Question about Philips Televison & Video

3 Answers

I have a Philips 42PFL5432D/37 LCD TV that has no picture. The screen flashes once after power on then stays black. The green power light is not flashing but turns steady red sometimes after about 20 minutes. I do not see any bad/swollen capacitors anywhere. I checked inverter capacitors 951,952,953,955(suggested) with a multimeter and they all discharged. I also checked the white fuse next tothe power cord. What could be the problem?

Posted by on

  • 5 more comments 
  • dohcac Nov 18, 2009

    I checked the only fuse I see and it's good (120V). I actually dont know how to check the output voltage of the inverter but i did check every canister style capacitor and they all discharge. If i unplug the inverter from the main board the TV doesn't power on at all. If I unplug the slave the screen still flashes once. If i unplug the master the tv turns on but the screen does not flash. I have always heard the transformer "hummimg". And there is no backlight, not a black light. Totally dark room and cant see anything on screen.

  • dohcac Nov 20, 2009

    Ok, Me again. I serached online for a master backlight inverter as you suggested and found a few for sale. Before I commited to purchasing an inverter I continued to work on the TV. I unplugged not the power jack but what I would call the data jacks from the backlight master inverter and noticed upon power on that the TV flash was considerable longer. I alternated unplugging each and discovered the backlight would stay on if the menu/volume control board was disconnected???? I have not yet connected the TV to see if it gets a picture but yes the backlight is now on! Does this mean it could not be the backlight main inverter that's bad and actually something else?

  • dohcac Nov 21, 2009

    I researched and found the board in question is called a logic control board. When I unplug the flat data cable the backlight turns on but I can not get a picture. Backlight goes immediately when data cable is plugged back in. Data cable to logic control board connects to main backlight inverter. Keep in mind the power jack from the main board to the logic control board is dissconnected. The only connection to the logic control board when the data cable is connected is only the data cable and the backlight still goes out. Can this conclude what is bad with the TV?

  • dohcac Nov 27, 2009

    Ok. Well I purchased a used Master backlight inverter from discounttvparts.com and unfortunately the TV is still doing the same exact thing. Any suggestions on which board to change next? This is becoming coastly! Thanks

  • dohcac Dec 03, 2009

    Now I purchased a used tcon board and the TV is still doing the same thing? What now? Let me guess, by another board. I would have had better luck rolling dice. Thanks.

  • dohcac Dec 07, 2009

    Thanks for all the help. I purchased this TV (broken) $150 thinking I could fix it. Changed the main backlight inverter $60, the tcon board $25, and now the slave backlight inverter $60 and am still having the same problem. I have 24 volts DC going to each backlight inverter and 120 volts AC across the power inverter fuse at all times. I now found a power inverter online for $59 and a main control board for $79, which are the only other boards left to change in this TV, but think I am too deep into this TV to continue further especially after I read that the problem could be other things and not necessarily a board. Do you have any other suggestions? I have a multimeter....is there anything I can test for.

  • dohcac May 10, 2010

    Symptoms: At first TV would suddenly lose picture but kept sound. Would come back on after time. Then after some weeks no picture at all. Changed Master and Slave inverters and then T-con board.

    FIX: Finally, changed Main Control Board and TV works perfect.

×

Ad

3 Answers

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    President:

    An expert whose answer got voted for 500 times.

  • Philips Master
  • 749 Answers

You appear to have done a good deal of hunting already.

See if there is power to the inverter board after you turn on the TV. Should be about 24V. Note I do not have the schematics for this particular Philips, but I've seen others and they are more or less the same.

So first and foremost see if you have power to inverter or inverters, if they are two.

Actually even before that please make sure that "black" is "lack of backlight" as opposed to "backlight is there, but screen is black". It's easy to see that in a darker room as well as from the back side of the LCD assmebly when it's on.

We're dusscussing the case here where there's no backlight.

Measure the power to the inverter(s) with and without them being attached to the power board, i.e. make sure the power is there when they're not connected and then see if it is still there when they're connected.

Ideally, see how it changes from the moment you turn on the TV; some main boards turn off the backlight if the encounter power with the inverter, others do not.

There are few small fuses on the inverter board too, they are SMD. More often than not one of those is blown and sometimes it's without an apparent reason, i.e,. if you replace (or even short) it , the ivnerter will just work.

Most of the times they are blown for a good reason, though, and you need new inverter(s).

Finally, there is a minimal chance that a lamp or a lamp connection has gone bad. This is very tough to detect and usually is the last thing you would resort on checking,

Posted on Nov 18, 2009

  • 4 more comments 
  • CoppellTVRepair.com Nov 18, 2009

    based on what you clarified and my experience I'd bet the problem is in one of the inverters, most likely the main inverter.

    Look at the board part number - it's usually imprinted on the board itself - and look on eBay or Google for it.

    Another way to go about it is to type in the model number (usually without /37) followed by the word "inverter", e.g. "42pfl5432d inverter".

