Phillips 190CW LCD Screen Clicking/Ticking

[pgrigs]

Hi All,
Would love a little help if possible.

Have the above screen, which dropped off the stand and hit the desk pretty hard, and stopped displaying a picture.

The green LED would light up on the front, and the screen would flash amber/orange if you attached/re-attached the dvi plug, but then revert to a black screen.

Opened it up and saw a bulged capacitor on the video board - bought the exact same replacement, soldered it on and then turned the pc on while it was still in parts (with no earth admitedly, but it was only a test and i made sure sure to not touch the board, even after power down).

Now the PSU is clicking when you apply power - but no obvious damage to caps... The LED won't turn on either. But you completely disconnect the video board from the actual screen, the clicking noise goes away and the LED lights up (which still has me thinking it's another cap and not any of the fuses).

But there is so many of them...

I came across this thread: https://www.badcaps.net/forum/showthread.php?t=10183

Can any help me figure out which caps are linked to my PWM controller?

PSU board number is 715G1899-1-PH1. Tried looking for a diagram map of the board online but no luck.

Thanks!

[PlainBill]

Re: Phillips 190CW LCD Screen Clicking/Ticking

Hi All,
Would love a little help if possible.

Have the above screen, which dropped off the stand and hit the desk pretty hard, and stopped displaying a picture.

The green LED would light up on the front, and the screen would flash amber/orange if you attached/re-attached the dvi plug, but then revert to a black screen.

Opened it up and saw a bulged capacitor on the video board - bought the exact same replacement, soldered it on and then turned the pc on while it was still in parts (with no earth admitedly, but it was only a test and i made sure sure to not touch the board, even after power down).

Now the PSU is clicking when you apply power - but no obvious damage to caps... The LED won't turn on either. But you completely disconnect the video board from the actual screen, the clicking noise goes away and the LED lights up (which still has me thinking it's another cap and not any of the fuses).

But there is so many of them...

I came across this thread: https://www.badcaps.net/forum/showthread.php?t=10183

Can any help me figure out which caps are linked to my PWM controller?

PSU board number is 715G1899-1-PH1. Tried looking for a diagram map of the board online but no luck.

Thanks!

The best way to get assistance is to take a picture of the top of the power supply and attach it to your next post using 'Manage Attachments' - below the text entry area. A second picture showing the bottom of the power supply would also be appropriate. Pictures with a resolution close to the maximum of 2000 x 2000 pixels are best. Also, note the links in my signature.

PlainBill

[pgrigs]

Re: Phillips 190CW LCD Screen Clicking/Ticking

Hi PlainBill,

Thanks for responding - really appreaciate it.

Uploaded pics as per your links - tried to get as close as possible to res type using microsoft viewer. If the pics aren't good enough, I'll upload from a different pc that has adobe lightroom on it.

Cheers!

[PlainBill]

Re: Phillips 190CW LCD Screen Clicking/Ticking

Hi PlainBill,

Thanks for responding - really appreaciate it.

Uploaded pics as per your links - tried to get as close as possible to res type using microsoft viewer. If the pics aren't good enough, I'll upload from a different pc that has adobe lightroom on it.

Cheers!

They aren't real good, but will do for now.

First, to answer your question, the large rectangular object wrapped in yellow tape near the center of the board is the SMPS transformer. There are two small electrolytic caps to the left of it, I believe they are C906 and C907. Those two caps are critical to the SMPS operation.

Next, I'm going to suggest a few tests. Refer to the picture of the bottom of the board. In the upper left corner is the connector for the cable going to the signal card. I can see points labeled GND, 5V, 12V, DIM and ON/OFF.

With the power supply plugged in, but disconnected from the signal card, measure the voltage from GND to 5V, 12V, DIM, and ON/OFF.

Now unplug the power supply, wait a few minutes, connect the cable to the signal card but disconnect the signal card from the LCD panel, plug in the power supply and measure the same points.

