Lcd Monitor Flickers & Goes Black

wild1210 · Joined: Jul 30, 2007 Posts: 1

was lucky enough to fine this websight....helped out a lot ....
i see everone is haveing a hard time trying to remove the old capacitors
here a list of tools i bought a while back that might come in handy

1.45-Watt Desoldering Iron this helped me remove the solder with ease....
2.Kronus™ Helping Hands this helped me hold the board so i have to hands free to work with
3.Kronus 61-Piece Super Tool Kit i allready had this tool kit that has everthing i need for the job including a soldering iron ...there are cheaper tool kit just look around

the above shows the tool i have that made it easer to do the job for me

tool you will need
1.phillips screw driver
2.soldering iron
3.some type of tool tha remove solder
4.solder and flux
5.needle nose plyers

the helping hands and the desoldering iron are a PLUS for me ....made the job easer...holpe this helps out good luck

extremx · Joined: Aug 08, 2007 Posts: 1

Hey Guys

Thanks for all the advice. After reading through this forum i went to radio shack and bought the parts and had a guy who runs a tv shop solder them on for me for 20$

Needless to say a free broken LCD + 25$ and change = working 18" LCD Smile

Much appreciated.

User: inactive Posts:

hauschman · Joined: Aug 31, 2007 Posts: 1

Thank you for the detailed instructions! Went to Radio Shack and bought the parts. It took me less than an hour to fix and have it up and running after only paying $5 for parts. I have worked on a lot circut boards over the years and do have two tips for you that really helped me. First when taking out the capacitors you can pinch them with pliers and the cap of the capacitor will relase for the stems. Then you can heat the sodered side and have plenty to pull from the other side. Second, after the capacitor is removed I heat the left over solder and put a pin into the hole. Then pull the pin out and the hole is big enough to put the new capacitor in. This also will reqire less heat time so you will not cook any other parts. Great instrutions! Hope this helps others!

bugmenot · Joined: Mar 12, 2007 Posts: 26

I had a similar problem with a HP D5061A - 15" LCD. It would power on, show the image for a split second and turn black.
I first suspected a bad inverter, and with a powerful light you could see the screen was showing the image, but the backlight was off.

I got these monitors (two identical with same problem) from a random person with no knowledge of usage or warranty. (legit, i promise Smile

)
They came from a company upgrading their equipment and this was apparently labeled as defect.

So i opened up the screen, searching for visibly damaged components, but with no luck. Measured the power supply and regulator circuits, but everything seemed fine.
I then just out of the blue went into the on screen menu and found the brightness setting set to 99 % (maximum).
After turning this down to around 50% it doesn't shut off the backlight anymore, success!

I think some guy in this thread said something about a safety feature in the inverter to shut it self off if there was something wrong with the CCFL bulbs. And i think this is exactly what was the problem in this case. When turned on now the backlight does seem a bit weak (on about 70%, not sure how high it will go and still function). I figure the CCFL is close to giving in and might have caused the company personnel to turn the brightness to a max, and by doing that crippling the backlight. When the IT department would look at it, it would just be considered broken by age and passed on to my contact.

All in all, I'm happy it works now, without having to mess around with any intestines.
I also have a HP D5062 lcd with no backlight, but this trick did nothing on that.
The lcd has a pretty nasty scratch in it, so it's not a big priority, but maybe i'll post what was wrong with it later - if I'll bother doing anything with it.

verbage · Joined: Dec 28, 2007 Posts: 7

Hey, add me to the FPD1830 "flickers and goes black after a second" club. And wow, I'm glad to have found this thread!

Given the age of the monitor, I'm hesitant to spend $100 to replace the whole inverter board only to have another component fail in the near future (like the actual CCFL lamps, for example). So I'm going to go XTS5000's route of replacing the four capacitors on the board.