    My search yielded result board number VIT70023.80 and from there you start searching for this on eBay...find a reputable seller (like me, except I don't think I have it) and buy it.

    It might be the slave inverter, it might be the master, but from what you describe it's more likely the master.

    It's possible to nail it down, but it will require multimeter and some extra time.

    Hope that helps!

  • CoppellTVRepair.com Nov 20, 2009

    Well..what you say doesn't make much sense, at least to me.


    There's no volume control board that I know of. Considering, of course, I do not know that particular TV, but I don't recall another TV that has a particular volume control board.



    There *is* another type of approach where audio amplifier is on a separate board and it is possible that if the audio amplifier has shorted (burned) it could also block the backlight, yes. It would be unusual, but too unusual for the two of them to be related.



    If that is the case then you should be able to connect everything else and just power off the audio amplifier; by doing so you'll end up with no audio, but with fully functional television.

    You should try and do that if you can.



    For me, I could easily figure out what to try by looking at the opened TV - the boards and connections tell a lot.



    Finally , a word of advice - some power supplies tend to BLOW if you let them working without a load. The one you have in your Philips is hardly among them, but truth is you never know which is which until you see it happening.



    I had my first blow on me last week. I had read that some of them do it, but I've never seen one...until then. You just disconnect components in an attempt to isolate a problem and then out of a sudden - no short, no nothing - BOOOM - it was quite a flash!



    So...bear that in mind when experimenting :-)

  • CoppellTVRepair.com Nov 21, 2009

    You know, I should have asked you to look for that connection and try without it...some tvs have it and some do not and I got carried in your terminology and forgot to do the systematic approach.



    The board you're likely talking about is not called logic control board. It is called a tcon board (from "time control") and it's located in the upper center of the LCD, right?

    One cable leads from it to the main TV board (the computer) and another cable - flat cable - leads to the main inverter.



    What you;re saying is that when you disconnect the tcon from the main inverter then the backlight comes up.



    My guess is then that you need a tcon (often also called LCD controller) board rather than an inverter board.



    There is still a slight chance that it might be the inverter; there should be a way to make that sure by monitoring the signals sent by the tcon to the master inverter, but to be honest I do not know what are those and what exactly to be looking for. I have never had to troubleshoot that connection and while I'd love to do it, this is hardly the best opportunity to do so :-)



    THere is, in fact, a slight chance the problem may even be in the main board, since the main board sends the image to the tcon board and the tcon board stores it for dispatching to the LCD; if, for whatever reason, the main board does not send proper signal to the tcon, the tcon may figure it better shut the lights.


    I am just speculating here...don't remember seeing a case like that.



    Again, under the circumnstances I'd venture trying for a tcon board OR learning what exactly the tcon communicates with the inverter and listening there. In order to do that , though, you'll also need to learn in which cases the tcon shuts down the backlights and why.

    I'd be curious to learn it myself.

  • CoppellTVRepair.com Nov 28, 2009

    Have you read my comment from november 21st?

  • CoppellTVRepair.com Nov 28, 2009

    And another thing - if you can't or don't want to resell the inverter on yourself, try returning it back to the vendor. Most vendors will take parts back regardless of what their policy says. SOme may charge you 10% , some will just issue full refund (I myself am from the first kind).

  • CoppellTVRepair.com Dec 06, 2009

    Welcome to TV repair business, dude...sometimes it's nice and easy and sometimes you can kill a month over something that'll turn the last think you would have thought of. Especially in plasma screens.
    What we give you here is not a complete algorithm, but the approach taken by gaining experience with most common deffects by symptom.

    To give you an algorithm we'd need to have not only the full schematics, but also the service manual for the according TV! And even service manuals are rather far from complete problem detection algorithm, although they are the closest one can get to it.

    Anyway, you are right - here comes another board.

    The problem is any of the remaining boards can now be the problem: it can be the power board which, upon load, fails to supply 24V to the inverter. It could be the master logic board which turns the display off for no particular reason. Last but certainly not least it could be a bad lamp or bad lamp connection, which causes the circuit to break down. I've seen that last one many many times in a particular LCD backlight model.

    Not sure what I'd do if I were you.

    You can't easily test lamps and main boards are expensive.

    Maybe you should consider selling it on Craigslist to a local repairman and buying a new one?

    I mean yes, you can sure fix it sooner or later, the question is what would the whole process cost in terms of time and money...

×

Ad
  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

  • Philips Master
  • 5,807 Answers

You mentioned checked capacitors 951, 952, 953, 955 and are discharged ,

is these like the board you are having


I have a Philips 42PFL5432D/37 - 39bf304.jpg

Posted on Nov 20, 2009

  • 1 more comment 
  • Rommel Cana
    Rommel Cana Nov 20, 2009

    maybe you're right about it, it might be the digital board which is giving the signal to the inverter





  • Rommel Cana
    Rommel Cana Nov 21, 2009

    your logic control board may be bad then

    if you can measure voltages it would conclude more and confirm you are right.

    voltages of 24V particularly which goes to the inverter board. and the other voltages such as

    3.3V, the 5 V, the 12V


  • Rommel Cana
    Rommel Cana Dec 08, 2009

    take your time to measure voltages to be very sure, read the voltages i have stated above.

    and not guessing which board to replace.

    servicing the unit also requires a


    service manual


    , only with a fee

    just to guide you in troubleshooting the unit.


