Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

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Default TFT monitor repair tips

Hello,

Can anyone point me towards some websites which can be of
help when dealing with lcd monitor repair.
Schematics, panel reference lists, repair tips, troubleshooting...
Any help would be welcome as google wasn't so helpful.

Cheetah
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Default TFT monitor repair tips


I don't want to dissapoint you, but component level service for the
LCD and Plasma display's are not normaly supported by any of the
manufactures. They are mainly serviced at the module level only, as
like servicing a PC computer. After warranty, they are usualy
considered not feasible to service, unless the fault is something
simple.

Full service manuals for many of these types of displays are usualy
difficult or impossible to obtain. After the warranty periods for most
of this type of technology is finished, spare modules and parts may
not be available unless you can find a scapper unit with good parts.
The exception is if you can find some generic parts that will work.

When factering in the cost of the circuit boards and the laour, the
dropping of the replacement cost, after warranty service is usualy
considered not worth the cost. When troubleshooting and servicing this
type of technology the tools, and instruntation required is fairly
expensive.

If you want to service these types of monitors, try to see if you can
negotiate warrenty contract with some of the manufactures. Be
prepaired to invest a fair amount of dollars to get going with this.


Jerry G.








On Aug 17, 1:55 pm, CheetahHugger wrote:
Hello,

Can anyone point me towards some websites which can be of
help when dealing with lcd monitor repair.
Schematics, panel reference lists, repair tips, troubleshooting...
Any help would be welcome as google wasn't so helpful.

Cheetah



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Default TFT monitor repair tips


"CheetahHugger" wrote in message
. ..
Hello,

Can anyone point me towards some websites which can be of
help when dealing with lcd monitor repair.
Schematics, panel reference lists, repair tips, troubleshooting...
Any help would be welcome as google wasn't so helpful.

Cheetah


There's two fairly common problems with these which I've had good luck
repairing. One is the backlight CCFL tubes and inverter, and the other is
the power supply. Both of these areas can be fixed using basic
troubleshooting with little flat panel specific knowledge.


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Default TFT monitor repair tips

This is what i am looking for, especially tips and tricks engarding
those inverters.
As well any other tips, i don't wish to service the mainboard but
am sure that i can do a little more then just looking for a smashed
identical screen and swap the board.

Cheetah
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Default TFT monitor repair tips

On Aug 17, 8:54 pm, "Jerry G." wrote:
I don't want to dissapoint you, but component levelservicefor the
LCD and Plasma display's are not normaly supported by any of the
manufactures. They are mainly serviced at the module level only, as
like servicing a PC computer. After warranty, they are usualy
considered not feasible toservice, unless the fault is something
simple.


http://www.justmanuals.com

Fullservicemanualsfor many of these types of displays are usualy
difficult or impossible to obtain. After the warranty periods for most
of this type of technology is finished, spare modules and parts may
not be available unless you can find a scapper unit with good parts.
The exception is if you can find some generic parts that will work.

When factering in the cost of the circuit boards and the laour, the
dropping of the replacement cost, after warrantyserviceis usualy
considered not worth the cost. When troubleshooting and servicing this
type of technology the tools, and instruntation required is fairly
expensive.

If you want toservicethese types of monitors, try to see if you can
negotiate warrenty contract with some of the manufactures. Be
prepaired to invest a fair amount of dollars to get going with this.

Jerry G.

On Aug 17, 1:55 pm, CheetahHugger wrote:

Hello,


Can anyone point me towards some websites which can be of
help when dealing with lcd monitor repair.
Schematics, panel reference lists, repair tips, troubleshooting...
Any help would be welcome as google wasn't so helpful.


Cheetah





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Default TFT monitor repair tips


http://www.justm***************


Did i asked for spam?

Cheetah
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Default TFT monitor repair tips

CheetahHugger wrote:

http://www.justm***************


Did I ask for spam?



Regular, Low Sodium, or Turkey?


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida
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Default TFT monitor repair tips


Regular, Low Sodium, or Turkey?


Regular please, with a pepsi!

Cheetah
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Default TFT monitor repair tips

CheetahHugger wrote:

Regular, Low Sodium, or Turkey?


Regular please, with a pepsi!

Cheetah



No Pepsi! Mountain Dew!!!


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida
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Default TFT monitor repair tips

On Fri, 17 Aug 2007 17:55:58 GMT, CheetahHugger
wrote:

Hello,

Can anyone point me towards some websites which can be of
help when dealing with lcd monitor repair.
Schematics, panel reference lists, repair tips, troubleshooting...
Any help would be welcome as google wasn't so helpful.

Cheetah


At least 8 out of 10 LCD monitors I see have power supply, or back
light inverter problems.

The most common power supply problem is defective caps. Poor quality
caps are finding their way into everything now. The bad ones will
have the tops bulging out, but it's usually best to replace them all
if a few are bad.

