Planar PL1700-BK - backlights go out

[KyleSTL]

Re: Planar PL1700-BK - backlights go out

Very nice, I'll give that a try. Thanks for your help. I'll post how it goes.

If it is the CCFL's, how much do they usually go for, and how difficult (or risky) are they to replace? Any good websites to buy CCFLs?

EDIT: Nevermind, saw the links posted earlier in the thread.

[jetadm123]

Re: Planar PL1700-BK - backlights go out

This is my first post on Badcaps forums. I work for an industrial company we recently had a plague of monitors dying. They were about to hand them off to an E-waste company for free, and I offered to take a couple home and see if they just needed some caps replaced (I replaced caps on several motherboards before with a perfect record).

The (9) Viewsonic VA902s have the same symptoms so I went ahead and ordered enough to fix 10 of them after I got the first one opened and counted up the blown caps. There were a couple other models (1) Planar PL1910 [that had 5 bad caps - also on order] and (1) Planar PL1700. After opening the PL1700 I noted that none of the caps looked damaged (looks just like De3rcr's picture in post #48 in this thread). I reassembled it, and plugged it into my computer and turned it on. The screen came on for about two seconds, but instead of being white the entire screen had a very pink hue. After it went dark, I could still see the text in very bright light (i.e. no backlight at all). What could this possibly have stemmed from? Bad CCFL? Inverter? Caps?

If it's an easy fix/diagnosis I might do it. If it's going to be time-consuming or difficult, I'd sooner just let that one go to the e-wasters (as I'm doing this on my own time). Just trying to save our company a little money, and getting a couple monitors out of the deal (per our IT manager).

Any help would be greatly appreciated.

Sounds like the CCFL's are failing (pink hue), which in turn are drawing too much current and tripping the protection circuit. To verify if it's the CCFL's: if you still have one of the other monitors lying around, place it next to the Planar and try connecting Planar power supply CCFL outputs to the CCFL's of the good monitor. If it works correctly, then you have verified it's the CCFL's.

[KyleSTL]

Re: Planar PL1700-BK - backlights go out

This is my first post on Badcaps forums. I work for an industrial company we recently had a plague of monitors dying. They were about to hand them off to an E-waste company for free, and I offered to take a couple home and see if they just needed some caps replaced (I replaced caps on several motherboards before with a perfect record).

The (9) Viewsonic VA902s have the same symptoms so I went ahead and ordered enough to fix 10 of them after I got the first one opened and counted up the blown caps. There were a couple other models (1) Planar PL1910 [that had 5 bad caps - also on order] and (1) Planar PL1700. After opening the PL1700 I noted that none of the caps looked damaged (looks just like De3rcr's picture in post #48 in this thread). I reassembled it, and plugged it into my computer and turned it on. The screen came on for about two seconds, but instead of being white the entire screen had a very pink hue. After it went dark, I could still see the text in very bright light (i.e. no backlight at all). What could this possibly have stemmed from? Bad CCFL? Inverter? Caps?

If it's an easy fix/diagnosis I might do it. If it's going to be time-consuming or difficult, I'd sooner just let that one go to the e-wasters (as I'm doing this on my own time). Just trying to save our company a little money, and getting a couple monitors out of the deal (per our IT manager).

Any help would be greatly appreciated.

[De3rcr]

Re: Planar PL1700-BK - backlights go out

Finally got the ccfl's and got a chance to relpace the bad one. Good thing I bought 2 cause the first one I installed worked for about an hour then started flickering so I took apart the panel again and found that the end of the ccfl I replaced had broken where the wire was soldered(must have happened when I put the silicon end cap on), replaced it again and it's working great now.

Thanks to retiredcaps, alexanna, PlainBill for the help.

[De3rcr]

Re: Planar PL1700-BK - backlights go out

If you decide to just replace the one ccfl, check the overstock stuff for possible deal/match at

http://ccflwarehouse.com/blandovsp.html

http://ccfldirect.com/blowoutlamps.html

Your 2 links didn't have the size I needed. I ordered 2 from ccflwarehouse yesterday, one to replace the burnt one and the other as a spare or to replace the other one that is next to it, or if I screw up replacing the first one.