Repeat these steps with the LCD panel connected to the signal card.

What brand and series of cap did you use for the replacement on the signal board?

There is a very good chance the monitor is toast. The fact that it was dropped and the power supply appears to shut down when connected to the LCD panel would suggest a damaged panel. Before writing it off, at least check the orientation of the cap you replaced.

PlainBill

[sabre504]

Re: Phillips 190CW LCD Screen Clicking/Ticking

Last time i dealt with a dropped one the screen survived intact but the ccfls
had shattered inside at the end that had the impact .

Worth tilting the screen back and forth see if you hear any rattling .

(not highly technical i know )

[pgrigs]

Re: Phillips 190CW LCD Screen Clicking/Ticking

Will do those tests and get back to you - I'll probably change the little caps too just to see if it nips this problem in the bud.

The brand of cap I used was a Rubyson - identical specs to the one i replaced.

I just don't understand why it went from an orange screen to a clicking noise.

Shook the monitor - no noise of anything flailing about. Also, the orange screen it had prior to cap removal suggests thats not it either either.

Thanks for your help all - this is one hell of a site and community!

[pgrigs]

Re: Phillips 190CW LCD Screen Clicking/Ticking

Just to add to my previous post - i changed the two caps next to the transformer - CLICKING HAS DISAPPEARED!! You were right, so the PSU is operation again.

But...

Screen now has reverted to an amber orange colour for a couple of seconds, and then switches off.

Complete cap replacement on the videoboard next point of order?

[PlainBill]

Re: Phillips 190CW LCD Screen Clicking/Ticking

The brand of cap I used was a Rubyson - identical specs to the one i replaced.

Rubyson or Rubycon?

Just to add to my previous post - i changed the two caps next to the transformer - CLICKING HAS DISAPPEARED!! You were right, so the PSU is operation again.

But...

Screen now has reverted to an amber orange colour for a couple of seconds, and then switches off.

Complete cap replacement on the videoboard next point of order?

DAMIFIKNOW.

My suggestion is to hook it up to a working computer. If the screen goes black while displaying the desktop, and the power button stays green (or blue), you have a 'two seconds to black' problem, very possibly due to a broken CCFL as sabre504 suggested. If the power button turns off, or goes to amber, definitely recap the signal board.

PlainBill

[pgrigs]

Re: Phillips 190CW LCD Screen Clicking/Ticking

You're right - Rubycon.

To your other question - the "green" light stays constant - doesn't revert to any flashing.

But ... I did shake the monitor and nothing loose bangs around as suggested.

Had to pull the cobwebs off the metre - doesn't work either for some reason (even after battery change). Haven't used it for awhile and it was in the garage for the last 3 years, so I think it has some moisture damage (winters in Aus can get really damp!).

I thought bad caps (ones that are on the way out) could also lead to a 2 seconds to black problem. Memory may serve me wrong, but I thought Dells or Samsungs had the 2 second to balck problem because of detoriating caps.

[PlainBill]

Re: Phillips 190CW LCD Screen Clicking/Ticking

You're right - Rubycon.

To your other question - the "green" light stays constant - doesn't revert to any flashing.

But ... I did shake the monitor and nothing loose bangs around as suggested.

Had to pull the cobwebs off the metre - doesn't work either for some reason (even after battery change). Haven't used it for awhile and it was in the garage for the last 3 years, so I think it has some moisture damage (winters in Aus can get really damp!).

I thought bad caps (ones that are on the way out) could also lead to a 2 seconds to black problem. Memory may serve me wrong, but I thought Dells or Samsungs had the 2 second to balck problem because of detoriating caps.

Just about any monitor made with cheap caps can have 'two seconds to black'. There is some debate about the order, but the possible causes (in order) are bad caps, aged CCFL, bad wiring to the CCFLs, shorted transformer, broken CCFL, problem with the protection circuit.

PlainBill