Comments on: Any ideas on how to properly test voltage on the LCD inverter input and output? http://www.asklaptopfreak.com/laptop-notebook-help/2006/07/12/test-fl-inverter-input-and-output/ Your laptop computer doesn't work? Need help or support for your notebook? Ask the Laptop Freak! Mon, 30 Jan 2012 16:03:21 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: Kesh http://www.asklaptopfreak.com/laptop-notebook-help/2006/07/12/test-fl-inverter-input-and-output/comment-page-2/#comment-441811 Kesh Sun, 07 Aug 2011 19:43:16 +0000 http://www.asklaptopfreak.com/laptop-notebook-help/2006/07/12/test-fl-inverter-input-and-output/#comment-441811 Hello .... i have acer aspire 5610z ... and guess what... blacklight dont work. i tried with few invertors, but nothing. im sure that lamp work. that meens there is a motherboard problem, so... how many volts i need on inpunt to make it work ... can anyone write exactly wich wire(color) i need suply to get it work! thanks! Hello …. i have acer aspire 5610z … and guess what… blacklight dont work. i tried with few invertors, but nothing. im sure that lamp work. that meens there is a motherboard problem, so… how many volts i need on inpunt to make it work … can anyone write exactly wich wire(color) i need suply to get it work! thanks!

]]> By: tc http://www.asklaptopfreak.com/laptop-notebook-help/2006/07/12/test-fl-inverter-input-and-output/comment-page-2/#comment-330912 tc Mon, 21 Mar 2011 07:45:21 +0000 http://www.asklaptopfreak.com/laptop-notebook-help/2006/07/12/test-fl-inverter-input-and-output/#comment-330912 A quick test if you own a good Fluke or better DVM with frequency readout is to hold the probes about 1/4" - 1/2" a part and drag the two probes slowly across the bottom of the LCD where the inverter usually is. If the meter has a >50khz bandwidth and a sensitive AC mV setting (around ~50mv?) you should be able to pickup the inverter when the laptop is on and verify it's working you should see an AC signal locked at around 50-60 kHz. (Dell 8600 ran at 54.5khz) This should tell you the inverter is probably O.K. and you can move on to check the CCFL. (This all assumes you can see the LCD pixels on the screen with a flashlight and they are not all garbled.) *Always try reseating all the connectors on the main display cable and inverter cable first, that's usually the problem... "When you hear a stampede think horses, not zebras" and "Don't fix it if it ain't broke". :-) A quick test if you own a good Fluke or better DVM with frequency readout is to hold the probes about 1/4″ – 1/2″ a part and drag the two probes slowly across the bottom of the LCD where the inverter usually is. If the meter has a >50khz bandwidth and a sensitive AC mV setting (around ~50mv?) you should be able to pickup the inverter when the laptop is on and verify it’s working you should see an AC signal locked at around 50-60 kHz. (Dell 8600 ran at 54.5khz) This should tell you the inverter is probably O.K. and you can move on to check the CCFL. (This all assumes you can see the LCD pixels on the screen with a flashlight and they are not all garbled.)
*Always try reseating all the connectors on the main display cable and inverter cable first, that’s usually the problem…

“When you hear a stampede think horses, not zebras” and “Don’t fix it if it ain’t broke”. :-)

]]> By: dichar http://www.asklaptopfreak.com/laptop-notebook-help/2006/07/12/test-fl-inverter-input-and-output/comment-page-2/#comment-290968 dichar Mon, 17 Jan 2011 10:32:54 +0000 http://www.asklaptopfreak.com/laptop-notebook-help/2006/07/12/test-fl-inverter-input-and-output/#comment-290968 Hi Gays; I ve found a solution to the problem I gave bellow: I get the motherboard from its cover and I found precisely bellow the inverter cable connection on the motherboard a shortcut. Also on more then one place on the motherboard was traces of the liquid problem. Hi Gays;

I ve found a solution to the problem I gave bellow:
I get the motherboard from its cover and I found precisely bellow the inverter cable connection on the motherboard a shortcut. Also on more then one place on the motherboard was traces of the liquid problem.

]]> By: Dichar http://www.asklaptopfreak.com/laptop-notebook-help/2006/07/12/test-fl-inverter-input-and-output/comment-page-2/#comment-280927 Dichar Tue, 04 Jan 2011 10:07:19 +0000 http://www.asklaptopfreak.com/laptop-notebook-help/2006/07/12/test-fl-inverter-input-and-output/#comment-280927 Hello friends; When measuring the voltage on the input pins of the inverter of my laptop acer aspire 5735z, I found only 5 v, 0v, 0v, 4v. Further there is screen on the laptop, when plugging it on an extern display there is beeld. Can you guyes help me on this issue? What can be the problem? Thanks Dichar Hello friends;

When measuring the voltage on the input pins of the inverter of my laptop acer aspire 5735z, I found only 5 v, 0v, 0v, 4v.

Further there is screen on the laptop, when plugging it on an extern display there is beeld.

Can you guyes help me on this issue? What can be the problem?
Thanks

Dichar

]]> By: jamie http://www.asklaptopfreak.com/laptop-notebook-help/2006/07/12/test-fl-inverter-input-and-output/comment-page-2/#comment-277050 jamie Thu, 30 Dec 2010 01:18:49 +0000 http://www.asklaptopfreak.com/laptop-notebook-help/2006/07/12/test-fl-inverter-input-and-output/#comment-277050 hints and tips to test a laptop lcd inverter (i repair laptop 12 years experience) get an old laptop lcd what smashed take the backlight and plug it in to the suspected inverter if the light works then you know it your lcd monitor if it doesent light up the you got to back track it with a multimeter most laptop back lights are universal to the inverter meaning the connection just of hand when you get an old back light from just make sure it works or know it was working before the lcd got broken ps sorry about my spelling hints and tips to test a laptop lcd inverter (i repair laptop 12 years experience)
get an old laptop lcd what smashed take the backlight and plug it in to the suspected inverter if the light works then you know it your lcd monitor if it doesent light up the you got to back track it with a multimeter
most laptop back lights are universal to the inverter meaning the connection
just of hand when you get an old back light from just make sure it works or know it was working before the lcd got broken
ps sorry about my spelling

]]> By: bill http://www.asklaptopfreak.com/laptop-notebook-help/2006/07/12/test-fl-inverter-input-and-output/comment-page-2/#comment-186298 bill Thu, 17 Jun 2010 03:32:46 +0000 http://www.asklaptopfreak.com/laptop-notebook-help/2006/07/12/test-fl-inverter-input-and-output/#comment-186298 i have a ze4610us i replaced the lcd inverter 4 times and not working, cn1 is pin1-0 pin2-5.11 pin3-3.31 pin4-3.73 pin5-0 ant one know were on the we i can find out what the pin input volts are? i have a ze4610us i replaced the lcd inverter 4 times and not working, cn1 is pin1-0 pin2-5.11 pin3-3.31 pin4-3.73 pin5-0 ant one know were on the we i can find out what the pin input volts are?

]]> By: John Mac http://www.asklaptopfreak.com/laptop-notebook-help/2006/07/12/test-fl-inverter-input-and-output/comment-page-2/#comment-179958 John Mac Tue, 18 May 2010 23:25:48 +0000 http://www.asklaptopfreak.com/laptop-notebook-help/2006/07/12/test-fl-inverter-input-and-output/#comment-179958 OK, I solved my own problem... sort of. The bottom line was that the logic board was NOT outputting any voltage for the "dim control" input to the Inverter board. According to some other info found on the Internet, the "dim control" pin should have a voltage ranging from 0 to +4 volts depending on the dimming desired (where 0V = no light, 4V = max light). Since the logic board wasn't outputting any voltage on that pin, the backlight remained off. So, since I had no intention of buying a new logic board for such an old computer, I decided to just manually put +4V on the pin. Here's how I did it... First off, the CORRECT pin names and voltages to the input connector of the Inverter board are here (again, this is for Powerbook G4 17" Aluminum). This is slightly different than what I wrote in my original message... CHASSIS GROUND - Green wire (connector pin 1): Hardwired to chassis ground +12V SUPPLY - Black wire (connector pin 2): +12V CABLE GROUND - Gray wire (connector pin 3): 0V +5V SUPPLY - Blue wire (connector pin 4): +5V DIM CONTROL/ENABLE - Silver wire (connector pin 5): 0 to +4V depending on dimming So, it was the DIM CONTROL that was dead from the logic board. I had both 12v and 5v available to me at the input connector to the Inverter board so, at first I figured I'd just connect the 5v to DIM CONTROL. At first it worked but, after about 1 minute, the backlight would shut off, presumably because the Inverter was being "overdriven" and it has some kind of overcurrent shutdown circuitry. So, I went to plan B and, though experimentation, found that a 3K ohm resistor placed between pin 4 and pin 5 brought the voltage on the DIM CONTROL to +3.8V which kept the backlight bright without it shutting down. See pictures below. Now, for the bad news. Not only will the screen not dim (which I can live with), but it also won't shutoff when going into sleep mode (the display goes away, but the backlight remains lit). For the record, it DOES shutoff when the computer is ShutDown. But, this poses yet another challenge. Since I generally only use my computer from home while it is plugged in, I may not worry about this one for now. But, for many people, this might be a showstopper. None the less, I did get the backlight working. John http://www.djjohnnymac.com/images/IMG_4329.jpg http://www.djjohnnymac.com/images/IMG_4330.jpg http://www.djjohnnymac.com/images/IMG_4331.jpg OK, I solved my own problem… sort of. The bottom line was that the logic board was NOT outputting any voltage for the “dim control” input to the Inverter board. According to some other info found on the Internet, the “dim control” pin should have a voltage ranging from 0 to +4 volts depending on the dimming desired (where 0V = no light, 4V = max light). Since the logic board wasn’t outputting any voltage on that pin, the backlight remained off. So, since I had no intention of buying a new logic board for such an old computer, I decided to just manually put +4V on the pin. Here’s how I did it…

First off, the CORRECT pin names and voltages to the input connector of the Inverter board are here (again, this is for Powerbook G4 17″ Aluminum). This is slightly different than what I wrote in my original message…
CHASSIS GROUND – Green wire (connector pin 1): Hardwired to chassis ground
+12V SUPPLY – Black wire (connector pin 2): +12V
CABLE GROUND – Gray wire (connector pin 3): 0V
+5V SUPPLY – Blue wire (connector pin 4): +5V
DIM CONTROL/ENABLE – Silver wire (connector pin 5): 0 to +4V depending on dimming

So, it was the DIM CONTROL that was dead from the logic board. I had both 12v and 5v available to me at the input connector to the Inverter board so, at first I figured I’d just connect the 5v to DIM CONTROL. At first it worked but, after about 1 minute, the backlight would shut off, presumably because the Inverter was being “overdriven” and it has some kind of overcurrent shutdown circuitry. So, I went to plan B and, though experimentation, found that a 3K ohm resistor placed between pin 4 and pin 5 brought the voltage on the DIM CONTROL to +3.8V which kept the backlight bright without it shutting down. See pictures below.

Now, for the bad news. Not only will the screen not dim (which I can live with), but it also won’t shutoff when going into sleep mode (the display goes away, but the backlight remains lit). For the record, it DOES shutoff when the computer is ShutDown. But, this poses yet another challenge. Since I generally only use my computer from home while it is plugged in, I may not worry about this one for now. But, for many people, this might be a showstopper. None the less, I did get the backlight working.

John

http://www.djjohnnymac.com/images/IMG_4329.jpg
http://www.djjohnnymac.com/images/IMG_4330.jpg
http://www.djjohnnymac.com/images/IMG_4331.jpg

]]> By: John Mac http://www.asklaptopfreak.com/laptop-notebook-help/2006/07/12/test-fl-inverter-input-and-output/comment-page-2/#comment-179226 John Mac Thu, 13 May 2010 16:35:17 +0000 http://www.asklaptopfreak.com/laptop-notebook-help/2006/07/12/test-fl-inverter-input-and-output/#comment-179226 Dead LCD Backlight on Mac Powerbook G4 Aluminum 17"... OK, so I'm pretty handy with my Powerbook. In the past, I've replaced 2 different hard drives, a DVD-R drive and a few other things. In short, I've torn my Mac apart and put it back together successfully on numerous occasions. By this latest problem has really stumped me. I've read up on everything I can find on the Internet and changed out many parts, but still my LCD backlight is dead. Here is what I've done so far... 1) First, I assumed it was the Inverter board, so I ordered a replacement, opened up the screen (man, that was a bear) and installed it. Still, no backlight. 2) Next, assumed it was the inverter cable. Repeated above process with new cable. No light. But old cable was damaged (one wire broken), so it seemed like that was a clue. But still no light with new cable. 3) Next, assumed it might be the backlight itself, so I ordered one (complete with compatible 2-pin connector so no soldering needed). I didn't actually install it (which is an even bigger bear than lid removal), but I did plug it into the inverter output to test it out and... you guessed it... no love. 4) I figured that somewhere along the way, I burned out the replacement inverter board that I bought (OK, I put a meter across the outputs). So I bought ANOTHER replacement inverter. Plugged it in, powered it up... still no backlight (I tried it first with the new replacement bulb just in case original bulb was shorted out). I have since tested the outputs of the Inverter using the "new Morris Rosenthal technique" outlined in this article above (Harbor Freight meter on kHz setting and probes an inch or so away acting as antennas). When I do that, I get no frequency reading at all on the meter (0 kHz). But, as he said, maybe this is a high frequency inverter and the meter can't sense frequencies that high. At this point, I am completely stumped. I checked the input voltages to the inverter board and the seem OK, although I can't find anything on the Internet that states exactly what they should be. But they aren't zero (at least not all of them). Here's what they are... Silver wire (pin 1, perhaps): 0V Blue wire (2): +5V Gray wire (3): 0V Black wire (4): +12V Green wire (5): hardwired to ground So, I'm in for about 90 bucks so far in parts and the thing is still dead. Oh yeah and, by the way, I know it's the backlight because I can see faint images on the screen AND the laptop works fine when connected to an external monitor. I already have a newer MacBook Pro that I use for everyday stuff, but it would really be nice to get the old G4 working again. Anyone have any suggestions about where to go from here? John Dead LCD Backlight on Mac Powerbook G4 Aluminum 17″…

OK, so I’m pretty handy with my Powerbook. In the past, I’ve replaced 2 different hard drives, a DVD-R drive and a few other things. In short, I’ve torn my Mac apart and put it back together successfully on numerous occasions. By this latest problem has really stumped me. I’ve read up on everything I can find on the Internet and changed out many parts, but still my LCD backlight is dead. Here is what I’ve done so far…

1) First, I assumed it was the Inverter board, so I ordered a replacement, opened up the screen (man, that was a bear) and installed it. Still, no backlight.
2) Next, assumed it was the inverter cable. Repeated above process with new cable. No light. But old cable was damaged (one wire broken), so it seemed like that was a clue. But still no light with new cable.
3) Next, assumed it might be the backlight itself, so I ordered one (complete with compatible 2-pin connector so no soldering needed). I didn’t actually install it (which is an even bigger bear than lid removal), but I did plug it into the inverter output to test it out and… you guessed it… no love.
4) I figured that somewhere along the way, I burned out the replacement inverter board that I bought (OK, I put a meter across the outputs). So I bought ANOTHER replacement inverter. Plugged it in, powered it up… still no backlight (I tried it first with the new replacement bulb just in case original bulb was shorted out).

I have since tested the outputs of the Inverter using the “new Morris Rosenthal technique” outlined in this article above (Harbor Freight meter on kHz setting and probes an inch or so away acting as antennas). When I do that, I get no frequency reading at all on the meter (0 kHz). But, as he said, maybe this is a high frequency inverter and the meter can’t sense frequencies that high.

At this point, I am completely stumped. I checked the input voltages to the inverter board and the seem OK, although I can’t find anything on the Internet that states exactly what they should be. But they aren’t zero (at least not all of them). Here’s what they are…

Silver wire (pin 1, perhaps): 0V
Blue wire (2): +5V
Gray wire (3): 0V
Black wire (4): +12V
Green wire (5): hardwired to ground

So, I’m in for about 90 bucks so far in parts and the thing is still dead. Oh yeah and, by the way, I know it’s the backlight because I can see faint images on the screen AND the laptop works fine when connected to an external monitor. I already have a newer MacBook Pro that I use for everyday stuff, but it would really be nice to get the old G4 working again. Anyone have any suggestions about where to go from here?

John

]]> By: mehboob http://www.asklaptopfreak.com/laptop-notebook-help/2006/07/12/test-fl-inverter-input-and-output/comment-page-2/#comment-175845 mehboob Tue, 20 Apr 2010 08:27:34 +0000 http://www.asklaptopfreak.com/laptop-notebook-help/2006/07/12/test-fl-inverter-input-and-output/#comment-175845 I think all of them written the input voltages of inverter. i need to know about the output of the inverter which is going to the inverter on two wires ( Red and White). what are voltages available on those pins. Thank You I think all of them written the input voltages of inverter. i need to know about the output of the inverter which is going to the inverter on two wires ( Red and White).

what are voltages available on those pins.
Thank You

]]> By: edi http://www.asklaptopfreak.com/laptop-notebook-help/2006/07/12/test-fl-inverter-input-and-output/comment-page-2/#comment-172467 edi Mon, 29 Mar 2010 10:10:25 +0000 http://www.asklaptopfreak.com/laptop-notebook-help/2006/07/12/test-fl-inverter-input-and-output/#comment-172467 my acer aspire 4720 In my case I connected the “+” lead of the multimeter to the pin 1 on the connector and the “-” lead to the ground trace around the screw hole don't output 19 volt but the cable is ok.what testing in dhe board? my acer aspire 4720
In my case I connected the “+” lead of the multimeter to the pin 1 on the connector and the “-” lead to the ground trace around the screw hole don’t output 19 volt but the cable is ok.what testing in dhe board?

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