Need help DCLCD 19" LCD Monitor - I already replaced caps

[DJM_PHX]

Re: Need help DCLCD 19" LCD Monitor - I already replaced caps

I have a P/S-Inverter board # LM004 Rev 3.
If That will help you with any part identification, I will do my best to help you
Al.

On the bottom of the board, is ZD102 a 15V Zener diode?
see post #153

[alexanna]

Re: Need help DCLCD 19" LCD Monitor - I already replaced caps

On the bottom of the board, is ZD102 a 15V Zener diode?
see post #153

I do not know if this will help you but, The markings that I can see are a big yellow band on one end and what looks to be black or green band in the centre. My eyes are way past the 40 year old mark!
Zd102, ZD104 and ZD105 all appear to be the same color to my eyes.
Al.

[SMITHWHO]

Re: Need help DCLCD 19" LCD Monitor - I already replaced caps

http://www.ludens.cl/Electron/esr/esr.html
try this web sight for build your own cap testor
sincerly j.r. smith

[Th3_uN1Qu3]

Re: Need help DCLCD 19" LCD Monitor - I already replaced caps

As it is it isn't too accurate, but it'll be enough to make a good/bad type of test.

[DJM_PHX]

Re: Need help DCLCD 19" LCD Monitor - I already replaced caps

Ok, I have replaced the bad schottky diode (10A-100V) and the burned ZD102 on the bottom of the board.

What is the yellow unit? (see attached pic)

Does any one know if ZD102 is in fact a Zener diode?
Do we know its specs (I used a 15V 500mA)?

[DJM_PHX]

Re: Need help DCLCD 19" LCD Monitor - I already replaced caps

I have removed the diode at ZD102 and I am measuring ~0 ohms across all of the devices connected to the yellow unit including the schottky diodes and the 5 caps in the filter part. Everything seems to be connected to ground!

[DJM_PHX]

Re: Need help DCLCD 19" LCD Monitor - I already replaced caps

I removed the yellow unit and still have everything connected to ground. I think I will just take all of the caps off and the schottky diodes and sink off and measure them all.

[Dr Laser]

Re: Need help DCLCD 19" LCD Monitor - I already replaced caps

I would like to say thanks to this forum to give me an idea why my dclcd was blinking. I replaced the main (big) cap and also other one which was inflated. Now monitor works fine.

[Don P]

Re: Need help DCLCD 19" LCD Monitor - I already replaced caps

I looked through all the threads to try & find my problem, but no luck. So, here goes... My DCLCD 19" "died" a couple of days ago. I noticed that after coming back to it after a while, it would not "wake up". I tried pressing the power button, but that didn't work. What did work (a few times) was to unplug it and then plug it back in. Eventually, the entire screen would be white. That's all I get on it now. The other observation was that as I was plugging it back in, the front panel power led would be momentarily purple before going to red, at which point I had the white screen, and again, the power switch is ineffective.

Thank You in advance for reading this and any comments concerning my display!

[PlainBill]

Re: Need help DCLCD 19" LCD Monitor - I already replaced caps

I looked through all the threads to try & find my problem, but no luck. So, here goes... My DCLCD 19" "died" a couple of days ago. I noticed that after coming back to it after a while, it would not "wake up". I tried pressing the power button, but that didn't work. What did work (a few times) was to unplug it and then plug it back in. Eventually, the entire screen would be white. That's all I get on it now. The other observation was that as I was plugging it back in, the front panel power led would be momentarily purple before going to red, at which point I had the white screen, and again, the power switch is ineffective.

Thank You in advance for reading this and any comments concerning my display!

(Sigh). Open up the monitor, take pictures of the power supply (top and bottom) and the signal card. Attach them to your next post using 'Manage Attachments' - below the text entry area.

PlainBill

[Don P]

Re: Need help DCLCD 19" LCD Monitor - I already replaced caps

Sorry about that.... here are 2 pictures. One of the signal board, the other is the bottom of the power supply board. I don't know why it won't let me load the third one, I'll post the top of the power supply in the next post...

[Don P]

Re: Need help DCLCD 19" LCD Monitor - I already replaced caps

Here is the top of the power supply board...

[alexanna]

Re: Need help DCLCD 19" LCD Monitor - I already replaced caps

You power supply looks like it's of a newer design.
You have some budging capacitors just above the large transformer with the yellow tape on it.
Replace all the capacitors with the exception of the really big on.
I have to warn you there is the possibility of damage to the logic or signal board from low voltage, but it's worth a shot to replace the capacitors.

