Acer AL2416W -- Backlight goes out

[budm]

Re: Acer AL2416W -- Backlight goes out

Looking at the MOSFET with the big tab up, the left pin is Gate, the middle pin (which is tied to the big tab, the middle pin may be trimmed off) is the Drain, the right pin is the Source. Since we are look for low resistance reading, set the meter to Ohm mode (2K) then check the resistance between S and D (which is the commonly failed mode) and report the readings. Next will be between G and S, then G and D, report the readings. Make sure to tell us (in case your meter only allow Auto-range) if the reading is in Ohm, K Ohm, or M Ohm.

[rogebe]

Re: Acer AL2416W -- Backlight goes out

Hello

Excuse me for the delay.

I made the measures with meter in K ohm

Here are the results :

Q4
SD=.002
GS=.021
GD=.023

Q6
SD=.000
GS=.097
GD=.097


Q5
SD=1
GS=1
GD=1

Q6
SD=1
GS=1
GD=1

Have you an idea ?

Thank's for you answer.

Nice day for you.

[budm]

Re: Acer AL2416W -- Backlight goes out

Remove Q4, Q6, then measure the resistance again, so far they look bad.

[rogebe]

Re: Acer AL2416W -- Backlight goes out

Hello

It is difficult to unsolder its mosfets.

I could unsolder pin of the S and G.

Measurements are approximatively the same one.

I think that they should be changed.

The question is which equivalence and how to unsolder D ?

Thank you for your answer

[budm]

Re: Acer AL2416W -- Backlight goes out

What are the numbers on the body? To remove the MOSFET, I cut the two small legs, then I added more solder to the tab then twist the body with small plier, I ue 60W Iron with large tip (3mm).

[rogebe]

Re: Acer AL2416W -- Backlight goes out

Hello

Q6 = P5504EDG
Q4 = P2804BDG

I try your tip

Thank you

[rogebe]

Re: Acer AL2416W -- Backlight goes out

It's OK, i can remove the two fets.

I add more solder ant twist the body.

It remains only to replace

[rogebe]

Re: Acer AL2416W -- Backlight goes out

Must not forget that F1 is blown.
I need to replace it with what ?

Thank you for your help !

[budm]

Re: Acer AL2416W -- Backlight goes out

'W' per BOURNS fuse spec, it is 4A. I cannot tell the dimension from the picture, you have to measure it.

[rogebe]

Re: Acer AL2416W -- Backlight goes out

I is most likely a M.
It measures 3 mm by 1.6 mm.

Does it give guidance?

[budm]

Re: Acer AL2416W -- Backlight goes out

Then that will be 1206, see the PDF.
1.5A is too low for that power section. I would say 3~4A range, you can put DMM in DC A mode to measure the current at max lamp brightness, then multiply by 2.

[rogebe]

Re: Acer AL2416W -- Backlight goes out

Well I'm going on SF-1206F400 but in first time i'll try to put a 4A fuse weld on F1

And for the mosfets ?

Q6 = P5504EDG
Q4 = P2804BDG

Thank's for all informations.

[budm]

Re: Acer AL2416W -- Backlight goes out

P5504 SPEC:

P2804 SPEC:

You can get both of them from EBAY.

[rogebe]

Re: Acer AL2416W -- Backlight goes out

Okay,

Thank you Budm

I'll change the mosfets, caps and fuse.

I'll keep you current after.

Good day.

[rogebe]

Re: Acer AL2416W -- Backlight goes out

Hello budm,

As expected, I changed mosfets, caps ...

It seems OK and the screen works correctly

A big thank you for your help.

But I still need you.

Could you give me somme ideas for this problem :

https://www.badcaps.net/forum/showthread.php?t=36826

Thank you for your answers and for your help.

Good day

RGB

[budm]

Re: Acer AL2416W -- Backlight goes out

OK, I will try not to forget to look at that thread to see what is going on.

[rogebe]

Re: Acer AL2416W -- Backlight goes out

Thank you budm, I do not know how to take myself with these wiewsonic.

I am already satisfied to have been able to run the AL2416W.

Good day.