Planar PL1700-BK - backlights go out

[De3rcr]

I have this monitor and when I hooked it up to a pc it was working then after XP loaded the backlight went out I could still see the image with a flashlight. I'm going to replace the caps first but I have a mixture of different caps.

Here are the caps on the power board now

4 x 470uf 25v lelon rxk
2 x 1000uf 10v elite ej
1 x 10uf 16v elite pf
1 x 10uf 100v elite pf

what I have to replace them are

470uf 25v nichicon pw
1000uf 10v panasonic fm or nichicon he

I have to buy the 10uf ones but digikey has fc's and pw's to replace those. My question is, is it ok to mix all these different caps?

[PlainBill]

Re: Planar PL1700-BK - backlights go out

I have this monitor and when I hooked it up to a pc it was working then after XP loaded the backlight went out I could still see the image with a flashlight. I'm going to replace the caps first but I have a mixture of different caps.

Here are the caps on the power board now

4 x 470uf 25v lelon rxk
2 x 1000uf 10v elite ej
1 x 10uf 16v elite pf
1 x 10uf 100v elite pf

what I have to replace them are

470uf 25v nichicon pw
1000uf 10v panasonic fm or nichicon he

I have to buy the 10uf ones but digikey has fc's and pw's to replace those. My question is, is it ok to mix all these different caps?

Yes. You notice the manufacturer did that. OK, that's probably going to give you any confidence. But the answer remains the same. In terms of life expectancy there is no difference between Nichicon and Panasonic as long as the caps are good enough for the application.

PlainBill

[De3rcr]

Re: Planar PL1700-BK - backlights go out

OK, I'm going to order the 10uf from digikey and post back with what happens.

[retiredcaps]

Re: Planar PL1700-BK - backlights go out

I have this monitor and when I hooked it up to a pc it was working then after XP loaded the backlight went out I could still see the image with a flashlight.

Quick test. If you lower the brightness and constrast to 20/20 respectively, does the monitor stay on longer?

The reason I ask is that most "2 seconds to black" is 2 seconds or less to black. With yours, I know XP takes at least 1 minute to boot and am curious if lowering the settings help the monitor stay on longer?

Great photos. I'm jealous that I can see grass in the background. Here I just finished shoveling snow and it is piled about 2 feet on one side. Anyone still playing Beach Volleyball on Daytona Beach?

[De3rcr]

Re: Planar PL1700-BK - backlights go out

Quick test. If you lower the brightness and constrast to 20/20 respectively, does the monitor stay on longer?

The reason I ask is that most "2 seconds to black" is 2 seconds or less to black. With yours, I know XP takes at least 1 minute to boot and am curious if lowering the settings help the monitor stay on longer?

Great photos. I'm jealous that I can see grass in the background. Here I just finished shoveling snow and it is piled about 2 feet on one side. Anyone still playing Beach Volleyball on Daytona Beach?

I was able to lower the brightness and contrast and was able to get the room where I'm working darker, the backlights do seem to stay longer and they flicker(kinda like a pulse) the whole time until they shut off. they stay on about 2 min. And if I unplug it and let it sit awhile it does the same thing.

I ordered the 10uf caps and am going to replace all the caps.

I haven't seen anyone playing volleyball lately, but some people are still working on their tan.

[De3rcr]

Re: Planar PL1700-BK - backlights go out

OK, I replaced all the caps and now the backlights turn off in about 30 seconds.

I replaced the caps with

470uf 25v nichicon pw
1000uf 10v nichicon he
10uf 16v nichicon pw
10uf 100v panasonic fc

[retiredcaps]

Re: Planar PL1700-BK - backlights go out

OK, I replaced all the caps and now the backlights turn off in about 30 seconds.

If you have a fan, trying cooling the power/inverter board and see if it stays on longer.

