Acer AL1717F blue led does not turn on

[mikey5791]

Re: Acer AL1717F blue led does not turn on

Hi forum friends,

Anyone can help me on this?

[mikey5791]

Re: Acer AL1717F blue led does not turn on

It is necessary to check or change all the capacitors in the 5 volt / 3.3 volt / 1.8 volt circuits for new ones . These voltages should be exactly the same and without AC ripples

Hi,

May i know which capacitors are for the 5 volt, 3.3 volt and 1.8 volt circuits? Can you kindly guide me how to verify which caps are for certain circuit because i totally have no knowledge on this. For your info, i do not have access to an oscilloscope and may not be able to check on the AC ripples. Is there another way to check AC ripple?

Btw, earlier i had desoldered off board those medium size brown Suscon caps marked at c809, c812, c808, c826, c810 and c522 at power supply board. I used an esr meter and tested all those 6 caps esr read 0.00(low good esr) and uf reading do not exceed more than 5% of what was printed on caps.
Glad that you can offer your help on reviving this monitor.

[kasfamily]

Re: Acer AL1717F blue led does not turn on

It is necessary to check or change all the capacitors in the 5 volt / 3.3 volt / 1.8 volt circuits for new ones . These voltages should be exactly the same and without AC ripples

[mikey5791]

Re: Acer AL1717F blue led does not turn on

The 3-pin U101 and U102 must have 5 volts ! The 4-pin U101 must have 3.3 volts ! The 4-pin U102 must have a voltage of 1.8 volts. I repeat the question-where did the 11 volts on this board come from ?

Yesterday night i redo the voltage test, this time I test it twice with following results:
Sorry for the misleading results of 11 volts earlier on.

U101 pin 2=3.10
pin 3=4.70
pin 4=3.10

U102 pin 2=1.60
pin 3=4.70
pin 4=1.60

[kasfamily]

Re: Acer AL1717F blue led does not turn on

The 3-pin U101 and U102 must have 5 volts ! The 4-pin U101 must have 3.3 volts ! The 4-pin U102 must have a voltage of 1.8 volts. I repeat the question-where did the 11 volts on this board come from ?

[mikey5791]

Re: Acer AL1717F blue led does not turn on

on a small board (logical with a processor), where did the voltage of 11 volts come from? It only supplies 5 volts ! What is the marking on the u101 and u102 ?

u101=ld1117a
l33auc

u102= a1
as1117l-18
b0703 b6

[kasfamily]

Re: Acer AL1717F blue led does not turn on

On a small board (logical with a processor), where did the voltage of 11 volts come from? It only supplies 5 volts ! What is the marking on the U101 and U102 ?

[mikey5791]

Re: Acer AL1717F blue led does not turn on

need a clear photo of the parts in the red circle, so that the marking can be read

Attached a clear photo of your request.
Appreciate your kind assistance.

[kasfamily]

Re: Acer AL1717F blue led does not turn on

need a clear photo of the parts in the red circle, so that the marking can be read

[mikey5791]

Re: Acer AL1717F blue led does not turn on

How many volts per pins u101 and u102

U101 pin 2= 6.12v
pin 3=11.05v
pin 4= 5.14v

U102 pin 2= 3.18v
pin 3=10.69v
pin 4= 3.31v

Both pins 1 reads 0v

[kasfamily]

Re: Acer AL1717F blue led does not turn on

How many volts per pins u101 and u102

[mikey5791]

Re: Acer AL1717F blue led does not turn on

Sorry, I said it badly, you need a clear photo of only a small board ( logical, with a processor )

Is ok, no problem .
Attached a clear photo of small board (logical with a processor).
Glad that you can assist.

[kasfamily]

Re: Acer AL1717F blue led does not turn on

Sorry, I said it badly, you need a clear photo of only a small board ( logical, with a processor )

[mikey5791]

Re: Acer AL1717F blue led does not turn on

Show a photo of the motherboard from the parts side

Attached the photo of main board and logic board from the parts side.

[kasfamily]

Re: Acer AL1717F blue led does not turn on

Show a photo of the motherboard from the parts side

[mikey5791]

Re: Acer AL1717F blue led does not turn on

Hi kasfamily,

Thanks for reply.
CN801 pin 4(on/off)=0.00vdc
L802=13.9vdc

Glad if you can assist me further in bringing this monitor to life again.

[kasfamily]

Re: Acer AL1717F blue led does not turn on

Hi!
How many volts when turned on
CN801 pin4 ?
L802 ?

[mikey5791]

Hi all,

I have this Acer AL1717 F working lcd monitor, but yesterday the blue led light on the front switch doen not turn on and thus no display on screen. Upon opening the outer casing, and looking at overall board (image 112637), i do not see any burned parts or bulge caps. Fuse T2A measured with continuity.
The main caps has around 340vdc. Tha main board(image 113242) has vcc 5vdc on pin 1&2 on the red wire. I would like to understand what is going bad and to request for any guide and kind help to replace or repair the bad faulty part instead of throwing this monitor to dump. Any generous assistance in the right direction is highly appreciated.