
> >> >> <bentech2...@gmail.com> wrote:
> >> >> >Hi ,
> >> >>
> >> >> >Have a Toshiba Satellite laptop with a "no display" symptom.
> >> >>
> >> >> >After checking it, i can notice a very dim picture , the CCFL
doesn't
> >> >> >lit.
> >> >>
> >> >> >After opening it , I found that the inverter had a fuse open .
> >> >>
> >> >> >Replace the fuse but after , the computer did not power up.
> >> >>
> >> >> >There was a short on the inverter boards so I replaced it with the
> >> >> >same model.
> >> >>
> >> >> >Now , the computer boots up , CCFL lit for a few seconds but shuts
> >> >> >down after.
> >> >>
> >> >> >Is is possible the the CCFL is bad also ?
> >> >>
> >> >> >Thanks for your help...
> >> >>
> >> >> It's possible. When the image first appears, is there a pinkish hue?
> >> >> Also, inspect the wires from the inverter to the CCFL carefully.
> >> >>
> >> >>
> >> >> - Afficher le texte des messages précédents -
> >> >
> >> >Model is P200-MB1
> >> >
> >> >Only half of the CCFL lit (kind of pink) and shuts down.
> >> That indicates the tube is old, and dying. It gets a pinkish tint
> >> and the current rises. Replace the tube and you will have a good
> >> display.
> >>
> >> PlainBill
> >
> >
> >Does one inverter supply two tubes? And if disconnecting the problematic
> >tube , as a proving exercise, do you have to mitigate for overdrive to
the
> >single tube, even for say 5 seconds of proving use?
> >
> It varies with the design. I'm more familiar with the full fledged
> inverters found in monitors, but it is very common to see one inverter
> system driving 4 or even more tubes. The 'system' consists of a
> single controller, drivers driving 1 to 6 (or more) transformers, and
> each transformer driving one, two or four tubes. The system contains
> circuitry which monitors the current through and the voltage across
> each tube. The largest single part of the circuit is the transformer,
> and even those can be less than 12mm (1/2") on a side.
>
> PlainBill
I was wondering , with a shared inverter, how they avoided possibility of
one tube striking and the other one not .
Plai...@yawhoo.com
wrote:
Matched tubes? Good design? Shared transformer designs also have
small capacitors between the hot side of the transformer and each
CCFL.
If you google the part number of many inverter controllers you can
find extensive information on how to design an inverter.
PlainBill
Jim Yanik
news:n8gd57hcl4v8f2ort...@4ax.com:
I've read that that cap acts as a short(low-
Z load) until the tube fires,then the tube is lower resistance.
benitos
>
> - Show quoted text -
Hi , changed the INVERTER and CCFL and samething. Tube lit only half
and shuts down after a few seconds...
Any clue ?