[alexanna]

Re: Planar PL1700-BK - backlights go out

I was able to lower the brightness and contrast and was able to get the room where I'm working darker, the backlights do seem to stay longer and they flicker(kinda like a pulse) the whole time until they shut off. they stay on about 2 min. And if I unplug it and let it sit awhile it does the same thing.

I ordered the 10uf caps and am going to replace all the caps.

I haven't seen anyone playing volleyball lately, but some people are still working on their tan.

I do not see where you tried substituted one or two good ccfls to see if the back lights will stay on.
The flickering you mention makes me wonder if a ccfl may be causing your problem.
Al.

[De3rcr]

Re: Planar PL1700-BK - backlights go out

I do not see where you tried substituted one or two good ccfls to see if the back lights will stay on.
The flickering you mention makes me wonder if a ccfl may be causing your problem.
Al.

Unfortunately I don't have any spare parts to check the ccfl's. I was hoping to maybe track it to the inverter. I'm trying to follow retiredcaps "2 secs to black" post, but I'm not sure I'm taking the right readings with the dmm.

[retiredcaps]

Re: Planar PL1700-BK - backlights go out

Unfortunately I don't have any spare parts to check the ccfl's.

What about the cooling fan? Backlights on for 30 seconds seems more like thermal related to me.

[De3rcr]

Re: Planar PL1700-BK - backlights go out

What about the cooling fan? Backlights on for 30 seconds seems more like thermal related to me.

Tried cooling the board, that doesn't keep the lights on any longer. But if I unplug it then plug it back in the lights stay on for about 5 or 6 seconds.

[retiredcaps]

Re: Planar PL1700-BK - backlights go out

Unfortunately I don't have any spare parts to check the ccfl's. I was hoping to maybe track it to the inverter. I'm trying to follow retiredcaps "2 secs to black" post, but I'm not sure I'm taking the right readings with the dmm.

Okay, list the readings that you are getting when measuring the inverter transformer T901. We will interpret them.

[De3rcr]

Re: Planar PL1700-BK - backlights go out

Okay, list the readings that you are getting when measuring the inverter transformer T901. We will interpret them.

OK, I used the white dot on the transformer as pin 1

1-2=open
1-3=open
1-4=open
1-5=.581
1-6=open
1-7=open
1-8=open

2-3=0
2-4=open
2-5=open
2-6=0
2-7=0
2-8=open

3-4=open
3-5=open
3-6=0
3-7=0
3-8=open

4-5=open
4-6=open
4-7=open
4-8=.581

5-6=open
5-7=open
5-8=open

6-7=0
6-8=open

7-8=open

hope this is what you needed

[retiredcaps]

Re: Planar PL1700-BK - backlights go out

OK, I used the white dot on the transformer as pin 1

1-2=open 2-3=0 3-4=open 4-5=open 5-6=open 6-7=0
1-3=open 2-4=open 3-5=open 4-6=open 5-7=open 6-8=open
1-4=open 2-5=open 3-6=0 4-7=open 5-8=open
1-5=.581 2-6=0 3-7=0 4-8=.581
1-6=open 2-7=0 3-8=open
1-7=open 2-8=open
1-8=open

7-8=open

hope this is what you needed

What scale did you use on your multimeter?

The 1-5 and 4-8 reading of .581 suggest the secondaries are okay.

I have another test for you to try since you do not have another or spare ccfl. I'll post the instructions in a new post below.

[De3rcr]

Re: Planar PL1700-BK - backlights go out

dmm set on 2k

[retiredcaps]

Re: Planar PL1700-BK - backlights go out

dmm set on 2k

Okay, that explains the 0. Your multimeter is probably showing 0.x ohm, but the resolution says it is 0. If you remeasure the 0 ohm reading with a 200 ohm scale, it will probably show 0.x ohm.

[retiredcaps]

Re: Planar PL1700-BK - backlights go out

This section will probably make it into rev 0.3 of the guide, but right now for those without a spare or good ccfl, here it is.

