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Old 03-31-2017, 07:49 PM   #1
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Default V7 D22W12 Monitor 2 seconds to black ILPI-033 Caps

Hey there guys, truly hidden gem here on the internet. Not sure how 'hidden' it is, but I just hadn't stumbled upon this forum yet. Sorry, that could've gone in my intro post.

Anyhow, I have a V7 D22W12 LCD monitor which I'm pretty sure just needs a little TLC, and it may become usable again. Once connected, it will display a desktop for ~2 seconds, then go blank. My internet research on such matters suggests fried capacitors. I have fixed circuit boards previously with my tremor riddled hands, and figured, why not give this one a shot?

I pulled apart the LCD down to the power inverter board. I do indeed see one 1000uf 25v cap with a buldging lid and white goo. Another blue coin shaped cap has similar goo. Interestingly, every pic I've found of this board shows that blue coin shaped cap with white goo. For instance:

https://m.aliexpress.com/item/32274872296.html

Dead center of the pic is the white goo on the cap. Directly left of that behind the heatsink is a taller, green cap. That is the bludging goo covered cap on my board. That pic actually appears to show a bit of white goo too, perhaps the goo is normal?

If the goo is normal, then maybe I just need to try to replace the 1000uF 25v cap. Without a RadioShak nearby, which website to you guys favor for caps?

Assuming the goo is abnormal, could somebody help me identify that blue coin shaped cap? My eyes can't make out the TINY writing on it.

ILPI-033 1
REV: C
2008/05/15 is the board identification.

The caps in question are C815 (bludging tall green one) and C823-1 (round blue coin one)

I found somebody else refering to the ILPI-033, and thought the PDF there might help, but I couldn't make heads or tails of it.

http://www.badcaps.net/forum/showthr...light=ilpi-033
Post 9 & 12

I can submit pics if needed. But the top pic is my board.

Thanks in advance for your help.
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Old 04-01-2017, 11:52 AM   #2
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Default Re: V7 D22W12 Monitor 2 seconds to black ILPI-033 Caps

Yep, please post picture of your power board.
Anyway, this issue is indicating a backlight failure : either the CCFL themselves or the inverter. See the sticky thread http://www.badcaps.net/forum/showthread.php?t=10419

The white stuff on the caps is glue, nothing wrong with it as long as it is not discolored. If it is, remove it.
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Old 04-01-2017, 06:14 PM   #3
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Default Re: V7 D22W12 Monitor 2 seconds to black ILPI-033 Caps

I'm new to LCD repair, so CCFL is like the CFLs that were supposed to replace incandescents, but didn't work well? I take it that is the light source behind the LC's?

The screen does work perfectly for a moment, so they clearly light, but by reading the sticky, it seems like one of the bulbs may be overtaxing the circuits, and you elimate that possiblity by swapping in known good CCFLs?

Forgive me, away from keyboard, in WVA...On a phone, so typing is exhasiting.

Anyhow, I'm glad to hear the white is merely glue. Several pics of same board show same spots of white goo. Anyhow, visually I only noticed the one cap that appears to have bulged the lid up. Also not terribly familiar with replacing soldered bits. Will I need to desolder, if so is the braided wicks the way to go?

Will post pics when I get home tomorrow. Thanks again for the info.
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Old 04-01-2017, 08:36 PM   #4
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Default Re: V7 D22W12 Monitor 2 seconds to black ILPI-033 Caps

https://youtu.be/umsr1suOZ28

Just stumbled upon this video while educating myself on cap replacement on PCBs. Exact same LCD, exact same failed cap. Looks like a different brand cap, but same location.
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Old 04-02-2017, 05:57 AM   #5
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Default Re: V7 D22W12 Monitor 2 seconds to black ILPI-033 Caps

Chances are this is indeed the problem.
This should be easy to replace, you don't even need to remove the solder (but it is often better). Add some fresh solder on the pins of the capacitor on the back of the board, heat them up and gently pull the cap. While you're still heating the pads, insert the new capacitor and add some fresh solder after the cap is in place.
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Old 04-05-2017, 06:37 PM   #6
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Default Re: V7 D22W12 Monitor 2 seconds to black ILPI-033 Caps

Update: I've got caps coming in the mail tomorrow, so the monitor will go under the knife in the evening. Hopefully post a 'Wahoo' post shortly after.

I know these pics suck, I've seen the suggestions of taking pics during full sunlight, but I have NOT found anytime during the day to do such a thing.
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Old 04-06-2017, 07:41 PM   #7
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Default Re: V7 D22W12 Monitor 2 seconds to black ILPI-033 Caps

Oh BadCaps.net forum, how I've failed you! I finally got my replacement caps in the mail today. Did some pretty novice cap replacement, but I did manage to replace the obviously bad cap. Reassembled the screen, hung it on the wall...


