Planar PL1700-BK - backlights go out

[De3rcr]

Re: Planar PL1700-BK - backlights go out

Sorry,
J906 far right
J903 far left

Yes, and J903 comes on but not as bright as J904

[retiredcaps]

Re: Planar PL1700-BK - backlights go out

And just to confirm, all the ccfls light up (when switched around) except when plugged into the "far right" connector?

[retiredcaps]

Re: Planar PL1700-BK - backlights go out

OK,
Taking the middle lights and pluging them into the outer sockets, the left one came on really dim and then shut off and the right one didn't come on at all.

Okay, just going forward and to make it easier to trace and follow, the far right is which J connector? J903, J904, J905 or J906?

[De3rcr]

Re: Planar PL1700-BK - backlights go out

Okay, I guess the next step is to see if it is the ccfl's or the circuitry that is driving them.

So plug the "working" middle ccfl into the far left. Then try the "working" middle ccfl into the far right.

Report the results.

OK,
Taking the middle lights and pluging them into the outer sockets, the left(J903) one came on really dim and then shut off and the right(J906) one didn't come on at all. I plugged the outer lights into the inner sockets and they came on bright and then shut off. So when the either light is plugged into the inner sockets(good ones I hope) they all come on bright and then shut off.

I didn't know you could switch the lights around like that(add that to my troubleshooting notebook).

[retiredcaps]

Re: Planar PL1700-BK - backlights go out

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.

Okay, I guess the next step is to see if it is the ccfl's or the circuitry that is driving them.

So plug the "working" middle ccfl into the far left. Then try the "working" middle ccfl into the far right.

Report the results.

[De3rcr]

Re: Planar PL1700-BK - backlights go out

Before ordering anything, give us a few hours to digest the results and study the OZ960 datasheet.

Additionally, you may not need new ccfls. It could be the ccfl wiring that is at fault.

I looked at that datasheet, I can't even fit that in my mouth let onlone digest it. I was just looking for ccfl's, but it's a topploy panel they look hard to find.

[retiredcaps]

Re: Planar PL1700-BK - backlights go out

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.

Before ordering anything, give us a few hours to digest the results and study the OZ960 datasheet.

Additionally, you may not need new ccfls. It could be the ccfl wiring that is at fault.

[uligli]

Re: Planar PL1700-BK - backlights go out

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?

That remembers me back in the 90's when i rent a volleyball Nes game to play

[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.

[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.

[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

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

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.

[De3rcr]

Re: Planar PL1700-BK - backlights go out

dmm set on 2k

[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

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

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

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.

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

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.