Acer AL2416 AL2416W 24" 1920x1280 LCD Monitor

[kd5zmg]

Re: Acer AL2416 AL2416W 24" 1920x1280 LCD Monitor

That was very valuable information there. I think budm is onto the problem. I checked the caps you used and they are not low esr. You HAVE to use low esr caps in these units. That would explain why it worked, then shut down every 15 minutes. And after you replaced the 4 FETS. 2 1/2 hours.
The inferior caps possibly took out at least 1 of the FETS, and possibly a fuse is blown.

This is the way I would proceed with this repair....

1. Replace those caps with the high esr caps you have on order.
2. Now move on to testing the "M" smd fuses (should be 3 white ones)
3. Also test the (2) FDD4685 and the (2) FDD8451

Until that section is solid, there's no chance that it will work.

And yes, we REALLY could use those pictures of the inverter board.

Good luck! ~L-J-7~

The display would cut off every 15 min because I told the system to turn off both displays. I checked the fuses and I get continuity. I have the Low ESR Caps now. I will solder them in after my interview and dinner and will fire it back up to give you all the results. I am hoping these CDE caps are good enough quality to run this monitor for a while. I bought them from Mouser Electronics. Wish me luck.

[kd5zmg]

Re: Acer AL2416 AL2416W 24" 1920x1280 LCD Monitor

Ok,

here are my pics. Do the caps have to be 105C, or can I get away with the 85C caps that were sent to me?

In any case, I was not successful. I am getting the same result. Blank screen...

No logo even this time.

If I don't get new displays, I will try and get another inverter.

[budm]

Re: Acer AL2416 AL2416W 24" 1920x1280 LCD Monitor

So just to sure after the caps changed, do you still have the 24v on all the fuses and BL_ON signals?

[retiredcaps]

Re: Acer AL2416 AL2416W 24" 1920x1280 LCD Monitor

Do the caps have to be 105C, or can I get away with the 85C caps that were sent to me?

Some of those ICs can run very hot and using 85C caps means they won't last very long term. For now, they should suffice until you find root cause.

[Lumberjack777]

Re: Acer AL2416 AL2416W 24" 1920x1280 LCD Monitor

Nice pics. Excellent soldering by the way. Once I fixed that inverter board and used substitute FETS that I thought were equal to the originals. The monitor lasted 2 weeks. If the fuses are good, I'm suspecting the high esr caps may have blown one of the fets. You need to test those 4 FETS. I'm going to bow out and let the diagnostic pros, budm and retiredcaps guide you with any diagnostics. Check what budm said. And also check those 4 FETS. Since it worked and then burned out after 2 1/2 hours. I'm suspecting the problem is in the area of the repair. Also check all the plugin connections to make sure they are connected solid. We'll get there ~L-J-7~

[kd5zmg]

Re: Acer AL2416 AL2416W 24" 1920x1280 LCD Monitor

LJ7 Thank you for the compliment on the photos and soldering. I'm a bit rusty in my 40's.

I have more FETs, I can pull them off and try again.

First how should I test the FETs? Am I looking for a value rating or continuity?

[jetadm123]

Re: Acer AL2416 AL2416W 24" 1920x1280 LCD Monitor

May I suggest the following:

1) check to make sure that you installed your caps correctly and that there are no solder bridges causing a short.

2) verify that you are still getting 24VDC to the inverter board.

3) check again the 3 fuses on the inverter board for continuity.

4) check the mosfets using the guide here:

https://www.badcaps.net/forum/showthread.php?t=10419

[Lumberjack777]

Re: Acer AL2416 AL2416W 24" 1920x1280 LCD Monitor

LJ7 Thank you for the compliment on the photos and soldering. I'm a bit rusty in my 40's.

I have more FETs, I can pull them off and try again.

First how should I test the FETs? Am I looking for a value rating or continuity?

To test the FET's - post #19 from the excellent article from retiredcaps

https://www.badcaps.net/forum/showpo...4&postcount=19

[kd5zmg]

Re: Acer AL2416 AL2416W 24" 1920x1280 LCD Monitor

1. Caps are installed with the marking on the cap with the marking on the board, same way when I desoldered the original caps.
2. When the Green LED is on Voltage at F1, F2, F3 and the 2 blue coils at L1 and L2 read 23.97VDC and when the LED turns amber voltage drops to .54VDC
3. Fuse ratings with power on DMM set to 200Ohms is .89 Ohms per fuse
4. FETs readings with DMM set to 200 Ohms is OL, when I put it to MOhms setting I can read .1777. I hope my meter is not borked.

Only one I am not sure about is the FETs. I am still at a loss at this point.

[retiredcaps]

Re: Acer AL2416 AL2416W 24" 1920x1280 LCD Monitor

2. When the Green LED is on Voltage at F1, F2, F3 and the 2 blue coils at L1 and L2 read 23.97VDC and when the LED turns amber voltage drops to .54VDC

Hookup a working computer with your favourite wallpaper. What do you see?

[kd5zmg]

Re: Acer AL2416 AL2416W 24" 1920x1280 LCD Monitor

Nada, I am not seeing the Acer Logo anymore either, but I do see what appears to be lamp/backlight when the Green LED is on and it goes away when the LED turns Amber.

[jetadm123]

Re: Acer AL2416 AL2416W 24" 1920x1280 LCD Monitor

I remember that on of the AL2416W inverters I repaired, in my hurry to test it out, I plugged in the 6 ccfl connectors without paying attention. When I powered up the monitor, I got nothing. Upon further examination, in my hurry to install the plug into the connector, I accidentally bent one of the pins inside ccfl connector. I suggest you disconnect all the plugs and inspect for any bent pins and reseat each plug.

[kd5zmg]

Re: Acer AL2416 AL2416W 24" 1920x1280 LCD Monitor

ok, fingers crossed again. I found the my problem. It was the ribbon cable not plugged in, I am now running the AL2416W as my second screen for now. It looks good so far. I hope it works while I telework on Tuesday. If not I have a back up 20" to hold me over until I buy 2 new displays. I will report back if anything changes on the behavior of this display.

Thank you all for the responses and the help.

[budm]

Re: Acer AL2416 AL2416W 24" 1920x1280 LCD Monitor

So basically the low ESR type caps fixed the problem. I wonder the ESR of first set of caps you have replaced are.

[kd5zmg]

Re: Acer AL2416 AL2416W 24" 1920x1280 LCD Monitor

budm,

So far it appears as such that the Low ESR DID fix it, from what I can tell. It is still working right now. But the minute it stops I will post again. The screen appears to look clearer than the other screen too. Unfortunately I am not sure how to take a picture of the screens in action, otherwise I would take a picture to show comparison.

EDIT:

Looks like at 0625 this morning while messing with calibration settings for both displays the one I have been trying to fix went out again. Black screen no image, but still appears to be backlight. I took the display apart again and took measurements and voltage appears to be normal at the coils and the fuses. Only thing I can think of is the main board cap issue at this point. Unless the 85C Low ESR caps are not worthy enough. But like I said, I see backlight, just no image. I could have sworn that Acer replaced the Logic board, but I do know they replaced the LCD for sure.

[budm]

Re: Acer AL2416 AL2416W 24" 1920x1280 LCD Monitor

That sounds like the problem in the main board, especially if you try to run at full native resolution, it will draw more power. If you can lower the resolution and the pictures come back, then that is more likely to have poor filtering, poor regulation.

[sle118]

Re: Acer AL2416 AL2416W 24" 1920x1280 LCD Monitor

Thanks everyone that contributed to this thread. I wanted to share my story here.

After being purchased from Costco, my AL2416 had been used as my every day work monitor for several years, along with another 24" Dell.

The problems started with fume coming from the upper left corner of the monitor, and shortly after the left side was completely dim.

Measurements on the board revealed a shorted Q6, a blown F2 fuse and bulged C36, C38 caps.

I replaced all capacitors as well as
Fuse F2 (replaced with marking J)
Q4 P2804BDG
Q6 faulty P5504EDG
Q3 P2804BDG
Q5 P5504EDG

And a quick test shows the monitor is back to life. I will now have it turned on for a little while to see if it will hold well.

Otherwise, I saw some inverter board on eBay for $29 shipping included so I might just order one.

[budm]

Re: Acer AL2416 AL2416W 24" 1920x1280 LCD Monitor

sle118, I would replace ALL those caps (they are connected in parallel) on the inverter board.
https://www.badcaps.net/forum/showth...ghlight=al2416

[sle118]

Re: Acer AL2416 AL2416W 24" 1920x1280 LCD Monitor

sle118, I would replace ALL those caps (they are connected in parallel) on the inverter board.
https://www.badcaps.net/forum/showth...ghlight=al2416

Thanks for the advice, but as stated in my post, ALL of these caps WERE changed. The pictures show the board before the repair.

[budm]

Re: Acer AL2416 AL2416W 24" 1920x1280 LCD Monitor

Ok, I see, I just went by the pictures.