    But check first if the chassis part number is the same before ordering.

    Regards, and Enjoy the forthcoming holiday!


×

Ad
  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Master
  • 643 Answers

Hello and welcome to Fixya. That sounds very typical of a bad Inverter Board. The single flash after power on of the screen points out the culprit. There are cheap places to get the inverter board, here is a link for the master. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=270459657870&fromMakeTrack=true&ssPageName=VIP:watchlink:top:en ( the link above is for a cheaper used master, with a 30 day gurantee) And here is a link to a site that carries both the master and the slave. http://www.discount-merchant.com/ProductDetails.asp?ProductCode=1049150&Click=54985 To see the other new parts for the Tv model you have, click at the bottom right of the page where it says" Additional Stock"

Posted on Nov 18, 2009

  • Tre Elkins Nov 18, 2009

    If you have any further questions, please feel free to comment back!

×

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (for users in the US for now) and get all the help you need.
Goodluck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

How can i fix my Philips model 42PFL5432D/37 Flat screen TV that powers on, but no picture.


The main board to your TV is faulty. It is best to contact the authorized service center for Philips; because, it will be very difficult to get the main board to Philips brand TVs, and after the replacement, a firmware update too will be necessary. This is a skilled work. http://electronicshelponline.blogspot.com/

Jul 27, 2015 | Philips Televison & Video

1 Answer

Model #42PFL5432D/37 Not receiving power? when


i was a tv engineer for many years quite a while back now and when a led is flasing or pulsing it usualy means the tv's power supply is in over current mode wherebye it shuts down to prevent any further damage due to a part of the circuitry drawing excess current, high voltage transformer etc, you need to get a techie in, sorry.

Nov 03, 2010 | Philips Televison & Video

3 Answers

I have a 37" Philips (37PF9431D/37) flat panel tv. It won't power on. When you plug it in you can hear a click the green light stays on for a few seconds then goes out. I've checked the power board for bad...


i am having the same problem. My Phillips 37" 37PF9431D/37I LCD High Definition TV won;t turn on. When I press the power button i hear a click and the green light comes on for a couple of seconds and then the red light appears. I can;t figure it out. Did you find a solution?

May 20, 2010 | Philips 37PF7320A 37 in. HD-Ready LCD...

1 Answer

My Philips 37PFL5332D 37 has a black screen when


ur problem is the inverter board , or bad capacitor on power supply

Apr 14, 2010 | Philips 37PFL5332D 37 in. LCD Television

2 Answers

Philips 42PFL5432D-37 black screen


Hi,

There is a problem in this card ( TV turner ) some chip is over heating or as leakage ,there is s a big IC ( Microprocesor ) this chip if the cooling system is not good due to workload the screen will bahave that way
pls swap it get it changed .


good luck

Nov 30, 2009 | Philips 42PFL5332D 42 in. LCD Television

2 Answers

Philips lcd tv 42pfl5432d/37 no picture


based on what you clarified and my experience I'd bet the problem is in one of the inverters, most likely the main inverter.

Look at the board part number - it's usually imprinted on the board itself - and look on eBay or Google for it.

Another way to go about it is to type in the model number (usually without /37) followed by the word "inverter", e.g. "42pfl5432d inverter".

My search yielded result board number VIT70023.80 and from there you start searching for this on eBay...find a reputable seller (like me, except I don't think I have it) and buy it.

It might be the slave inverter, it might be the master, but from what you describe it's more likely the master.

It's possible to nail it down, but it will require multimeter and some extra time.

Hope that helps!

Nov 15, 2009 | Philips Televison & Video

1 Answer

Philips 30PF9946 D/37


You have sound but no picture. Green power light is on and NOT flashing. You get a screen flash or flicker on power-up or even a minute of screen before going all black. It is your inverter board. Common problem on LCDs (maybe more so on Phillips?). They are easy to replace (unplug-plug) and are available on the net.

Veritas

Feb 24, 2008 | Philips 30PF9946 30 in. HD-Ready Plasma...

Not finding what you are looking for?
Televison & Video Logo

Related Topics:

224 people viewed this question

Ask a Question

Usually answered in minutes!

Top Philips Televison & Video Experts

The Knight
The Knight

Level 3 Expert

74383 Answers

matt martin
matt martin

Level 3 Expert

1212 Answers

Donald DCruz
Donald DCruz

Level 3 Expert

17130 Answers

Are you a Philips Televison and Video Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...