I have a 26" benq monitor/tv Model: dv2680. It has 8 ccfl's backlights and one is bad. In lieu of replacing it, can someone tell me how to fake it out or bypass it. Its viewable with 7 of them working...Thanks
Sam
Collapse
X
-
Tags: None
-
Re: Sam
Originally posted by squiddiddlerI have a 26" benq monitor/tv Model: dv2680. It has 8 ccfl's backlights and one is bad. In lieu of replacing it, can someone tell me how to fake it out or bypass it. Its viewable with 7 of them working...Thanks
Second, use a more descriptive thread/topic name.
Third, look around for Dummy Load. I think PlainBill would be able to help you in that topic, as I do not have enough knowledge to serve you ...There are 10 kind of people in this world: those that understand binary, and those who don't.- ASUS ROG Maximus IX Code
- Intel Core i5-7600K 3.8GHz
- 16gb GSKILL TridentZ RGB DDR4-3200
- 1 M2 SSD + 2 WD Blue 1TB (Mirrored)
- Windows 10 Pro x64
- GeForce GT1050
2 x Acer KA240H + 1 Vewsonic VP2130 21 (a cap replacement job)
-
Re: Sam
Originally posted by squiddiddlerI have a 26" benq monitor/tv Model: dv2680. It has 8 ccfl's backlights and one is bad. In lieu of replacing it, can someone tell me how to fake it out or bypass it. Its viewable with 7 of them working...Thanks
I mentioned those because I'm not going to infer a relationship between those names and what you are trying to do.
In general, here is the theory. Measure the voltage across and the current through a working CCFL. Calculate the equivalent resistance and power dissipation of the CCFL. I.E. If there is 780 V at 8.3 ma through a good CCFL the equivalent resistance is 94K ohm. 100K ohm is close enough. It was dissipating 6.5 watts, better use a 10 Watt resistor.
Now the problem is your typical DMM won't accurately measure the voltage or the current. The best solution is to pick up a range of 10 Watt resistors and try them until you find the highers value that works, then go down 10%.
Of course, by the time you have done that you will have spent more than you would pay for a new CCFL, and you won't have to be annoyed by people asking why there is a dark band across the screen.
PlainBillFor a number of reasons, both health and personal, I will no longer be active on this board. Any PMs asking for assistance will be ignored.
Never be afraid to try something new. Remember, amateurs built the ark. Professionals built the Titanic.Comment
-
Re: Sam
Originally posted by PlainBillGreetings. I just returned from a day escorting my Grandson around Disneyland. He got to see Buzz Lightyear, have his picture taken with Goofy, ride on Dumbo, and play in Mickey Mouse's Toonland.
I mentioned those because I'm not going to infer a relationship between those names and what you are trying to do.
In general, here is the theory. Measure the voltage across and the current through a working CCFL. Calculate the equivalent resistance and power dissipation of the CCFL. I.E. If there is 780 V at 8.3 ma through a good CCFL the equivalent resistance is 94K ohm. 100K ohm is close enough. It was dissipating 6.5 watts, better use a 10 Watt resistor.
Now the problem is your typical DMM won't accurately measure the voltage or the current. The best solution is to pick up a range of 10 Watt resistors and try them until you find the highers value that works, then go down 10%.
Of course, by the time you have done that you will have spent more than you would pay for a new CCFL, and you won't have to be annoyed by people asking why there is a dark band across the screen.
PlainBillThere are 10 kind of people in this world: those that understand binary, and those who don't.- ASUS ROG Maximus IX Code
- Intel Core i5-7600K 3.8GHz
- 16gb GSKILL TridentZ RGB DDR4-3200
- 1 M2 SSD + 2 WD Blue 1TB (Mirrored)
- Windows 10 Pro x64
- GeForce GT1050
2 x Acer KA240H + 1 Vewsonic VP2130 21 (a cap replacement job)
Comment
-
Re: Sam
Originally posted by WizardYes this is what is done to load test the lamp inverters. Even in few service manuals spells this out.
and 96K is too low, I recall around 120K and yes use 10W sand bar because of high KV.
Cheers, Wizard
PlainBillFor a number of reasons, both health and personal, I will no longer be active on this board. Any PMs asking for assistance will be ignored.
Never be afraid to try something new. Remember, amateurs built the ark. Professionals built the Titanic.Comment
Related Topics
Collapse
-
by ttmi100xGreetings everyone,
I have a HANNSG Hi221 monitor that exhibits two seconds to black issues (backlight goes off, display is still on as confirmed by shining a flashlight on it) with some additional oddities...
The monitor failed on me with a standard "2 seconds to black" some time ago prompting me to initially replace most of the electrolytic capacitors (some of them were bulging/leaking).
Things kinda sorta worked for a night, then the problem returned along with some flickering and "buzzing" noises.
Upon closer inspection...6 Photos-
Channel: Troubleshooting Computer Displays
-
-
by mikey5791Hi,
This monitor previously is my main working monitor which i have been using for 8~9 years. Yesterday, when i switched on my pc from fresh to power on, the monitor is just black no display. I started dismantle to look inside the monitor power board but nothing looks suspicious or burnt. So i took my external ccfl inverter to try to power the monitor ccfl lamps which consisted of 2 lamps on upper part and 2 lamps on the lower part.
Found out the upper ccfl lamp which is supposed to connect to cn304 on the power board did not light up. Then i installed a used working...-
Channel: Troubleshooting Computer Displays
-
-
by caseyjay_48I am currently on a troubleshoot of 46” Sony KDL-46BX450 tv. I came back from Washington to Texas on medical emergency and had to leave all my tools up there. All I have is a couple of screwdrivers and a dvm. I wish to ask the community a troubleshooting question. Please forgive stupid questions as meds I am taking produce brain fog.
I have well maintained Sony KDL-46BX450. It went black one day. After turn-on, I get solid green light and Sony logo in screen center for about 1-2 seconds, then black. No blinking LEDs, no hissing. Flashlight test shows screen characters dimly viewable,... -
by seppdeHello everyone,
I've got a Benq power board of a XL2540K monitor which suffered from a power cut and is since defective / won't turn on. It's got obvious defects, some blown resistors, some burning around the drain pin of a MOSFET...
... and some 6-pin IC I struggle identifying, that is driving said MOSFET.
The IC is labeled as IC601, so someone with a circuit schematic could probably identify it really quick, unfortunately I can't find the schematics.
In other power boards of Benq for which I did find the schematics, IC601 is an 8-pin NCP1200 PWM controller - I suppose...2 Photos-
Channel: Troubleshooting Computer Displays
-
-
by AJ847.63eHi All.
Does anyone have any reference materials or something I can use to try troubleshooting a BenQ TH681? Google unfortunately has turned up zip. I did find a service manual for a W series BenQ but that is pretty much useless, it's more a glorified user manual. A list of voltages would be great as I suspect my mainboard is faulty, the colour wheel voltage is not dipping like it should.
The one I am troubleshooting now was originally overheating after a lamp replacement. It originally would take 2 minutes or so for it to shut off and blink the temp and lamp lights... - Loading...
- No more items.
Comment