Fixing an Acer AL2216W LCD Monitor (Delta DAC-19M010 power supply, bad caps)

There are several dozen of this model of monitor at my work since last year or so; the other day I found one on top of the dead electronics plunder pile recycling bin, looking brand new. Googling the model # and terms such as “problems” or “repair” or “won’t turn on” revealed pages of discussion on the badcaps.net forums: it seems this model of monitor is yet another victim of the bad capacitor plague that somehow continues to sweep the electronics world. Upon opening the monitor, this suspicion was confirmed by several visibly bulging capacitors in the low-voltage section of the power supply.

Probable Symptoms:

  • Monitor won’t turn on, no apparent power, black screen
  • Blinking power LED
  • Turns on but shuts itself off without warning*

Note: This power supply board (or very similar model) appears to be used in a variety of monitors from different manufacturers. Depending on which one you have, your symptoms may differ to what I have observed on the AL2216W. In particular, the monitor may simply not turn on (too-low logic voltage or software-controlled shutdown), may blink its power LED to indicate a fault, or may turn on for a few seconds and switch off again. In my case, the monitor showed absolutely no external signs of life (power LED dark and no response to the power switch), but a very brief flash of the backlight could be seen just as the unit was unplugged, confirming it did indeed have power but “chose” not to switch on (likely as a safety feature).

Obligatory Butt Covering Warnings

This is a wall-powered electronic gadget. Opening it and poking around inside carries a small, but non-zero, risk of electric shock even when unplugged. (There is a 100K bleeder resistor across the mains filter cap, but this could fail.) For your safety, wait at least one full minute after unplug to go near the supply board, and use a screwdriver with an insulated handle to short across the leads of the filter cap to be sure it is discharged. If you see a fat spark and blinding flash of light, the safety bleeder resistor has probably failed, and you might want to reconsider poking around in here.

(Opening it and poking around inside while it’s plugged in carries a guarantee of electric shock, just FYI.)

Disassembly

This is fairly straightforward. Pop off the plastic cover hiding the screws that attach the base. Unscrew them and any other visible screws, then carefully pry at the seam where the two halves of the monitor “shell” come together. Once inside, more screws. Note that to get the final metal shields off, the backlight connectors and the ribbon cable to the button panel must be disconnected, then the scew-in posts for the video connectors and two screws concealed in the mains cord socket must be removed.

What’s inside?

Surprisingly little, it turns out. There is one large power supply board (made by Delta Electronics, Inc.) and a much smaller display controller board (marked A220Z1-Z01-H-S6) with only two highly-integrated Realtek ICs and some discrete components. My educated guess is that the controller boards are very unlikely to fail, so start by looking at the Delta board.

Fault Finding

By all accounts, bad capacitors are usually the underlying cause of these problems. Due either to being under-rated or a sordid tale of corporate espionage (see Wikipedia link above), the capacitors will gradually vaporize their electrolyte (and sometimes not so gradually, with a bang) until they can no longer perform their capacitorly duties, causing the monitor to go haywire.

First, inspect all the electrolytic (“tin-can”) capacitors for visible problems. Their tops normally have a score pattern on them, but should otherwise be flat. They should not bulge upward, even a little. Visible bulging, ruptured tops or signs of leakage (e.g. brown goo around the top or seams) are sure signs they need replacing. Note that failed or failing caps will not always show visible signs.

On the Delta DAC-19M010 board, things are divided up into 3 logical sections: the bottom half is a switching power supply that steps your 120/240V wall power down to a 13.8V and 5V rail. Roughly speaking, everything to the left of the large center transformer is its primary (high-voltage) side, and everything to the right is the low-voltage secondary side (the high side may also be marked off by cutouts and/or a line on the underside of the board). The upper half of the board (more or less) is the backlight inverter, with another large transformer to step this low voltage up to the 1kV or so needed to feed the CCFL backlights.

I’m sure you noticed the large, high voltage cap on the high side, right near where the power cord plugs in. You did short it, right? This is the one that can make your skeleton glow even if the monitor is unplugged. Luckily, consensus from the internet is that this filter cap on the primary side rarely fails, so unless it is showing visible signs you can probably leave it alone.

There are seven electrolytic caps on the low-voltage side, all of which should be replaced if you even slightly suspect a capacitor problem. (Technically, the topmost one connects to the backlight inverter, but you should change it anyway.) On my monitor, the 13.8V rail read a tad high (14.x) and the 5V rail showed only 4.1V. There is likely an undervoltage lockout circuit on the controller that prevents operation at this voltage, although there may have been significant voltage ripple due to the bad caps that was resetting or otherwise fouling up the logic directly.