Thanks for your and PlainBill's and alexanna help. Definitly a learning experince that will be useful. Will post back when I get the ccfl's.

[retiredcaps]

Re: Planar PL1700-BK - backlights go out

I am unsure on what to tell you on how many to order it looks like they have a 4 lamp kit fof $30.00 plus about $5.00 shipping, that sounds like a good price to me.
Al

If you decide to just replace the one ccfl, check the overstock stuff for possible deal/match at

http://ccflwarehouse.com/blandovsp.html

http://ccfldirect.com/blowoutlamps.html

[retiredcaps]

Re: Planar PL1700-BK - backlights go out

Please inspect everything closely, just because a ccfl dose not show dark edges dose not mean that it is not causing problems,
Look at the return wires where they attach to the bulb very closely for any indication of discoloration, A gentle tug is helpful to find poor soldering,

Post #109 in this thread shows what alexanna is talking about

https://www.badcaps.net/forum/showth...?t=8589&page=6

Funny, 3 bad ccfls cases in the last 24 hours.

[alexanna]

Re: Planar PL1700-BK - backlights go out

Please inspect everything closely, just because a ccfl dose not show dark edges dose not mean that it is not causing problems,
Look at the return wires where they attach to the bulb very closely for any indication of discoloration, A gentle tug is helpful to find poor soldering,
I really like ccflwarehouse.com
They welcome phone orders and there tech support is very knowledge,
They can look up your panel number and get you exactly what you need.
I would order some silicone end caps, along with a small amount of kapton tape
I am unsure on what to tell you on how many to order it looks like they have a 4 lamp kit fof $30.00 plus about $5.00 shipping, that sounds like a good price to me.
Al

[De3rcr]

Re: Planar PL1700-BK - backlights go out

BTW, which J90 connector was that ccfl with the black ends connected to?

It was J905. The other bulb looks a little discolored, Should I replace both?

[PlainBill]

Re: Planar PL1700-BK - backlights go out

So swap it around and hook the Planar lcd panel to the LG?
I don't think I'm going to see any image because I 'm not going to have the ribbon cable from the Planar hooked to the LG panel

The only thing I haven't done of Plainbill's is to ground pin 2 on U901, to me it looks like it doesn't go anywhere.

Based on the latest results, that isn't necessary.

PlainBill

[retiredcaps]

Re: Planar PL1700-BK - backlights go out

So I took apart the Planer lcd panel and one of the ccfl's on the bottom had black ends.

BTW, which J90 connector was that ccfl with the black ends connected to?

[retiredcaps]

Re: Planar PL1700-BK - backlights go out

So I took apart the Planer lcd panel and one of the ccfl's on the bottom had black ends.

Where's a good place to order new bulbs and should I replace both?

See this thread as it talks about a supplier ...

https://www.badcaps.net/forum/showth...lwarehouse.com

[De3rcr]

Re: Planar PL1700-BK - backlights go out

I plugged the LG panel into the Planar inverter board and the ccfl's stayed on for 2 hours. So I took apart the Planer lcd panel and one of the ccfl's on the bottom had black ends.

Where's a good place to order new bulbs and should I replace both?

This will be my first time replacing ccfl's any advice? I'm getting better with my soldering so I think I can get the wires onto the bulbs.

[alexanna]

Re: Planar PL1700-BK - backlights go out

Could this be a possibility?
This is what is I think maybe going on, If I understand things correctly this is like a series circuit, But this an AC voltage source so I am not sure if this correct way to explain it.
J905 bulb has a return wire that's just hanging on by a couple of strands of wire.
I am thinking the design of the inverter transformer circuitry allows more voltage available to overcome the added resistance when the ccfl is in one position, but when it's installed in the other connector there is less voltage available to properly light the ccfl causing shut down.
Please correct me if I am wrong.
Al.

[De3rcr]

Re: Planar PL1700-BK - backlights go out

If you already tested the procedure outlined in post #51, please retest it again (after the resoldering - something might have changed).

OK,
This is getting crazy, I followed post #51 rather then explain it I put it in a spreadsheet(attached).