...and...


I haven't a stinking video cable to test it with. The monitor has VGA or DVI inputs. I've got HDMI cables, but no simple VGA or DVI. The CRT that I'm using to type this sob story has a fixed in place VGA cable. It cannot be removed from the back of the screen.

I can confirm the monitor 'boots', says 'No Input Signal' then switches to standby, and the green LED turns orange. Pretty sure it did that at least before. So no clue if I'm good or not. Will have to steal a VGA cable from work tomorrow to test it out. So frustrating!
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Old 04-07-2017, 05:36 AM   #8
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Default Re: V7 D22W12 Monitor 2 seconds to black ILPI-033 Caps

If you've got a DVI to HDMI adapter, it may work if you use it on the monitor's side.
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Old 04-07-2017, 05:48 AM   #9
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Default Re: V7 D22W12 Monitor 2 seconds to black ILPI-033 Caps

Success! I was able to obtain an VGA cable early this morning from an undisclosed source. Monitor is looking good.

(Picture was taken before color adjustment. The pinks are white after adjustment)
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Old 01-10-2022, 04:20 AM   #10
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Default Re: V7 D22W12 Monitor 2 seconds to black ILPI-033 Caps

Kindly, could you tell me what is the value of the R506 and R525 resistor? I can't understand the colors.S20220110_0002.jpg

S20220110_0001.jpg
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Old 01-10-2022, 12:04 PM   #11
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Default Re: V7 D22W12 Monitor 2 seconds to black ILPI-033 Caps

R525 = 3megΩ 5%, Can't make out R506 but it looks the same. These resistors are also rated 3KV
It looks like just the outer coating is cracked, I suspect the resistors are ok.

Last edited by R_J; 01-10-2022 at 12:41 PM..
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Old 01-10-2022, 02:39 PM   #12
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Default Re: V7 D22W12 Monitor 2 seconds to black ILPI-033 Caps

However I discovered that one of the inverter stages is not working, and probably after a few seconds it goes into protection and the black screen appears.What should i check?
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Old 01-10-2022, 03:07 PM   #13
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Default Re: V7 D22W12 Monitor 2 seconds to black ILPI-033 Caps

Check the resistance of the secondary windings on the t501 and T502 transformers and see if they are the same, or is T502 higher or lower in resistance. Try switching the ccfl lamps from CN503 and CN504 to CN501 and CN502 to see if the shutdown is caused by a bad ccfl.
Also inspect the 2 blue ceramic caps in the output, on some models they can be bad and short when there is high voltage present.

Last edited by R_J; 01-10-2022 at 03:14 PM..
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Old 01-11-2022, 01:17 AM   #14
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Default Re: V7 D22W12 Monitor 2 seconds to black ILPI-033 Caps

Is there some kind of tutorial, to explain the basics of how LCD computer displays work?
I want to learn what are the basics sections of the power supply board. I know most displays have two boards inside (or three if you count the board with command buttons).
One is the power supply board (mostly yellow color) and it has Power AC input part with diode bridge rectifier and big electrolytic capacitor (400 V DC), and then there is a part to produce high voltage (amplitude and frequency) to produce backlight.
I know that most computer monitors have 5V and 12V on this board. I would like to learn the basic sections of this power supply board since most of the time, the problems are located here.

Ago$tino placed the nice schematics. It would be good if someone recommend appropriate tutorial if there is one about the computer LCD/LED monitors.
Most I found on youtube explain how to replace caps, but I'd like to learn how this is structured.

Thank you.
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Old 01-12-2022, 03:56 AM   #15
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Default Re: V7 D22W12 Monitor 2 seconds to black ILPI-033 Caps

Ok, I checked the transformers and they are efficient, same homs, then I checked the 4 blue ceramic capacitors and strangely the tester does not read them. They are the C506, C509, C523 and C528. All four are not read. I've tried other capacitors I have in stock and the meter reads them all.
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Old 01-12-2022, 10:38 AM   #16
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Default Re: V7 D22W12 Monitor 2 seconds to black ILPI-033 Caps

The capacitors are likely good, the value is too low (3pf) for those meters to check them. The transformers seem to be ok as well.

Last edited by R_J; 01-12-2022 at 10:41 AM..
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Old 01-13-2022, 03:32 AM   #17
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Default Re: V7 D22W12 Monitor 2 seconds to black ILPI-033 Caps

no way! I can't get it to work. I ordered a led conversion kit. Then someone will give me a hand to identify on the diagram where to take the voltage to power the LED bar driver?
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