Re: Sharp Aquos LC-60LE652E - Blank screen, no sound, steady blue LED
Hey guys,
thank's for helping me. I try to get a main board. If I have tested, I'll come back with the results.
Martin_Silberkuhl
Member
Last Activity: 07-20-2017, 12:11 AM
Joined: 07-13-2017
Location: Wiggensbach
-
Re: Sharp Aquos LC-60LE652E - Blank screen, no sound, steady blue LED
No, what I mean is, what is the next step?
Without a circuit diagram it's not really easy. Normally I would check the voltages on all ICs, but I don't know which voltages.
What would you do?Leave a comment:
-
Re: Sharp Aquos LC-60LE652E - Blank screen, no sound, steady blue LED
yes dick, it was me.
With BGAs on your board, sometimes it could be a possibility to repair, by heating it. But I had no success and the connectors were damaged (but no problem for me).
Other idea: Do you know if there is an extra power-preparation on the mainboard to supply the ICs?Leave a comment:
-
Re: Sharp Aquos LC-60LE652E - Blank screen, no sound, steady blue LED
Hey dick,
[COLOR="Blue"]Could you try and jumper PWM1 & also PWM2 of one of the IC's to 5V using resistors and see if that clears the fault condition for that IC. Again with the mainboard disconnected and the other jumpers in place.
Data sheet does say PWMx = H; 2.0V to 5.5V[/COLOR]
OK, I connect my frequency generator to PWM1 of the connector, comming from mainboard + the other jumper in place.
Settings are: puls-signal, f=10kHz, V=5V
...Leave a comment:
-
Re: Sharp Aquos LC-60LE652E - Blank screen, no sound, steady blue LED
I think the detection condition table is more meaningful.
Reading it, I think we have no Problem.
btw. - I measured the PWM1-Signal with my Oszilloscope, which should come from the Mainboard, but no Signal. So as I stated earlier, I think the failure is on the Mainboard.
What do you think and do we have a possibility to search on that board?...Leave a comment:
-
Re: Sharp Aquos LC-60LE652E - Blank screen, no sound, steady blue LED
[COLOR="Blue"]With Reg90 at 0V this disables the Gate1 & 2 drives and also Dimout1 & 2 drives. So something is switching off the Reg90 supply. What voltage is on UVLO (Pin 17).
[/COLOR]
Pin 17: +5,66VRe: Sharp Aquos LC-60LE652E - Blank screen, no sound, steady blue LED
[COLOR="Blue"]With Reg90 at 0V this disables the Gate1 & 2 drives and also Dimout1 & 2 drives. So something is switching off the Reg90 supply. What voltage is on UVLO (PinLeave a comment:
-
Re: Sharp Aquos LC-60LE652E - Blank screen, no sound, steady blue LED
[B]@dick[/B]
[COLOR="Blue"]That voltage appears to be correct. So you have the supply voltage and the STB voltage (On/OFF) for both IC's but no boosted LED voltages (117.8V)
It would be unusual to find that both IC's are failing to boost the voltage needed to drive the leds.
Out of curiosity what voltages do you have on pin 23 (Reg90) which should be 9.0V and pin 12 (FailB) which should be at a High level.[/COLOR]
pin 23: 0V
pin 12: 0V
...Leave a comment:
-
Re: Sharp Aquos LC-60LE652E - Blank screen, no sound, steady blue LED
Hey dick,
[COLOR="Blue"]MDHT4N20Y & MDD7N20C
Check between the Drain and Source, set powered off and with your meter in diode mode and you should see a diode reading one way and open circuit when you swap your meter probes around. There should be no short circuit between any of the pins of the mosfets.[/COLOR]
As I've already measured in one way 0,56V, the other way "open circuit" and no short circuit.Re: Sharp Aquos LC-60LE652E - Blank screen, no sound,Leave a comment:
-
Re: Sharp Aquos LC-60LE652E - Blank screen, no sound, steady blue LED
Hey dick,
[COLOR="Blue"]12V is within the operating voltage range for those IC's
What voltage do you have on Pin 2 of each of them which should be >2V[/COLOR]
I measure +4,68V
[COLOR="Blue"]I would check all the mosfets/diodes around those IC's. The 4 above and the 4 below the IC's[/COLOR]
see attachement
I'm not realy sure, if the mosfet's are defect, but normally there should be overload between Source and...Leave a comment:
-
Re: Sharp Aquos LC-60LE652E - Blank screen, no sound, steady blue LED
Hello guys,
hope you had a good weekend. The following things I have done in the morning:
@budm
[COLOR="Blue"]You need to use chassis GND.