The thing is that after I did the last 2 I put it back to normal it stayed on for 15 minutes(even heated it with a blow dryer while it was on) then I uplugged it and let it sit for 5 minutes then plugged it back in and it stayed on for about 5 minutes then the ccfl's shut off.

[De3rcr]

Re: Planar PL1700-BK - backlights go out

OK, I get it now.

[retiredcaps]

Re: Planar PL1700-BK - backlights go out

If you already tested the procedure outlined in post #51, please retest it again (after the resoldering - something might have changed).

[retiredcaps]

Re: Planar PL1700-BK - backlights go out

So swap it around and hook the Planar lcd panel to the LG?
I don't think I'm going to see any image because I 'm not going to have the ribbon cable from the Planar hooked to the LG panel

Since the Planar is the one having the problem, we want to keep as much as the original Planar parts in the test loop as possible. Hope the following makes sense. If not, please ask.

LG = good/spare ccfl.

1) Connect a working computer to VGA port of Planar. Make sure the computer is on and it displays the wallpaper or your desktop. Turn off any screen saver/sleep mode on your computer.

2) TURN POWER OFF and unplug the Planar monitor and wait 1 minute

3) disconnect Planar J903 and plug in LG into J903, leave J904 into Planar ccfl #2, J905 into Planar ccfl #3, and J906 into Planar ccfl#4

4) plug in monitor and turn monitor on - note if "2 seconds to black" occurs - if all ccfls stay lit for more than 2 minutes, move on to the next test

5) TURN POWER OFF and unplug the Planar monitor and wait 1 minute

6) disconnect Planar J904 and plug in LG into J904, leave J903 into Planar ccfl #1, J905 into Planar ccfl #3, and J906 into Planar ccfl#4

7) plug in monitor and turn monitor on - note if "2 seconds to black" occurs - if all ccfls stay lit for more than 2 minutes, move on to the next test

8) TURN POWER OFF and unplug the Planar monitor and wait 1 minute

9) disconnect Planar J905 and plug in LG into J905, leave J903 into Planar ccfl #1, J904 into Planar ccfl #2, and J906 into Planar ccfl#4

10) plug in monitor and turn monitor on - note if "2 seconds to black" occurs -if all ccfls stay lit for more than 2 minutes, move on to the next test

11) TURN POWER OFF and unplug the Planar monitor and wait 1 minute

12) disconnect Planar J906 and plug in LG into J906, leave J903 into Planar ccfl #1, J904 into Planar ccfl #2, and J905 into Planar ccfl#3

13) plug in monitor and turn monitor on - note if "2 seconds to black" occurs - see if all ccfls stay lit for more than 2 minutes

[De3rcr]

Re: Planar PL1700-BK - backlights go out

After you get done testing all of PlainBill's suggestions, can you retest with just one ccfl at a time following the instructions in section 5

https://www.badcaps.net/forum/showpo...1&postcount=14

For your situation, the LG would be the good/spare ccfl. Again, you don't have to remove the ccfl from the LG, just stretch the Planar ccfl cable to the LG. Please hookup a computer to the Planar so you can see a display.

So swap it around and hook the Planar lcd panel to the LG?
I don't think I'm going to see any image because I 'm not going to have the ribbon cable from the Planar hooked to the LG panel

The only thing I haven't done of Plainbill's is to ground pin 2 on U901, to me it looks like it doesn't go anywhere.

[retiredcaps]

Re: Planar PL1700-BK - backlights go out

I only plugged the all 4 LG ccfl's into the Planar ps/inverter board, I had to keep the Planar logic board attached so it would turn on, did not have a computer hooked to the LG panel, I only saw the ccfl's come on for about 5 seconds then they shut off.

After you get done testing all of PlainBill's suggestions, can you retest with just one ccfl at a time following the instructions in section 5

https://www.badcaps.net/forum/showpo...1&postcount=14

For your situation, the LG would be the good/spare ccfl. Again, you don't have to remove the ccfl from the LG, just stretch the Planar ccfl cable to the LG. Please hookup a computer to the Planar so you can see a display.