=== snip ===

Pay ATTENTION as there is a VERY HIGH VOLTAGE (600V to 1000V)! As a safety precaution, it might help to have someone around when you are doing this if something screws up.

Alternatively, if you do not have a spare CCFL, try this test for a completely dead non working CCFL.

a) TURN POWER OFF and unplug the monitor and wait 1 minute
b) disconnect all CCFLs expect #1
c) plug in monitor and turn monitor on - note if "2 seconds to black" occurs
d) TURN POWER OFF and unplug the monitor and wait 1 minute
e) disconnect all CCFLs expect #2
f) plug in monitor and turn monitor on - note if "2 seconds to black" occurs
g) TURN POWER OFF and unplug the monitor and wait 1 minute
h) disconnect all CCFLs expect #3
i) plug in monitor and turn monitor on - note if "2 seconds to black" occurs
j) TURN POWER OFF and unplug the monitor and wait 1 minute
k) disconnect all CCFLs expect #4
l) plug in monitor and turn monitor on - note if "2 seconds to black" occurs

If one of the CCFLs does not show "2 seconds to black", it is likely physically damaged (cracked) or the wiring is completely broken to it. Take out that CCFL and inspect it. If all 4 CCFLs do show "2 seconds to black", one or more can still be bad. This test only tests for a completely dead CCFL or completely broken wiring.

Replacing a CCFL is a delicate operation. See "Lamp Soldering Tutorial" at http://ccflwarehouse.com/lasotu.html to see what steps are involved.

[retiredcaps]

Re: Planar PL1700-BK - backlights go out

The inverter controller chip is OZ960. Here is the datasheet.

We may need to take measurements later? Note the pins are very close to each other and caution is needed when measuring voltage as it easy to short something out.

[retiredcaps]

Re: Planar PL1700-BK - backlights go out

BTW, the test results in post #17 is highly dependent on the inverter controller IC.

I haven't looked through OZ960, but having just one ccfl connected may not be a valid test.

Thanks to alexanna for pointing this out to me.

[De3rcr]

Re: Planar PL1700-BK - backlights go out

This section will probably make it into rev 0.3 of the guide, but right now for those without a spare or good ccfl, here it is.

=== snip ===

Pay ATTENTION as there is a VERY HIGH VOLTAGE (600V to 1000V)! As a safety precaution, it might help to have someone around when you are doing this if something screws up.

Alternatively, if you do not have a spare CCFL, try this test for a completely dead non working CCFL.

a) TURN POWER OFF and unplug the monitor and wait 1 minute
b) disconnect all CCFLs expect #1
c) plug in monitor and turn monitor on - note if "2 seconds to black" occurs
d) TURN POWER OFF and unplug the monitor and wait 1 minute
e) disconnect all CCFLs expect #2
f) plug in monitor and turn monitor on - note if "2 seconds to black" occurs
g) TURN POWER OFF and unplug the monitor and wait 1 minute
h) disconnect all CCFLs expect #3
i) plug in monitor and turn monitor on - note if "2 seconds to black" occurs
j) TURN POWER OFF and unplug the monitor and wait 1 minute
k) disconnect all CCFLs expect #4
l) plug in monitor and turn monitor on - note if "2 seconds to black" occurs

If one of the CCFLs does not show "2 seconds to black", it is likely physically damaged (cracked) or the wiring is completely broken to it. Take out that CCFL and inspect it. If all 4 CCFLs do show "2 seconds to black", one or more can still be bad. This test only tests for a completely dead CCFL or completely broken wiring.

Replacing a CCFL is a delicate operation. See "Lamp Soldering Tutorial" at http://ccflwarehouse.com/lasotu.html to see what steps are involved.

OK,
checked the backlights and if you look at my first pic the connectors on the far left and far right don't show any light, but the middle 2 give "2 secs to black" so I guessing I need to order some cclf's. But I can check that chip if needed.