Yesterday I pulled the inverter board out of my FPD1830, and desoldered the four capacitors in question. For the record, they are Sanyo-brand caps with a green sleeve and gold lettering. They are of the mini/short variety--only 7mm tall vs. the more common 11+mm. They have a diameter of 6.3mm. They have four lines of repeating markings on them. Three of the four marking lines are exactly the same--"100uF", "25V", and "105°C". The fourth marking line is variable--there are two versions with two of the caps being one version, and the remaining two caps being the other version. This variable marking is either "S.E.25" or "N.E.13".

I'm not sure what these "S.E.25" and "N.E.13" codes mean--maybe they are just batch numbers??? Can anybody comment? Since the caps are in parallel anyways, this probably doesn't matter.

verbage · Joined: Dec 28, 2007 Posts: 7

Ah, just wanted to add some tips for desoldering as after reading through SteveW's detailed post at http://25yearsofprogramming.com/blog/20070403.htm, well, many of you might be totally discouraged.

Get yourself a higher powered soldering iron as the cooling/heating cycles on the lower powered ones make them frustrating to work with for higher temp silver-based solder. Radioshack has a decent 40-watt iron for $8 (see http://www.radioshack.com/product/index.jsp?productId=2062738).

I used a simple desoldering bulb to remove excess solder to begin with. Radioshack has one for $4.50 (see http://www.radioshack.com/product/index.jsp?productId=2062742).

Something like the Kronus Helping Hands item that wild1210 suggested a while back is extremely useful. I have one of these, and it made the job a cinch. Basically, grab on to one of the capacitors with one of the alligator clips. Then use your soldering iron to melt one of the solder contacts, and twist the board so that the capacitor lead pulls up through the molten solder. Wait a second, and do the same operation on the second lead from the same capacitor. Repeat 2-3 times a necessary until the cap (with both leads perfectly intact) simply works its way up, and pops free from the board. Literally, with a nice hot iron, you can free each capacitor in just 10-20 seconds like this.

After you remove each cap, a few more minutes of cleaning with the desoldering bulb, a needle, and an X-acto knife will leave you in great shape for the replacements. You can use rubbing alcohol on a Q-tip to clean off rosin, etc.

I think the most critical element here is the higher powered iron to easily and quickly melt the silver solder. While the Helping Hands are ultra-useful, you could always substitute it by asking a friend with steady hands to help you with some needle-nosed pliers. But unless you can easily/quickly melt the silver solder, you'll probably find yourself frustrated.

verbage · Joined: Dec 28, 2007 Posts: 7

I went to digikey.com and mouser.com to find replacements for my four caps, and quickly realized there was an overwhelming selection. So I've had to do some research.

I looked at the 35V and 50V Radioshack models that SteveW suggested, but those parts are only rated up to 85°C whereas the Sanyo-brand ones from my inverter board clearly have a higher temp rating (105°C). Sure the 85°C ones would work for a while, but I'd rather use the parts with higher temp specs now, and hopefully avoid having to do this surgery again in another year.

One other thing distinctive about the caps on my board was the color scheme--a green sleeve with gold letterings. I vaguely recalled this meant something, so I downloaded a Sanyo capacitor product lineup to figure it out. Of all the different series listed in that document, all the ones with a green sleeve and gold lettering were specified as low impedance models, so that helps limit the search for a replacement.

Anyway, I've narrowed down the choice to either Panasonic-brand FM series or Nichicon-brand HE series caps. I'll compare the specs sheets tomorrow, and then place an order.

verbage · Joined: Dec 28, 2007 Posts: 7

I placed an order for some of the Panasonic FM series caps at digikey.com this afternoon. Once I get them installed, I'll give you all a status report, and let you know if the story has a happy ending.

I ordered many more caps than I need (qty. 100) for the simple fact that I was going to be charged a $5 handing fee because my order was below the $25 minimum, and shipping was going to be $6. So I'd have to pay $11 "processing" just for $1 worth of caps. My rationale was that other folks would be interested in the same caps, but not want to get slammed with the $11 processing. So I'd be happy to send you out a small pack of the caps for just $2. But first, let's see if they work well.

dschonew · Joined: Jan 02, 2008 Posts: 1

While not dealing with this specific monitor, I just brought back to life a ViewSonic by changing only one capacitor. I have had a ViewSonic VA720 sitting around for a couple of years collecting dust. I finally decided that it was time to repair or recycle the unit. After finding one "pregnant" capacitor the monitor is back up and running.

