DeLL E152FPc Goes black after a second.

[Jeff Liebermann]

On Thu, 08 Oct 2009 10:51:39 -0700, D Yuniskis
<not.going.to.be@seen.com> wrote:

Understood. My point is that the price/repair point is quickly
moving to make 19" as uneconomical to fix as the 17's have become.

Yep. I just did a quick search using Google Shopping for "19" LCD
monitor". Quite a few refurbished units for $70 to $100. New for
about $120 to $150. Not very economical to repair at $75/hr.

I have a Dell that rotates. But, in order to do so, the display
has to be "up" high enough (so the rotating end doesn't wack
into the tabletop). This places the display too high for me
in my normal usage.

Not mine. However, I made my own out of a swivel plate with detents
as inspired by:
<http://www.instructables.com/id/rotate-or-pivot-lcd-monitor/>
The lazy susan is a bit too crude for me. However, all my office and
home monitors are 4:3, not 16:9. They rotate quite easily. 16:9 wide
screen monitors might seem a bit high, but I've built two of these for
customers and they loved it. One is a script writer and the other a
technical editor, which might explain their interest in portrait mode
displays.

[N.B. I have been told by folks who wear bifocals that even
*my* display height is too high for them to use comfortably;
they end up having to tip their heads too far back to bring
the screen into the correct portion of the eyeglass lens to
focus]

I'm 61 years ancient, wear bifocals, and don't have a problem. That's
because I don't use the bifocals in front of the screen. I'm
fortunate and can still use the cheap "reading" glasses without
correction for computer use. For driving, I need bifocals.

Plug: Cheap prescription glasses:
<http://www.zennioptical.com>

I do a lot of DTP and have found that I can get pretty good
performance out of nearly any "large-ish" display. When
working on prose, etc. I zoom the image to "fit width".
This gives me lots of detail (when you've got 1600 dots
to play with :> ) and enough of the page vertically that I
can see what I am doing. I only look at full page views
when I want to get a feel for the layout of the page,
the location of whitespace, etc.

Well, I've been told that I have no writing ability, no aesthetic
sense, no appreciation of layout styles, and no artistic abilities.
That's a sufficient to avoid DTP and other forms of real work. About
the only layout work I do is some HTML, which is admittedly fairly
badly done. Despite these limitations, I can usually adapt to any
screen size or layout ranging from tiny Netbook and PDA displays, to
projection screens. Getting a full page view doesn't do much for me.
However, waiting a few days and taking a second look usually causes me
to ask "what was I thinking"?

More seriously, I cheat a bit and have two monitors and two computers
on my desk at home. I have a switch that allows me to put both
monitors on a dual display video card on the main machine. That's
very useful if I want a huge workspace. I don't used it often, but
when doing antenna design and 3D modeling, it's quite handy.

A second monitor is invaluable in just about any desktop
(not just DTP) application. It lets you work in one *full*
screen while having another (full!) screen for other uses
(e.g., floating pallets for image editing, "text" that
you are copy/pasting into the actual application, a OCB
schematic alongside the PCB *layout* you are working on,
etc.)

Yep.

(there are currently six 21 inch LCDs
awaiting pats in various states of disassembly... this causes
a fair amount of grief! And, isn't realistic when you have
pets :< )

You haven't seen my office. 700 sq ft, mostly storage and bakers
racks.
<http://802.11junk.com/jeffl/pics/office/slides/office-panorama-2.html>
(scroll horizontally). I wouldn't have room for 6 monitors. In my
case, the danger is not pets. It's visitors. Despite warnings,
visitor always manage to smash into something. No fatalities, so far.

If I did this for a *living*, I would just keep a spare inverter
around and hack it into the "bad" display long enough to illuminate
the display (using a nice "white" test screen) to check for these
"smudges" before investing much time in the repair.

I do that, but only for testing CCFL tubes. I always seem to forget
to test the assembled panels. Thanks for the reminder.

That's the problem. For example, I just bought a DC controller for an
HP LaserJet 4200. Big crack on the formatter PCB. I could send it
back as defective and get another, or just patch the board and be done
with it. I'll probably phone the eBay vendor and see what he has to
offer. That's one of the risks of buying obviously used parts.

