Re: Inverter or Backlight?
Also something simple to check but make sure the lid switch is not stuck. I had this on an older notebook, to cause backlight to shut off. Usually t will also cause system to enter standby mode as well.
kb48
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Last Activity: 11-20-2011, 12:29 AM
Joined: 11-02-2011
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Re: Inverter or Backlight?
99% of time it is the inverter, due to usually liquid spill or just the transformer or ceramic/polymer caps die on the inverter.
Simple test, take and unplug the FL lamp from the inverter, take a clip lead ground it to the notebook hinge, and turn on notebook. Carefully bring the other end of cliplead near the plug of the FL lamp (white or pink wires). and if it draws a spark or arc then inverter ok. Have to do this when first turned on, as the inverter will just shutdown otherwise.
Using meter carefully proble the other plug,...Leave a comment:
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Cornerstone 17" LCD monitor (white)
Ran into a rather unique problem on this monitor.
Powers on displays garbled lines all over screen, horizontal lines.
Suspected may have been bad caps and so above the center processing IC
I spot 4 caps, at least 1 looked suspect. Replaced all four and still same problem. (Replaced with slightly higher voltage rating as well).
So I see the control chip is SMC8384-140 surface mount about 80 pin.
Anyhow, I am then trying hair dryer method to see results.
While feeding video, and heating this chip, first image grew with white lines, then lines started... -
Re: Vizio SV420XVT1A Delta DPS284BPA only 5V
I have isolated it to IC601 and I got a DPS199 board to make my next attempt to replace the bad IC. It has the 5V standby, and jump 5V to PS-ON I get 12.8 frequency and voltage trying to drive the IC601 which appears to be shorted, so it never turns on the 12 or 24V sources.
Oddly at this point I cannot tell if the mainboard is good or bad, until we get decent power from the Power Supply first. The mainboard never produced the 3.3V for the PS_ON pin 1 however without the power supply working, it is hard to say. I can say the processor...Leave a comment:
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Re: TV free off the curb
Red or blooming is sign of weak CRT. You have 2 choices. Cut back on the G2 bottom knob on the flyback, which will lower the brightness to where it no longer bleeds out, or replace the CRT. Last solution obviously not worth the effort. Years ago you used to be able to try to restore the guns, but that was only a band aid solution that could also blow out the tube. Some people can adjust the blue and green drive and cutoff trimmers on the CRT board, to sometimes get a little more life.
Considering the time to spend doing all this stuff, you...Leave a comment:
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Re: TV free off the curb
Buzz in audio is tweak the last stage of IF in the set coil that seperates out the audio, or could be aged out, but considering it all may just be sloppy design. Red blotch is purity. Either the degauss coil got unplugged or where it has been tossed around part of the CRT is magnetized. Take a soldering gun, place it at center of tube, turn on and slowly rotate it in circles and slowly move it away from the tube at the same time.
Turn it off when your at least 2 feet away. You will see the red go away or change a little at least. If that dont work...Leave a comment:
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Re: VIZIO XVT373SV Not powering on
Ok now that I had time for more study here is what I fond.
Pin 1 pson was mwant to go high when set demands power. The relay seems to click but is bringing higher current onlyn when mainboard calls to turn on. With it on U601 is supposed to switch on and run 12 and 24 power. There is a foil runniung from a SMT and on 1 side from AC ground I get 12.8V however nothing going to the chip. I tried a 1000 ohm resistor to try to drive it and discover it is koading that down so the chip must be shorted and failed.
Sadly I think it got too...Leave a comment:
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Re: Help Vizio VW32LHDTV10A no pix no sound no backlight
Mine is similar. However how hot is normal for the processor? I think it would get warmer when in use. Mine gets quite warm but all the voltages are still normal.
Mine just has P/S problems, and today I am going to try soldering around on the P/S to see if it will revive the missing 12 and 24 section.
I would love to know what PIN 1 of J1 the PS_ON voltages are when set is in standby and when set is on. When I attempt to strap mine to 3.3 or 5v it only causes the relay to click amd shut down the P/S as it is normally...Leave a comment:
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Re: VIZIO XVT373SV Not powering on
On my 42" The delta DPS284AP this pin (Pin1) PS_ON seems to be standby when it is high. (Service manual indicate it go to 3.3V) and causes the relay to turn on which removes 110V but leaves the 5V running from another source, which is the small switching transformer. Thus it seems to be off when high and on when low. My PS however being partially dead, just staying off.
Not supplying chopping freq to the 2 Driver transistors and no reponses from the OPTO couplers. I am not sure how they manage to regulate the 12V and...Leave a comment:
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Re: Vizio VO42L FHDTV10A will not turn on...
Delaing with the DPS284AP supply which is similar. I have been looking at the 26 pin chip, which seems to run the Main Supply side, of 24 and 12V sources.
I cannot see any numbers to ID that chip, which I think is bad.
The PS comes on with the 5V ok, but nothing else.
When I attempt to bias the PS_ON with either 3.3 or 5V it seems to engage the relay which then kills power to the input I.E. 164VDC primary. That relay is in series with 110 AC but it is setup normally closed. So it seems then...Leave a comment:
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Re: Vizio Service Port Contact Kills Mainboard
Mine has a plastic dummy plug stuck in it. But if you did not read the label then it is the same pins and shape as a USB.
The HDMI sockets however are beside it, and not mistakeable, but shocks me that it would blow the set so easily.
Of course my set is still dead, I need a new P/S at least I am hoping.
It has the 5V and processor gets warm to mildly hot, I was able to hit the power key enough that the VIZIO logo stays white but the 5.2 LED at the bottom came on when I hit power button, but since...Leave a comment:
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Vizio SV420XVT1A Delta DPS284BPA only 5V
Trying to revive a dead Vizio 42inch LCD TV.
Looking at the PS revealed no swollen caps.
Here is what is happening.
Set has been worked on, had the D907 removed.
I replaced it, maybe not right ?? with a double diode from some IBM AT supply.
First power up, the 5V jumpos up and down only to 3 v then to 0.
So I looked on mainboard, and yanked the cable going from the right side input block and now 5V came back at a steady 5.21V.
However no other power, punching on button no soap. No 12V or 24V come up.
Tried... -
ILO TV32HD solving Mainboard Problem?
Have a very used ILO 32HD model TV.
Problems, started that the set would not turn on the PS_A line.
Per info on the web, I jumped the PS_A line and set turned on.
For 3 hours ran fine, I was able to use the remote to function everything, BUT noticed that when using remote, the picture would flash with every key press.
The top panel buttons however, no good. I see they are using a resistor per key method, for those functions.
After 3 hours use, now the set is stuck in Composite and 1/2 volume.
No remote response anymore.
Turned off... -
Re: ILO LCT27HA36 TV, no picture but sound
This thread is probably outdated, but if the FL tubes go bad, it would be unlikely that they all died at the same time since you probably have 5-7 of them spread out a couple inches apart or so. If the tube goes bad, it will be discolored at one end, just like a bad fl light used in your home. The difference is the inverters that light the tubes, have a circuit that senses when the tube is about to fail, that it is not drawing enough current, and will then shut down the inverters. However they usually allow the fl tubes to initially light...Leave a comment:
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