Acer X223W is black without led

[fred69]

Hello,

My problem is the fallowing.
My acer screen X223w worked very well, I turned it off with the front button, two hours after I turned it on with the front button and nothing happens. Now I have no led to the front and the screen stays black.

I opened the screen to study the problem (cf picture)

All fuses are OK
All capacitors are OK

On CN801
While off
1) 5.05v (VCC 5V)
2) 5.05v (VCC 5V)
3) 0V (GND)
4) 0V (GND)
5) 0.03V (on/off)

While on
1) 5.05v (VCC 5V)
2) 5.05v (VCC 5V)
3) 0V (GND)
4) 0V (GND)
5) 0,03V (on/off)

I think the problem is there, the pin on/off is always near 0V, even if I push on the ON/OFF button.

On the logic board, regulator at U106
Pin 1 reads 0 volts
Pin 2 reads 3.29 volts
Pin 3 reads 5 volts

On U501 and U502 (two n channel mosfets) there is always 17.8V

On the 16 pin IC, IC501 (OZ9938), pin2 (VDD) is correct (5V)
Pin 10 (ENAble) is always 0,05V, it's not correct

Have you any idea of the source of my problem?

Thanks

[selldoor]

Re: Acer X223W is black without led

Check if the on/off button is stuck - check the button board lead is plugged in.

If you hav a 3 volt cr2032 or 2x1.v volt batteries try jump starting it by applying 3v to the pin5 on/off

Also , nothing to do with your problem can you advise the colour of the rings on R816

[fred69]

Re: Acer X223W is black without led

Check if the on/off button is stuck - check the button board lead is plugged in.

The On/Off button is not stuck

If you hav a 3 volt cr2032 or 2x1.v volt batteries try jump starting it by applying 3v to the pin5 on/off

Yes it's a good idea, I will try this

The rings on R816 : brown, black, brown and gold. (100 ohms) it's ok.

[fred69]

Re: Acer X223W is black without led

Hi,

I connected a 3 volts batterie between the pin5 on/off and pin3 (0V) of CN801. Only the ground is welded and I establish the contact with the other side of the battery on pin 5 of CN801. The results are the following

Note : CCFL are removed

On IC501 (OZ9938):

Pin1: 0V (OFF) then 2,38V during ~3s (ON) then 0V (DRV1)
Pin2: 5V (OFF) (VDDA)
Pin3: 0V (OFF) then ~2,87V during ~3s (ON) then 0V (TIMER)
Pin4: 1,128V (OFF) then 1,131V during ~3s (ON) then 1,128V (DIM)
Pin5: 0V (OFF) then 0,01V during ~3s (ON) then 0V (ISEN)
Pin6: 0V (OFF) then 1,90V during ~3s (ON) then 0V (VSEN)
Pin7: 0,32V (OFF) then 0,43V during ~3s (ON) then 0,32V (OVPT)
Pin8: 0V (NC)
Pin9: 0V (NC)
Pin10: 0,04V (OFF) then 3,16V during ~3s (ON) then 0,04V (ENA) ON/OFF
Pin11: 0,76V (OFF) then 0,77V during ~3s (ON) then 0,76V (LCT)
Pin12: 5V (OFF) then 0V during ~3s (ON) then 0V (SSTCMP)
Pin13: 5,1V (OFF) then 1,15V during ~3s (ON) then 5,1V (CT)
Pin14: 5,1V (OFF) then 1,15V during ~3s (ON) then 5,1V (GNDA)
Pin15: 0V (OFF) then 2,35V during ~3s (ON) then 2,35V (DRV2)
Pin16: 0V (PGND)

I think the operation is normal now. According the datasheet of OZ9938
if a CCFL is removed or damaged during normal operation (this is my case, CCFL are removed), the voltage at SSTCMP (pin 12) rises
rapidly. When the voltage at SSTCMP reaches a threshold of approximately 2.5V, a current source charges the capacitor connected to TIMER
(pin 3). Once the voltage level at the TIMER pin reaches a threshold of approximately 3V, the drive outputs shut down and latch..

Next step : trying to connect lamps

[selldoor]

Re: Acer X223W is black without led

When you said the caps were good is that just a visual check?
If U106 is connected to C102 or C103 what voltage is on them?

[budm]

Re: Acer X223W is black without led

See my post #12 for the diagram of your power supply/inverter board. It uses the same board as used in Viewsonic VA2226W
https://www.badcaps.net/forum/showth...235#post303235

[fred69]

Re: Acer X223W is black without led

Hi,

Thank you for the service manual, is the same as mine indeed.
Now I can check the I/F board

[fred69]

Re: Acer X223W is black without led

Hi,

Thank you for the service manual, is the same as mine indeed.
Now I can check the I/F board

When I said the caps were good, I tested this caps
The voltage on C102 is 5,13V
The voltage on C103 is 3,29V

[fred69]

Re: Acer X223W is black without led

When you said the caps were good is that just a visual check?
If U106 is connected to C102 or C103 what voltage is on them?

When I said the caps were good, I tested this caps
The voltage on C102 is 5,13V
The voltage on C103 is 3,29V

[selldoor]

Re: Acer X223W is black without led

Next step : trying to connect lamps

Have you done that yet? do they come on when using the jumper battery

[fred69]

Re: Acer X223W is black without led

No, I have not yet done so. I think to do it this weekend at the latest

I checked my I/F board with the service manual file. Unfortunetly the card described in this document is not the same as mine. So I have some difficulties to understand how the voltage comes on CN801, from ON/OFF button.

Could you help me please ?

[selldoor]

Re: Acer X223W is black without led

Yes I looked at that decided might need to check Q102&Q105 then when I looked for them on your board they were not where they should have been.
What is the part number of your board?

Perhaps do a close up picture of the top left corner of the board not shadowed by the caps so we can see the traces. so we can trace back
from the pin.

[fred69]

Re: Acer X223W is black without led

LF board 490901300200R

[fred69]

Re: Acer X223W is black without led

Have you done that yet? do they come on when using the jumper battery

I tested using the jumper battery: the lamps work !
So the problem comes from either I/F board or settings card (with button).

I'd rather find failure but if I do not I think isolate the original ON/OFF button and the led and apply 3,2V taken somewhere on the circuit.

What do youi think about this ?

[budm]

Re: Acer X223W is black without led

never mind, it is answered in post14.
Did you download the service manual?
http://elektrotanya.com/?q=showresul...nitor&kat2=all

[selldoor]

Re: Acer X223W is black without led

I have looked at it - it is a different board again!

FRED69 are you sure your is the X223W model?


EDIT

Yes it probably is =shopjimmy has two different power supplys and two different main boards for the X223W

[fred69]

Re: Acer X223W is black without led

Hi

Budm thanks for your research, I already found this document and it' s not for my card like said Selldoor.

I believe the exact reference is x223wb, but I do not think it changes anything.
I find nothing with reference x223wb.

[budm]

Re: Acer X223W is black without led

Is there any number printed on the sticker or on the board (main board)?

[fred69]

Re: Acer X223W is black without led

Here is all the information I have

[selldoor]

Re: Acer X223W is black without led

I keep looking at this and go round in circles but never get back to the same place !!! is that possible??
The main board is also known as an ILIF-045
Shopjimmy then has 791031300011R and 791031300010R

But it doesnt say what they fit.

Searching ILIF-045 also bring up other sets which should have that board but when you get to the schematics it has a different board.

Perhaps someone might have better search skills?