Sources for LCD Inverter repair tutorials?

P

prc1

Guest
I have a couple of LCD monitors (Apple 21" and 23" Cinema displays,
Hitachi 17") that have bad inverters. I know these things vary widely
in design, but I wonder if there's a good site/sites that teach about
how inverters work and how to troubleshoot and repair them?
** To respond, remove the crap from my addy... **
 
prc1 wrote:
I have a couple of LCD monitors (Apple 21" and 23" Cinema displays,
Hitachi 17") that have bad inverters. I know these things vary widely
in design, but I wonder if there's a good site/sites that teach about
how inverters work and how to troubleshoot and repair them?
** To respond, remove the crap from my addy... **
Click to expand...
I saw an 'instructable' regarding replacing many inverters with a
generic unit. Try this search link:
<http://www.instructables.com/tag/?q=backlight+inverter&limit%3Atype%3Aid=on&type%3Aid=on&type%3Auser=on&type%3Acomment=on&type%3Agroup=on&type%3AforumTopic=on&sort=none>

Since then, inverters have come down in price. Do an eBay search for
your unit and you might find one cheaply enough to make repair uneconomical.

jak
 
"jakdedert" <jakdedert@bellsouth.net> wrote in message
news:hmm_k.4466$UI2.3085@bignews6.bellsouth.net...
prc1 wrote:
I have a couple of LCD monitors (Apple 21" and 23" Cinema displays,
Hitachi 17") that have bad inverters. I know these things vary widely
in design, but I wonder if there's a good site/sites that teach about
how inverters work and how to troubleshoot and repair them?
** To respond, remove the crap from my addy... **

I saw an 'instructable' regarding replacing many inverters with a generic
unit. Try this search link:
http://www.instructables.com/tag/?q=backlight+inverter&limit%3Atype%3Aid=on&type%3Aid=on&type%3Auser=on&type%3Acomment=on&type%3Agroup=on&type%3AforumTopic=on&sort=none

Since then, inverters have come down in price. Do an eBay search for your
unit and you might find one cheaply enough to make repair uneconomical.

jak
Click to expand...
In general, there are only a few things that fail on them - fuses which may
not look like any fuse you would immediately recognise, transistors (often
surface mount, but can be traditional thru' hole), transformers (some
available, but most not) and the occasional output capacitor. You can find
most of these things with a simple multimeter, but as Jak says, there are
many places selling backlight inverters for both TV and monitor
applications, so unless you are repairing an original just for the fun and
experience, it's often more cost effective to just replace the whole board.
Be careful when playing with them. Although not particularly dangerous, they
can give you a nasty little 'bite' when they are operating ... :)

Arfa
 
On Fri, 05 Dec 2008 10:18:23 -0500, prc1
<prc1CRAP@woh.CRAPrr.comCRAP>wrote:

I have a couple of LCD monitors (Apple 21" and 23" Cinema displays,
Hitachi 17") that have bad inverters. I know these things vary widely
in design, but I wonder if there's a good site/sites that teach about
how inverters work and how to troubleshoot and repair them?
** To respond, remove the crap from my addy... **
Click to expand...
An inverter boosts the voltage up to thousands of volts for the cold
fluorescent backlighting of the panel. You can look up the principal
by doing a web search for dc-dc inverters. Personally I wouldn't mess
with repairing them unless the device was my own or a friends and even
then I would look first for a OEM replacement.
 
are you sure it's the inverters? These Apple monitors have
relatively studly inverters and they drive the tubes quite hard.
More often the tubes have plain worn out.

As is often the case with Apple stuff, you can't just fit in a generic
replacement.

They have custom brightness signals and lamp-out feedback signals that
have to be just right.
And the repair manuals are mostly useless as they don't give any
useful details.
 
On Sun, 7 Dec 2008 10:46:40 -0800 (PST), Ancient_Hacker
<grg2@comcast.net> put finger to keyboard and composed:

are you sure it's the inverters? These Apple monitors have
relatively studly inverters and they drive the tubes quite hard.
More often the tubes have plain worn out.
Click to expand...
Studly inverters tend to do that. :)

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
 
On Dec 7, 10:46 am, Ancient_Hacker <g...@comcast.net> wrote:

They have custom brightness signals and lamp-out feedback signals that
have to be just right.
And the repair manuals are mostly useless as they don't give any
useful details.
Click to expand...
Yep, and that's because the inverters are considered safety-critical
because of the high voltages. No Apple tech will try to 'repair' one,
just replace. Replacements aren't terribly expensive,
but only a certified program-subscribing Apple affiliate can
buy them from the Apple warehouse.

Either find an Apple-sanctioned repair shop, or ask Apple about
mail-in repair. If there's any chance the displays are under
warranty, asking Apple is a good idea, anyhow (they track
warranties by serial number, regardless of owner).
 
Thanks to all for your input! The monitors are mine, and I thought
this might be a good learning experience to attempt a fix since
flat-screens are everywhere these days.

I found an LCD repair supply company (lcdparts.net) that makes a
redesigned inverter for at least one of these monitors--at about $130
a pop. THese would certainly be cheaper and less expensive to acquire
than an original Apple unit.

I've got a smaller project I'll attampt first: a Brookstone 7" digital
picture frame (no OEM info available, unfortunately) whose backlights
blink on and off about once per second. As far as I can tell the main
CPU module works well as it loads and displays the pics off a memory
card just fine.


On Fri, 05 Dec 2008 10:18:23 -0500, prc1 <prc1CRAP@woh.CRAPrr.comCRAP>
wrote:

I have a couple of LCD monitors (Apple 21" and 23" Cinema displays,
Hitachi 17") that have bad inverters. I know these things vary widely
in design, but I wonder if there's a good site/sites that teach about
how inverters work and how to troubleshoot and repair them?
** To respond, remove the crap from my addy... **
** To respond, remove the crap from my addy... **
Click to expand...
 
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