Exactly. And, if the cost of return postage becomes an issue,
it might not be economical to even *try* to return it (most
ebay sellers don't consider the threat of a "negative" to be
important; especially if they are selling in volume)

Nope. They just threaten to give me a negative review for daring to
suggest they're selling crap and don't honor their alleged warranties.
However, that's only happened once in perhaps 8 years, so I'm not
worried about retaliation. In this case, I called the vendor, who
indicated that I should try the board despite the crack, and see what
happens. If it fails, he'll still honor the warranty. So, I crammed
it into the HP LJ4200 (about 20 connectors) and it worked just fine. I
slopped some epoxy on the crack and will deliver it tomorrow. No need
to return it.

Only to discover that the inverter's design had been changed
mechanically. Not only had the connectors to the CCFL's
been "rendered incompatible", but the board mounting wasn't
compatible, either!

Yep. Been there and had it happen. It's really ugly inside laptop
LCD displays, where there's little room to maneuver. I just bought a
replacement inverter for a Dell B130 laptop that had exactly the same
part number as the original, but where the mounting hole was moved
about 0.050". I took apart the mounting bracket, filed the hole to
fit and reassembled. 20 minutes totally wasted. Other laptops were
not so easy. I've had to use hot melt glue to secure some inverters.

frown> Would have been better (from a standpoint of my time)
had they *both* been defective! ;-)

On the other foot, I have nothing against cannibalism.

On motherboards, replacing caps is considerably more risky as
the boards are often 4 (or even 6) layers and often don't
have thermal reliefs around the caps. Unless it is a particularly
nice board, I don't bother (you also have no way of knowing if
the high ripple on those power signals hasn't toasted something
else in the design.

Yep. I have a Pace desoldering station with a motorized vacuum pump.
It's strong enough to suck the pad off the board if necessary. Some
boards offer some relief around the leads, while others are so tight
as to defy removal. I have a method to deal with caps that's somewhat
non-conventional. I have a cable cutter, with semi-circular cutters,
that I use to chop off the top of the cap near the base. I then
remove what's left of the base, leaving only two leads projecting from
the PCB. I grab a lead with pliers, heat the joint, and pull them
out, one at a time. Works nicely and much better than the Pace
desoldering station.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[D Yuniskis]

Jeff Liebermann wrote:

On Thu, 08 Oct 2009 10:51:39 -0700, D Yuniskis

Understood. My point is that the price/repair point is quickly
moving to make 19" as uneconomical to fix as the 17's have become.

Yep. I just did a quick search using Google Shopping for "19" LCD
monitor". Quite a few refurbished units for $70 to $100. New for
about $120 to $150. Not very economical to repair at $75/hr.

And their prices continue to fall. So, you fix one only
to find it "competing" with a new, *warrantied* unit for
roughly the same price.

I have a Dell that rotates. But, in order to do so, the display
has to be "up" high enough (so the rotating end doesn't wack
into the tabletop). This places the display too high for me
in my normal usage.

Not mine. However, I made my own out of a swivel plate with detents
as inspired by:
http://www.instructables.com/id/rotate-or-pivot-lcd-monitor/
The lazy susan is a bit too crude for me. However, all my office and
home monitors are 4:3, not 16:9. They rotate quite easily. 16:9 wide
screen monitors might seem a bit high, but I've built two of these for
customers and they loved it. One is a script writer and the other a
technical editor, which might explain their interest in portrait mode
displays.

I'd rather wider. I tried a three monitor setup once and
*loved* it. But, my current machine doesn't like having
lots of video cards :-(

[N.B. I have been told by folks who wear bifocals that even
*my* display height is too high for them to use comfortably;
they end up having to tip their heads too far back to bring
the screen into the correct portion of the eyeglass lens to
focus]

I'm 61 years ancient, wear bifocals, and don't have a problem. That's
because I don't use the bifocals in front of the screen. I'm
fortunate and can still use the cheap "reading" glasses without
correction for computer use. For driving, I need bifocals.

Yes, I think the problem is with folks whose reading and computer
Rx's are different. E.g., I know people with "computer bifocals"
(the near Rx is set for the distance to the screen while the
far is set for "distance") and "regular bifocals" (near Rx is
set for reading with far set for "distance"). Apparently,
trying to read "close up" through the "computer Rx" is where
the problem lies (I once saw a pair of lenses cut with *four*
different regions in each lens -- I guess predating "progressive"
lenses?)

