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...
What model is your Toshiba Satellite??
Any disc ceramic C , leaky, with the tube?
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
Model is P200-MB1
Only half of the CCFL lit (kind of pink) and shuts down.
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.
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
?
OK , thank you all.
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?
On Mon, 22 Aug 2011 14:19:37 -0700 (PDT), benitos put finger to keyboard and composed:
FYI, here are circuit diagrams ...
TOSHIBA Satellite P200 P205 - COMPAL LA-3441P ISRAA - REV 0.1.pdf
TOSHIBA Satellite P200 P205 - COMPAL LA-3711P - REV 1.0.pdf
- Franc Zabkar
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
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
doesn't
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I was wondering , with a shared inverter, how they avoided possibility of one tube striking and the other one not .
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
snipped-for-privacy@yawhoo.com wrote in news: snipped-for-privacy@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.
?
Hi , changed the INVERTER and CCFL and samething. Tube lit only half and shuts down after a few seconds...
Any clue ?
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