purchased on the alixpress smd ic cfc6 this and the link http://www.aliexpress.com/snapshot/6521240388.html?orderId=66056666467718 but I received another code ic and the CFCA what difference there between the two components, because I problems of image lcd, I add in this section because I bought the w373 always on alixpess and this is identical as the theme, the problem can not display the image perfectly, can you help?
Somebody help me here I asked a help identifying ic SOT23 with initials w373 but what already suggested can not be right because the pin 2 on motherboard goes gnd watching the pdf of that suggested the gnd pin and 3rd, I checked that this componentIt is used to power some of the pin display
This picture above seems as internal LCD panel failure. I assume before changing mentioned SMD part were none picture on LCD visible. Video contens is present but vertical strokes points to drivers failure or bad flex-to-glass connections. If possible try change LCD panel for test.
But it seems not so, I've tested with another display, download the pdf of the LCD to see that some power supplies lack AT070TN92 increasing supply with external power supply to pin 43 for Power Analog Circuit display begins to improve in vivid colors pui attach the photo:
It seems as PLC controller display of some sort with LCD panel supplied externally.
With non symmetric VD+ and VD- voltages liquid crystal will be degraded. If these voltages was too low maybe similiar efffect as observed.
What are voltages on 22uF/16V capacitors from first photo - looks as DC-DC converters outputs for LCD drivers?
This panel has 5V digital supply, 6,5 to 13V analog and two switch supplies - VGH, VGL. I Asssume so problem exist with VGH and VGL converter units.
Checking these units will be unavoidable. Abovementioned SMD element is part one converter circuit. Autor must trace partial schematic from board and locate position and function this element. Below attached datasheet this LCD.
These IC coded as CFCA and W373 are probably DC-DC converter controllers with power switches - located near bypass caps and chokes.
Edit2: Maybe this: Link
Now the component w373 can not remember if I trashed but now has been replaced with that of the second post that as said before the pin and gnd other than that required by the component suggested, I can say that the voltage required by the LCD, there are only and one there and pin DVDD, the voltage on the capacitors as required and 5v
Disagree, if this panel mode - as You wrote above - is AT070TN92 then is required give all voltages from control board, including positive and negative switch power. No builtin DC-DC converters inside this LCD model.
I see beside ZIF socket two chokes - typical LCD power circuits. If caps voltages was 5V - my guess are wrong - converters not working properly.
Also I think that dc dc converter does not work .but I have to help indentificare w373 component that I believe to serve the powers that are not there for the proper functioning of lcd.io modify the picture so of track you where and what and connected around him so can you help me to buy component corretto.vi thank everyone that I was aiutanto and ask you to help me again why this repair and for my station saldande for bGA and without the lCD is useless. Help me
HOW TO GET PICTURE IN POST # 8 I GAVE POWER SUPPLY WITH BENCH ON PIN 43 WHY HAVE VOLTAGE TOO LOW IN COMPARISON AS REQUIRED IN ACCORDANCE WITH ME THE PROBLEM IS WORKING OUT IF YOU CAN UNDERSTAND WHICH COMPONENT AND W373
That is TPS61040 (400mA out) or TPS61041 (250mA out). See datasheet in attachment and compare pinout.
This IC is not logic element but integrated DC-DC converter.
Giving external power on AVDD without proper gate on and gate off voltages You will killing LCD, refer to LCD datasheet and powering sequence.
With China components markings have huge differencies. This maybe "replacement" for part from familiar producer, and different marking for own purposes not matching to global rules.
Of course passives were checked before replacing IC. All diodes around are very important.
AVDD present? If yes what voltage. Should be 9,5V according feedback divider.
First thing is make converter running and obtain good AVDD. Shorted or broken boost diode or some in cascade will prevent this one from working. When AVDD will be OK then probably gate voltages too.
Use commas please, I do not understand above phrase.
those with very large voltage 6.5 now
I think so 6,5V is AVDD what I ask, "very large" what? resistor size, voltage?
If AVDD is 6,5V it's good news - converter is running but not working properly.
Read voltage on Vfb (pin 3). When this is 1,233V then feedback divider resistors must be corrected, when is below 1,233V converter works, but maybe some shorted diode or capacitor in cascade multiplier, at last - too weak IC and should be replaced to TPS61040. (I don't think so, but is possible).
You are electronic specialist, calculate output voltage when reference is 1,233V.
Divider current is: 1,233V / 1500Ω = 0,822mA
Upper resistor voltage is: 0,0822mA * 10000Ω = 8,22V
Total voltage on divider is: 8,22V + 1,233V = 9,453V
Assuming above calculation lower resistor must be 1500Ω.
This is base output for powering LCD - AVDD, gate voltages are produced on additional cascades and no matter yet. We must obtain stable AVDD first.
I did not understand where I have to control the voltage, and if the diodes wk wb and the voltage and:
wk 6,33v instead of diode wb -6.90.
LCD and connected.
I can say that now the display and ok but it's just that the colors are not good and a little bit, certainly as we increase the voltage you get the right color, tell me things I have to check yet?
Next step: check carefully all elements descripted on above photo as "Cascade multiplier for VGH" (diodes and capacitors). Parts in SOT23 are two Shottky diodes connected in series:
Final step: When You absolutely sure all above parts checked and good, replace IC to TPS61040.
Note: IC version was got according to calculated switch current.
Assuming: Inductor L=22µH. Voltage U=5V. Switching frequency 1MHz. Pulse max. time t=1µs. Maximum current should be 0,227A.
There is one trick - this converter maybe runing in continuous current mode, where inductor and switch current may exceed calculated for single pulse event.
From datasheet similiar LCD AT070TN01 reading maximum power consumption:
IDD = 30mA, IGH = 0,5mA, IGL = 1,5mA. This info maybe helpful.
Now the display and replaced diode wk ok, thank you for the great help you gave me. Now I would like to ask another for help if you can always concerns on the same card, as mentioned earlier this is a board for soldering station BGA rework model KIDI r450 and thanks to you and taken to work but yet another problem the temperature not ok I have normal 27 degrees but I see 57 of each probe thermocouple type k. And I'm wondering how I can fix this problem I've already checked all the resistors and are ok. I am attaching a photo
Add that each thermocouple is connected via aqw214e
then there are two other components that are also connected C8051F330 and other cs1180 and tomorrow provider and make a small diagram of connections