[PlainBill]

Re: Need help DCLCD 19" LCD Monitor - I already replaced caps

Sorry about that.... here are 2 pictures. One of the signal board, the other is the bottom of the power supply board. I don't know why it won't let me load the third one, I'll post the top of the power supply in the next post...

Sometimes the site is just obnoxious. I'll give you a C+ on the pictures - grading on the curve, of course. A couple of things are apparent.

1. You have at least two bad caps. One has obviously vented.

2. The monitor was built with Capxon caps.

Capxon caps aren't the worst possible caps, but they aren't far from it. I suggest replacing all 10 of the electrolytic caps (with the exception of the large one) with Panasonic FM or FR series caps. There is a good chance that is all it will take to repair the monitor. You may be able to dig the values from this thread. Double check that against the actual capacitors in your monitor.

PlainBill

[Don P]

Re: Need help DCLCD 19" LCD Monitor - I already replaced caps

Thank You both for your input on this... guess it's time to break out the soldering iron and see what I need... and where to find them... I think I saw a link somewhere here that recommended a good place to find them. I can solder, but to be truthful, I'm really appreciating your knowledge, especially in the area of good/marginal caps...

[PlainBill]

Re: Need help DCLCD 19" LCD Monitor - I already replaced caps

Thank You both for your input on this... guess it's time to break out the soldering iron and see what I need... and where to find them... I think I saw a link somewhere here that recommended a good place to find them. I can solder, but to be truthful, I'm really appreciating your knowledge, especially in the area of good/marginal caps...

I agree with everything alexanna said.

I FINALLY took a look at your profile, and learned you are in the USA. My preferred supplier is DigiKey. Here is a link to a procedure for locating suitable caps.

I suggest selecting suitable replacements, then posting the list here BEFORE you place the order. Someone here will verify your selections seem to be correct.

PlainBill

[Don P]

Re: Need help DCLCD 19" LCD Monitor - I already replaced caps

As requested, I removed the caps and have them listed for verification. Ok, here's what I have for info. I'm posting a new picture, with number labels above each cap. first number is picture label, second is ps board part# third is capacitance fourth is voltage....

1 C33 220uF 25V
2 C72 220uF 25V
3 C14 220uF 25V
4 C13 470uF 35V
5 C11 470uF 35V
6 C33 220uF 25V
7 C12 1000uF 16V
8 C12 1000uF 16V
9 C33 220uF 25V
10 C7 10uF 50V

First column is quantity, 2nd is capacitance/voltage third is digilink part # fourth is panasonic #

5 220uF/25V P12383-ND EEU-FM1E221
2 470uF/35V P14440-ND EEU-FR1V471L
2 1000uF/16V P14398-ND EEU-FR1C102
1 10uF/50V P11250-ND EEU-FC1H100

Once again, Thank You for your time, consideration, and great technical advice!

Don

[alexanna]

Re: Need help DCLCD 19" LCD Monitor - I already replaced caps

Could you also measure the capacitor sizes, along with the volt and UF values?

The diameter and height of the capacitors are a critical measurements,They need to fit where you want them to go.
Example #7 and #8 look to be 12.5MMx20MM.Or 10mmx20mm?
#9 looks like 10mmx20MM.

[Don P]

Re: Need help DCLCD 19" LCD Monitor - I already replaced caps

Yikes !!!!!!!!!!!!!! Thank You !!!!!!!!!! I had the wrong stuff.. my 10 & 220 uF were ok, but you hit the caps right on the head!!!!!!! my 1000 & 470 were both the wrong size....10x20 on both sets...

Now my updated order list looks like this....

5 220uF/25V P12383-ND EEU-FM1E221
2 470uF/35V P12415-ND EEU-FM1V471
2 1000uF/16V P12366-ND EEU-FM1C102
1 10uF/50V P11250-ND EEU-FC1H100


Nice catch... I once again bow to the geniuses...

[PlainBill]

Re: Need help DCLCD 19" LCD Monitor - I already replaced caps

One point that should be made - it's not necessary the replacements match the original dimensions. The only criteria is they must fit in the available space.

If originals were 15 mm in diameter and 20 mm high, 12.5mm x 25mm would be acceptable IF you had enough height.

PlainBill