The inverters are more complicated to fix. Any number of things can
go wrong. I see bad transformers, shorted transistors, shorted
diodes, and bad caps. No schematics are available and the SMD
components are often not marked in any meaningful way. I have
repaired a lot of them, but it often requires doing a lot of research
to ID parts. Once thing you can check is the tiny surface mount fuse
on the inverter board. When they are blown, about half the time
there's nothing else wrong. Fortunately, the inverter is the one
board that can sometimes be replaced for a reasonable price.
Andy Cuffe




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Default TFT monitor repair tips


No Pepsi! Mountain Dew!!!


Mountain dew cheetah?
LOL

Cheetah
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Default TFT monitor repair tips

Andy Cuffe schreef:
On Fri, 17 Aug 2007 17:55:58 GMT, CheetahHugger
wrote:

Hello,

Can anyone point me towards some websites which can be of
help when dealing with lcd monitor repair.
Schematics, panel reference lists, repair tips, troubleshooting...
Any help would be welcome as google wasn't so helpful.

Cheetah


At least 8 out of 10 LCD monitors I see have power supply, or back
light inverter problems.

The most common power supply problem is defective caps. Poor quality
caps are finding their way into everything now. The bad ones will
have the tops bulging out, but it's usually best to replace them all
if a few are bad.

The inverters are more complicated to fix. Any number of things can
go wrong. I see bad transformers, shorted transistors, shorted
diodes, and bad caps. No schematics are available and the SMD
components are often not marked in any meaningful way. I have
repaired a lot of them, but it often requires doing a lot of research
to ID parts. Once thing you can check is the tiny surface mount fuse
on the inverter board. When they are blown, about half the time
there's nothing else wrong. Fortunately, the inverter is the one
board that can sometimes be replaced for a reasonable price.
Andy Cuffe



Yes, this is what i found out as well, seems we are conned as usual
with bad quality caps.

Cheetah
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Default TFT monitor repair tips

Cheetay,

I have posted my experiences in this area on my website:

http://pkrobot.freehostia.com

-pk


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Default TFT monitor repair tips


Either that's a spampage or it doesn't work.

Cheetah
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Default TFT monitor repair tips

On Aug 18, 1:22 am, "James Sweet" wrote:
"CheetahHugger" wrote:
Can anyone point me towards some websites which can be of
help when dealing with lcd monitor repair.
Schematics, panel reference lists, repair tips, troubleshooting...
Any help would be welcome as google wasn't so helpful.


There's two fairly common problems with these which I've had good luck
repairing. One is the backlight CCFL tubes and inverter, and the other is
the power supply. Both of these areas can be fixed using basic
troubleshooting with little flat panel specific knowledge.


How do you isolate a CCFL/inverter problem without swapping parts?
I have a panel with a backlight that goes out about two seconds after
power on. Transistor/diode junctions all look OK, no visible cap
problems,
tubes have no telltale black bands. Shorted transformer winding,
perhaps?
How to test for that?

Thanks,
TM




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Default TFT monitor repair tips



How do you isolate a CCFL/inverter problem without swapping parts?
I have a panel with a backlight that goes out about two seconds after
power on. Transistor/diode junctions all look OK, no visible cap
problems,
tubes have no telltale black bands. Shorted transformer winding,
perhaps?
How to test for that?



I have a few lamps and inverters that are not in monitors, it's pretty easy
to wire one or the other up for testing without tearing things apart too
much.


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Default TFT monitor repair tips

I use a scanner lamp driver to test individual lamps in the screen.
Yesterday i fixed an inverter that was shutting down, it had a shorted
diode and a damn small one.
Cap problems are not always visible, i use the atlas esr60 meter and
it tells me a lot of caps simply go high esr but don't bulge.

Cheetah
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Default TFT monitor repair tips

On Aug 20, 12:01 am, Andy Cuffe wrote:
The inverters are more complicated to fix. Any number of things can
go wrong. I see bad transformers, shorted transistors, shorted
diodes, and bad caps. No schematics are available and the SMD
components are often not marked in any meaningful way. I have
repaired a lot of them, but it often requires doing a lot of research
to ID parts.


Along those lines, I have a Sampo QPWBGL993IDLD inverter with a bad
transistor (Q8, one of two that drive the transformer windings). It's
an
SC-62/MPT3 package, with 'CF', 'Å', and 'RT' markings. After much
online research, I identified two possible devices that this could be:

Sanyo 2SC3650 NPN, 25V, 1.2A (hFE = 1500 typ)
http://www.ortodoxism.ro/datasheets/..._e/2SC3650.pdf
or
Rohm 2SD2150 NPN, 20V, 3A (hFE = 180-390)
http://datasheets.ru/datasheets/1078...a-2SD2150.html

Which one is it (or is it some other transistor)?

Thanks,
TM

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Default TFT monitor repair tips

On Aug 17, 1:55 pm, CheetahHugger wrote:
Hello,

Can anyone point me towards some websites which can be of
help when dealing with lcd monitor repair.
Schematics, panel reference lists, repair tips, troubleshooting...
Any help would be welcome as google wasn't so helpful.

Cheetah


http://www.justmanuals.com

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