Collateral Damage

With the caps replaced, it’s a good idea to check for any obvious collateral damage. There are several surface-mount fuses (denoted Fxxx) on the bottom of the board which might have been affected (zero-ohm resistors may have been stuffed in place of some fuses; check these too). After you triple-check that the mains filter cap is discharged, also check the through-hole fusible resistor to the immediate left (high voltage side) of the switching transformer. There is also a surface-mount fuse on the controller board near the power entry connector.

Cap List

Here are suitable replacement parts currently available on Digikey. Be careful when removing the old ones, as some of them are near very brittle powdered-core inductors and tacked down with some kind of glue. Note, one of the parts below has a higher voltage rating than the original (this is OK).

Quantity Part# Value Lead Spacing Height
2x 565-1546-ND (220u/25V) 3.50mm 11.5mm
1x 338-2342-ND (2200u/10V) 5.00mm 21.00mm
3x 493-1065-ND (1000uF/25V) 5.00mm 20.00mm
1x 565-1550-ND (470uF / 25V) 3.50mm 20.00mm

* Note, if the screen’s backlight cuts out (often after a couple seconds) but the monitor appears to remain powered, the fault is most likely in the backlights or backlight inverter section of the power supply board, not the low-voltage section. You can confirm whether the entire system or only the backlight has shut off by holding a strong flashlight directly against the screen while a valid video signal is present – if you can see the image around the edges of the flashlight, the low-voltage supply and controller board are probably OK. Replacing C204 MAY solve it, but otherwise, fixing backlight issues is a whole different animal, which I don’t cover here. You MAY be able to identify a single dud tube by unplugging one at a time (WITH THE MONITOR UNPLUGGED!!!) and testing the monitor, but this is not 100% reliable (some inverter circuits will detect a single “open” (e.g. unplugged) tube and shut down anyway).

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28 Responses to “Fixing an Acer AL2216W LCD Monitor (Delta DAC-19M010 power supply, bad caps)”

  1. paul says:

    i spilled a drink on the front buttons on my same acer , i returned to the room it smoked a bit and i ran to unplug it . do you know the part number i should be tracking down and if it is in other acer models .
    thanks again paul

  2. Vikash says:

    Thank you very much for the information. I have a Viewsonic monitor with the same Delta board and several of the caps are bulging.
    It seems Delta is responsible for likely tens of thousands of otherwise good monitors ending up in landfills. Somebody should class action them.

  3. NCKnight says:

    your info was so helpful i had several bulging Caps – not sure if any other problems but will definitely replace the Caps – my monitor would come up and stay on as long as i didn’t turn it back off over 13 hours or more but only after hitting the power button many time to watch the ACER Logo appear and disappear over and over till the screen comes up (about 5 minutes w/multiple button pushing)- but your info was great and also sad for the quality of the Caps being used in these monitors – customers should send in complaints
    thanks again

  4. ummmm says:

    u got this WRONG !!!!!

    should be 2 of the 1000’s and 3 of the 220’s

  5. ummmm says:

    and the 2200 and the 470 probably are just fine

  6. ummmm says:

    and the part numbers u show are for capacitors that are..on average….20% larger in physical diameter than the stock ones

  7. ummmm says:

    10mm vs 8mm

  8. Tim says:

    @”Ummm”… these are suitable values for this board, I have the proof downstairs :-) The part diameters may not exactly match, but will fit in place of the originals (some of the “exact” size matches were out of stock when I checked, or had different voltage ratings, etc.). The critical physical parameter is the lead pitch, which is an exact match in all of the listed parts.

    As for your claim of wrong values (uF), not sure what you’re on about. Do you have the exact same board? There are many similar models. They may have substituted semi-arbitrarily for non-critical values too.

  9. Keeno71 says:

    Hi there great information, thankyou.
    My question is .On the underside of the PCB what is the value of the resistor R106. On my PCB bad caps have lead to the destruction of r106, I can only read the first to digits, (1-0-blister-burn), is it a,1k-ohm, 100-ohm, or other. My 5V rail is spot on, but the 13.8Vdc is measured at 14.2Vdc. The Lm317 seems to be regulating this rail. I’m using a 1k for R106 at the moment, but I would like to be sure it is correct as this is on the input side of the regulator and I don’t want to starve it of it’s input voltage by using a too high resistor.

  10. Keeno71 says:

    oh, all Caps have been replaced with the Low ESR variety at slightly higher Voltage tolerances where ever possible.
    ==for example 10v is now 16v and the main Inverter cap 470uf is 35V,(working voltage.). The cap-1000uf and Ind-3R3 combination are above,( and linked to), “R106” and a diode,(ZD100).