That 90V is the Voltage for feeding the Voltage Boost converter circuit to supply the Voltage to run the backlights LEDs.
You also need to do this test:
1) Turn the TV off.
2) Leave the DCV meter BLACK PROBE on the chassis, and Red probe on the LED+
3) Keep an eye on the TV and see how high the...Leave a comment:
-
Re: Sharp Aquos LC-60LE652E - Blank screen, no sound, steady blue LED
Hi there,
I really don't know, but because I can't switch the tv in stand-by I suppose the failure on the main-board. But let's stay in this systematically mode.Leave a comment:
-
Re: Sharp Aquos LC-60LE652E - Blank screen, no sound, steady blue LED
Hey Dick,
[COLOR="Blue"]You should have sound and be able to see a picture using a bright light source (torch) shone onto the screen and looking carefully.[/COLOR]
I tested it in the morning and I have no sound and no picture, also not using the torch.Re: Sharp Aquos LC-60LE652E - Blank screen, no sound, steady blue LED
Hey Dick,
[COLOR="Blue"]You should have sound and be able to see a picture using a bright light source (torch) shoneLeave a comment:
-
Re: Sharp Aquos LC-60LE652E - Blank screen, no sound, steady blue LED
Hey Budm,
I measured the 0V between LED+ and LED-, not with ref to the chassis GND.
The DCV between the two legs of cap C901 is +90V.Leave a comment:
-
Re: Sharp Aquos LC-60LE652E - Blank screen, no sound, steady blue LED
Hey Dick,
the ICs U901A and U901B are both BD9483F (White LED Driver for large LCD
Panels - DCDC Converter type).Leave a comment:
-
Re: Sharp Aquos LC-60LE652E - Blank screen, no sound, steady blue LED
OK, the value of resister is brown, black, green, brown, brown -> 1050 OhmLeave a comment:
-
Re: Sharp Aquos LC-60LE652E - Blank screen, no sound, steady blue LED
[COLOR="Blue"]When you initially power on and come out of standby what voltage do you have on the led connectors? Initially it may peak and then drop suddenly.[/COLOR]
0V
[COLOR="Blue"]If no voltage then with the power off, check all the diodes with your meter set to diode mode.[/COLOR]
All diodes have about 0,46V forward voltage, except the 1N... . They have about 0,6V (that's normal).
D402 and D401 have 0,2V and D207 0,3V.
...Leave a comment:
-
Re: Sharp Aquos LC-60LE652E - Blank screen, no sound, steady blue LED
Both 1kOhm, as you suggest.Leave a comment:
-
Re: Sharp Aquos LC-60LE652E - Blank screen, no sound, steady blue LED
First issue I can test tomorrow.
Second issue "jumper...." I've done (see photo).
After jumpering I can measure 5V on BL_ON and PS_ON, but no effect, so no
backlight.
Also the voltages on LED1+/LED1-, LED2+/LED2-,... are 0V.
Further suggestions?...Leave a comment:
-
Re: Sharp Aquos LC-60LE652E - Blank screen, no sound, steady blue LED
OK, here we go:...Leave a comment:
-
Sharp Aquos LC-60LE652E - Blank screen, no sound, steady blue LED
Hi there,
I've a problem with a Sharp TV.
If I plug-in, only the turned "V" lights blue steadily. I cannot switch into stand-by, not with the power sensor button on the front, not with the remote control. Remote control ist working because if I press a button the "V" starts to flicker. If I connect my laptop via HDMI, no picture and no sound appears.
Following actions I did, but had no effect:
- hold VOL down and INPUT buttons at the same time, then press POWER
- measure all voltages on the right connector...
No activity results to display
Leave a comment: