A computer components & hardware forum. HardwareBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » HardwareBanter forum » System Manufacturers & Vendors » Gateway Computers
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

polarity of power cord - gateway fpd1520



 
 
Thread Tools Display Modes
  #41  
Old April 13th 08, 11:07 AM posted to alt.sys.pc-clone.gateway2000,sci.electronics.repair
Arfa Daily
external usenet poster
 
Posts: 49
Default polarity of power cord - gateway fpd1520


"zirath" wrote in message
news:RrcMj.2161$vz2.1500@trndny05...
Arfa Daily wrote:
The fact that the light stays green, is a good sign. What you next
need to do, is to shine a strong desklamp or hand flashlamp at the
screen at an angle, after it has gone back to black. If you can then
see an image on the screen, that indicates that the backlamp tubes
are not staying alight. This could well be because either the
inverter is faulty, or that a worn tube is making the inverter shut
down. Either is quite a common fault condition.

Arfa

I was able to see the image on the screen - but the monitor remained
black the whole time (it didn't go back to black).
(I shined a bright light on the monitor at an angle).
OK. Well that tells us that the whole monitor part is working, and the
failure is in the LCD screen backlighting circuit. It is generally a
bit fiddly, but it is repairable if you are that way inclined. Unless
you are able (or want to) just throw it back where you got it from.

Arfa
I'm into trying to repair it.

Is there info somewhere on how to do it?

Thanks for your help.


If the screen comes apart easily, start by examining the backlight tubes.
Be careful when extracting them as they are quite fragile. If any are
badly blackened at the ends, suspect them. It's hard to test the
inverter, without having known good tubes to connect to it. If you have a
'scope, you can get a good idea by looking to see if you have waveform at
the primaries of each of the tube high voltage drive transformers. If you
do get a momentary burst that then disappears, this could be because the
inverter is detecting a bad tube, and shutting down. You might see the
tubes initially flash up, and you might see one not do so. You can
disconnect the tubes one at a time, and see if that keeps the inverter
running, and if it does, you can cross connect the tubes to the opposite
inverter outputs, to prove the drive electronics. Inverters and tubes are
available from a number of sources. See, for instance,

http://www.lcdparts.net/ccfl.aspx

http://www.ergpower.com/pdf30/cross.pdf

http://www.ergpower.com/

Arfa


One thing I started wondering about after you were saying it could be a
problem with the adapter--

The picture of the original adapter that came with the monitor says the
plug is supposed to be 6.5mm o.d. 4.4mm i.d. and 9.5mm long. (Thanks to
Michael Terrell -
http://www.lcdpayless.com/productpag...productId=237).

The measurements of the plug that came with the adapter I got (from ebay)
are : 5.5x2.5 / 9.5mm.

Could this be the problem?


As long as the plug is 'making' ok to the centre pin, it shouldn't be a
problem. However, the way round that you have described it sounds wrong. If
the original was looking for a plug with an id of 4.4mm, (which is *very*
big for this type of plug) that would suggest that the monitor has a 'thick'
pin, which I'm surprised that your replacement at just 2.5mm, will fit over.
2.5mm is a pretty 'standard' size.

However, if you can see an image with an external light shone at the screen,
that says that the plug *is* making ok, and the whole monitor is working,
less the backlights. So no, I don't think that will be the problem.

Arfa


  #42  
Old April 14th 08, 11:23 AM posted to alt.sys.pc-clone.gateway2000,sci.electronics.repair
zirath
external usenet poster
 
Posts: 23
Default polarity of power cord - gateway fpd1520

Arfa Daily wrote:
The fact that the light stays green, is a good sign. What you next
need to do, is to shine a strong desklamp or hand flashlamp at the
screen at an angle, after it has gone back to black. If you can then
see an image on the screen, that indicates that the backlamp tubes are
not staying alight. This could well be because either the inverter is
faulty, or that a worn tube is making the inverter shut down. Either
is quite a common fault condition.

Arfa

I was able to see the image on the screen - but the monitor remained
black the whole time (it didn't go back to black).
(I shined a bright light on the monitor at an angle).
OK. Well that tells us that the whole monitor part is working, and the
failure is in the LCD screen backlighting circuit. It is generally a bit
fiddly, but it is repairable if you are that way inclined. Unless you are
able (or want to) just throw it back where you got it from.

Arfa

I'm into trying to repair it.

Is there info somewhere on how to do it?

Thanks for your help.


If the screen comes apart easily, start by examining the backlight tubes. Be
careful when extracting them as they are quite fragile. If any are badly
blackened at the ends, suspect them. It's hard to test the inverter, without
having known good tubes to connect to it. If you have a 'scope, you can get
a good idea by looking to see if you have waveform at the primaries of each
of the tube high voltage drive transformers. If you do get a momentary burst
that then disappears, this could be because the inverter is detecting a bad
tube, and shutting down. You might see the tubes initially flash up, and you
might see one not do so. You can disconnect the tubes one at a time, and see
if that keeps the inverter running, and if it does, you can cross connect
the tubes to the opposite inverter outputs, to prove the drive electronics.
Inverters and tubes are available from a number of sources. See, for
instance,

http://www.lcdparts.net/ccfl.aspx

http://www.ergpower.com/pdf30/cross.pdf

http://www.ergpower.com/

Arfa



I was able to disassemble the front and back panels.

Is the inverter the part that has the power button and various setting
buttons? I was able to disconnect this part.

I didn't see the lcd tubes. The lcdparts.net site didn't have this model
of gateway listed and the instructions for getting to the tubes for the
gateway models they had didn't match.
  #43  
Old April 14th 08, 04:52 PM posted to alt.sys.pc-clone.gateway2000,sci.electronics.repair
Arfa Daily
external usenet poster
 
Posts: 49
Default polarity of power cord - gateway fpd1520


"zirath" wrote in message
news:2hGMj.5445$eg2.332@trndny06...
Arfa Daily wrote:
The fact that the light stays green, is a good sign. What you next
need to do, is to shine a strong desklamp or hand flashlamp at the
screen at an angle, after it has gone back to black. If you can then
see an image on the screen, that indicates that the backlamp tubes
are not staying alight. This could well be because either the
inverter is faulty, or that a worn tube is making the inverter shut
down. Either is quite a common fault condition.

Arfa

I was able to see the image on the screen - but the monitor remained
black the whole time (it didn't go back to black).
(I shined a bright light on the monitor at an angle).
OK. Well that tells us that the whole monitor part is working, and the
failure is in the LCD screen backlighting circuit. It is generally a
bit fiddly, but it is repairable if you are that way inclined. Unless
you are able (or want to) just throw it back where you got it from.

Arfa
I'm into trying to repair it.

Is there info somewhere on how to do it?

Thanks for your help.


If the screen comes apart easily, start by examining the backlight tubes.
Be careful when extracting them as they are quite fragile. If any are
badly blackened at the ends, suspect them. It's hard to test the
inverter, without having known good tubes to connect to it. If you have a
'scope, you can get a good idea by looking to see if you have waveform at
the primaries of each of the tube high voltage drive transformers. If you
do get a momentary burst that then disappears, this could be because the
inverter is detecting a bad tube, and shutting down. You might see the
tubes initially flash up, and you might see one not do so. You can
disconnect the tubes one at a time, and see if that keeps the inverter
running, and if it does, you can cross connect the tubes to the opposite
inverter outputs, to prove the drive electronics. Inverters and tubes are
available from a number of sources. See, for instance,

http://www.lcdparts.net/ccfl.aspx

http://www.ergpower.com/pdf30/cross.pdf

http://www.ergpower.com/

Arfa


I was able to disassemble the front and back panels.

Is the inverter the part that has the power button and various setting
buttons? I was able to disconnect this part.

I didn't see the lcd tubes. The lcdparts.net site didn't have this model
of gateway listed and the instructions for getting to the tubes for the
gateway models they had didn't match.


The inverter board is usually long and thin, and has a multipin plug going
to somewhere around its middle, and thickish high voltage wires coming out
of each end to go to the backlight tube connections at either side of the
screen. I seem to recall that there are pictures of inverter boards on at
least one of those sites. they all look pretty much alike generally, if not
in detail. Each backlight tube will have two of these high voltage wires at
either end, that will go back to connectors located at the inverter board
ends.

Arfa


 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
di-604 power cord donut Homebuilt PC's 0 September 26th 07 07:03 AM
Compaq JBL Pro speakers - need to know polarity of power supply Larry Dawson Compaq Computers 0 July 13th 05 04:13 AM
Gateway 9150 Needs Power Cord & Battery netnews.comcast.net Gateway Computers 1 July 28th 04 12:08 PM
Power Cord? Eugene Dell Computers 6 June 12th 04 10:18 PM
Power Cord? Scott Gateway Computers 1 December 11th 03 09:40 PM


All times are GMT +1. The time now is 08:24 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 HardwareBanter.
The comments are property of their posters.