  11. MT says:

    Thanks for the help

  12. Roger Sinclair Jr IV says:

    This doesn’t look at all like an easy fix, and I have zero experience with messing around with circuit boards. God dammit.

  13. Darrell says:

    @Roger Sinclair – You can simply replace the whole board for $12.95 plus shipping & your time & effort.

    http://lcdalternatives.com/Acer-AL2216-C214551.aspx?sid=19447

  14. Anonymous says:

    @Darrel lcdalternative you list are KITS not boards

  15. Bruce says:

    Thx for posting this. I have the same monitor with a different power supply. (Make) my monitor comes on all white, I assume the video board is not getting the correct voltage’s as there is only two conection of the eight with 5,1 volts coming form the Ps. do you know if there should be more?

    Best regards
    bruce

  16. Paymon says:

    Hello,
    Great info.
    I have a dual monitor setup and apparently AL2032W Acer monitor (according to display in control panel) is the one I have issues with. The screen suddenly disappeared. Since then either the acer logo shows up upon pressing the power button or the screen just appears for less than a second upon disturbing the standby mode and then goes away. I checked the graphic card, if I connect my TV to the same port of my Acer it works fine. Then I assume it should be one of the caps?! I just want to know if I am on the right track before opening the monitor. Thanks for your attention.

  17. Danny says:

    Thank you so much for this guide! I repaired my Acer AL2216W using this guide – though it was a DAC 19M009 power supply board, the capacitors in use (and they were all leaking or bulging) were the same. Previously, it had been powering on, showing the Acer logo, and shutting off repeatedly until eventually it would work, usually after ~30 minutes or more of trying to get it to turn on. Now, it powers on perfectly fine every time!

    A note to anyone who finds this guide in the future: When opening the plastic case around the monitor, several small plastic tabs around the edge of the inside broke off. However, this didn’t affect how the monitor looks or stays together when reassembled, so I wouldn’t worry if the same happens to you.

  18. WNM says:

    “Darrell says:
    9/22/2012 at 9:58 am
    @Roger Sinclair – You can simply replace the whole board for $12.95 plus shipping & your time & effort.

    http://lcdalternatives.com/Acer-AL2216-C214551.aspx?sid=19447

    That isn’t the “whole board” it’s just a kit of a handful of capacitors. That doesn’t guarantee anything. I replaced faulty capacitors in my monitor with quality ones and it worked great – for a month.
    Now it has a completely different problem going on with it.

  19. Dheepak says:

    hey guys i replaced all the electrolytic capacitors. but my screen still flashes(i.e) operates for a while and turns off and on at its wish. I have lenovo monitor with two dc out for monitor from power board

  20. Russ says:

    Have a Viewsonic with the DAC-19m010, has the blinking power light problem. All caps except the filter cap replaced with new low esr types (Digikey Panasonics, not crap from some of the ebay sellers). While probing to check for 13.8V and 5 volts I slipped and shorted the 5 to ground. Now I have a dead surface mount fuse F101. Unable to see the letter designation on the fuse. F100 shows an “S” but not sure if it’s the same kind of fuse as F101 that is blown. Anyone know what the value/type that F101 was/is?

  21. Branjo says:

    Just done this on two AL2216W’s and after 20 minutes on each monitor they are back in action!

    Great money saver, thanks so much for the info I needed.

  22. TM says:

    My friend i thank thee for shaving another Acer screen from the heap, took me 4 minutes to fix my screen.

    A 10/10 nothing less

  23. Jim Nelson says:

    Thanks for the support. Managed to replace 7 caps on the lo-vo side and the monitor fired right up, after previously having taken longer and longer (> 1 h) to come up and finally never coming up at all. Took, not 4 or 20 minutes, but a couple of hours as it was my first time and I didn’t want to mess it up, but apparently all the solder joints are solid and no leads got shorted.

  24. Joel T. Pagala says:

    thanks for the info,, this is really great,,,

  25. Amol says:

    I Am Amol i am facing problem for Monitor display r flicker i found that mointer inverter Red Wire tuch my multimeter display working fine but his remove again diplay r flicker pls help me out off this switchvation

  26. Caleb says:

    @Russ F101 on my Delta DAC-19M020 Rev 00A is marked with a W, mine is also blown.

  27. askar says:

    acer LCD moniter P195HQ power pcb cercut

  28. Repete says:

    µF is the abbreviation for micro farad, you can get the symbol using the Alt+230 on the numeric keypad.
    HTH

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