In case someone else has the same model I would recommend checking the 3300 microfarad 16V capacitor. The cap in my monitor was bulging but had not burst. I replaced 20 capacitors on an old ABIT board a few years ago and still had some capacitors that got from Mouser laying around.

Rather than ordering one capacitor and paying for the shipping I merely wired two 1500 microfarad 16V capacitors in parallel to obtain approximately the correct capacity.

The monitor is working great as I write this.

Hopefully everyone else has success with their repairs.

Werebo

Cooo, it's nice to read about repairs involving a soldering-iron, rather than just swapping boards over

verbage · Joined: Dec 28, 2007 Posts: 7

Just an observation here that may be useful to others. Using a digital multimeter, I checked the capacitance values of the four Sanyo-brand caps I pulled. The two "S.E.25" ones both rang up at ~101 uF while the two "N.E.13" ones rang up at ~92 and ~95 uF. I was sort of surprised to see this--I guess I was expecting at least one to show a really "bad" value thus justifying the backlight's brief startup-->flicker-->failure sequence. But then I was doing some reading that suggests many bad capacitors give good capacitance value readings with a multimeter when they are tested loose and out of circuit. To test whether a capacitor actually works, it has to be in a circuit under real-life load conditions.

verbage · Joined: Dec 28, 2007 Posts: 7

I was happy to find the digikey.com shipment on my doorstep when I returned home this evening. But I was thrilled when the FPD1830 popped up a stable gorgeous image free from flicker-and-die syndrome after making the fix! So one less FPD1830 in a landfill thanks to XTS5000's troubleshooting and fix!!!

verbage · Joined: Dec 28, 2007 Posts: 7

No problems with my fixed FPD1830--still working great after a couple of days of "burn-in", so the Panasonic FM series caps seem to work great. As I mentioned above, I ordered many more than necessary (qty. 100) just because I was going to get hammered with shipping/handling anyways. So, if anyone is interested in a few of the caps for their own repair, I'd be happy to send you 6 (4 for repair, 2 in case of problems) by mail for $2. If you are interested, send me a PM. And, thanks once again to XTS5000 for the troubleshooting and solution!

CJWOLF · Joined: Feb 13, 2008 Posts: 1

Hey, add me to the FPD1830 "flickers and goes black after a second" club. And wow, I'm glad to have found this thread!

JUST PERFORMED capacitor extraction and replacement awesome. thanks everyone!!!!!!

Werebo

Well done Verbage and thanks for posting the cure, glad you got it sorted

Allo CJWolf and welcome to Lockergnome Forum

NameCaster · Joined: Mar 11, 2008 Posts: 2

I've read through this thread and there is some very insightful and thought filled info but for the life of me I can't understand why anybody would solder in four 100uf caps ran in parallel rather than one 470uf to replace them all.

The first time I fixed one of these FPD1830 I replaced the four 100uf caps with two 220uf caps because that is all I had at hand, but from then on I always just remove the stock 100uf's and drop a 470uf in their place. The only reason I use the 470uf is that it is cheaper than the 400uf and the extra microfarads don't hurt a thing.

Cheers!
-Dave

NameCaster · Joined: Mar 11, 2008 Posts: 2

abeauch · Joined: Mar 03, 2008 Posts: 1

I just finished replacing the caps I purchased from Verbage for my Gateway FPD1830 and wanted to report that the monitor now works great. I picked this up from someone who was giving it away. Nice monitor for two dollars worth of caps and a stamp. Thanks Verbage! Very Happy

yoefool · Joined: Mar 21, 2008 Posts: 1

I work for acompany that buys a ton of those HP 19" LCD monitors and i would say about 1 out of 11 burn out within a 1 year period.

You can open it up and replace the lamps in there. It will cost you about $15-$25 to purchase the lamps but like I said.. it's a real pain to do it.

Hope this helps you out.