Thankfully, I still only need glasses for distance -- though
reading the markings on some components either requires
bright light *or* a magnifying glass (e.g. reading glasses)
Apparently a consequence of losing "focusing power" with age.

Plug: Cheap prescription glasses:
http://www.zennioptical.com

I do a lot of DTP and have found that I can get pretty good
performance out of nearly any "large-ish" display. When
working on prose, etc. I zoom the image to "fit width".
This gives me lots of detail (when you've got 1600 dots
to play with :> ) and enough of the page vertically that I
can see what I am doing. I only look at full page views
when I want to get a feel for the layout of the page,
the location of whitespace, etc.

Well, I've been told that I have no writing ability, no aesthetic
sense, no appreciation of layout styles, and no artistic abilities.

Ha! Sounds like a career in POLITICS should be right up your alley!
;-)

I deliberately started taking on these kinds of work just to try to
develop those skills. Spelling is sometimes a challenge (esp
when it comes to "doubling the final consonant") but there are
tools to help with that :-/

That's a sufficient to avoid DTP and other forms of real work. About
the only layout work I do is some HTML, which is admittedly fairly
badly done. Despite these limitations, I can usually adapt to any
screen size or layout ranging from tiny Netbook and PDA displays, to
projection screens. Getting a full page view doesn't do much for me.
However, waiting a few days and taking a second look usually causes me
to ask "what was I thinking"?

More seriously, I cheat a bit and have two monitors and two computers
on my desk at home. I have a switch that allows me to put both
monitors on a dual display video card on the main machine. That's
very useful if I want a huge workspace. I don't used it often, but
when doing antenna design and 3D modeling, it's quite handy.

I have my two primary machines attached to a pair of monitors
with built-in A/B switches. So, I can have both monitors
attached to either machine or one monitor on each. I keep the
keyboard for one machine on the work surface and the other in
a "keyboard drawer" beneath. I find this easier than using a KVM
though, at times, I have a hard time remembering which keyboard
to type on! :-/

(there are currently six 21 inch LCDs
awaiting pats in various states of disassembly... this causes
a fair amount of grief! And, isn't realistic when you have
pets :< )

You haven't seen my office. 700 sq ft, mostly storage and bakers
racks.
http://802.11junk.com/jeffl/pics/office/slides/office-panorama-2.html

<jealous> ;-)

I work out of a spare bedroom for "head stuff" and commandeer
appropriate floor space as needed (and usually incur much
wrath in doing so!). I think it helps me keep things from
getting out of control and ending up living in a "cave".

(scroll horizontally). I wouldn't have room for 6 monitors. In my
case, the danger is not pets. It's visitors. Despite warnings,
visitor always manage to smash into something. No fatalities, so far.

Visitors you can at least vent your anger on (even if you do
it privately after they depart). With pets, you really can't
blame them for their actions -- the fault lies squarely with *you*!
<frown>

If I did this for a *living*, I would just keep a spare inverter
around and hack it into the "bad" display long enough to illuminate
the display (using a nice "white" test screen) to check for these
"smudges" before investing much time in the repair.

I do that, but only for testing CCFL tubes. I always seem to forget
to test the assembled panels. Thanks for the reminder.

Well, *I* haven't learned that lesson, yet! :< But, again,
if I was doing this "for real", I would set things up more
efficiently (I repair them for a local charity so I can't
really invest much time/space in this)

Only to discover that the inverter's design had been changed
mechanically. Not only had the connectors to the CCFL's
been "rendered incompatible", but the board mounting wasn't
compatible, either!

Yep. Been there and had it happen. It's really ugly inside laptop
LCD displays, where there's little room to maneuver. I just bought a
replacement inverter for a Dell B130 laptop that had exactly the same
part number as the original, but where the mounting hole was moved
about 0.050". I took apart the mounting bracket, filed the hole to
fit and reassembled. 20 minutes totally wasted. Other laptops were
not so easy. I've had to use hot melt glue to secure some inverters.

Ouch. Owing to my time limitations, I am pretty reluctant about
investing much "special effort" in fixes that aren't relatively
straightforward. If I was *paid* for my time, I might think
otherwise. Or, if the repair was for my own personal use.
Otherwise, if I can't make it work without re-engineering the
fix, it goes in the recycle pile...

frown> Would have been better (from a standpoint of my time)
had they *both* been defective! ;-)

On the other foot, I have nothing against cannibalism.

Of course! I was originally *thrilled* with the idea that I
could make a quick fix just by stealing parts from one for
the other. A real "no-brainer". Hence the disappointment
when I saw the *arbitrary* changes they had made in
manufacturing... :<

On motherboards, replacing caps is considerably more risky as
the boards are often 4 (or even 6) layers and often don't
have thermal reliefs around the caps. Unless it is a particularly
nice board, I don't bother (you also have no way of knowing if
the high ripple on those power signals hasn't toasted something
else in the design.

Yep. I have a Pace desoldering station with a motorized vacuum pump.
It's strong enough to suck the pad off the board if necessary. Some
boards offer some relief around the leads, while others are so tight
as to defy removal.

Exactly. I have actually deliberately laid out some boards
like this to discourage "amateur" repairs. Really obvious
when someone lifts a pad because they weren't prepared to deal
with a board laid out with such fine-line rules...

I have a method to deal with caps that's somewhat
non-conventional. I have a cable cutter, with semi-circular cutters,
that I use to chop off the top of the cap near the base. I then
remove what's left of the base, leaving only two leads projecting from
the PCB. I grab a lead with pliers, heat the joint, and pull them
out, one at a time. Works nicely and much better than the Pace
desoldering station.

I usually find that the thermal mass of the tip I am using
(at the time) is just not enough to overcome any big ground
planes, etc. And, rather than wait for the tip to cool so
I can swap in something larger, I just move on to the next
candidate. :< Always more broken stuff waiting to be fixed
than there is time available to fix it! (and it sure looks
like the current "lack of quality" will be with us for quite
a while!)

 

[JW]

On Thu, 08 Oct 2009 18:06:27 -0700 Jeff Liebermann <jeffl@cruzio.com>
wrote in Message id: <hv0tc55o6p5aumg10q6f2o5hk30qvvijif@4ax.com>:

http://802.11junk.com/jeffl/pics/office/slides/office-panorama-2.html

Those scopes look ancient!

 

[Jeff Liebermann]

On Fri, 09 Oct 2009 05:09:29 -0400, JW <none@dev.null> wrote:

On Thu, 08 Oct 2009 18:06:27 -0700 Jeff Liebermann <jeffl@cruzio.com
wrote in Message id: <hv0tc55o6p5aumg10q6f2o5hk30qvvijif@4ax.com>:

http://802.11junk.com/jeffl/pics/office/slides/office-panorama-2.html

Those scopes look ancient!

They work. There's another pile of scopes at home including some that
are waiting for me to find time to repair:
<http://802.11junk.com/jeffl/pics/home/slides/BL-shop5.html>
Hmmm... that's an old photo that only shows about 1/3 of the pile. I
guess my test equipment collection qualifies as a 1970's technology
museum, but it's quite adequate for what I need. I'm currently
considering a USB oscilloscope, so some of the old scopes may
eventually be retired.


--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Jeff Liebermann]

On Thu, 08 Oct 2009 21:45:11 -0700, D Yuniskis
<not.going.to.be@seen.com> wrote:

I'd rather wider. I tried a three monitor setup once and
*loved* it. But, my current machine doesn't like having
lots of video cards :-(

I bought several ATI 2 port PCIe video cards. The county uses Matrox
video cards in their emergency dispatch center to run up to 4
monitors. However, why stop at 3 monitors:
<http://www.wideview.it/wideview.htm>
<http://www.wideview.it/pictures.htm>

Yes, I think the problem is with folks whose reading and computer
Rx's are different. E.g., I know people with "computer bifocals"

I can see that if they're transcribbling from notes or have to look at
their fingers when typing. Seeing the screen is not a problem because
it's fixed distance. However, the keyboard and copy might be anywhere
between about 12" to 36". That's a good application for progressive
lenses. Learning to type better and purchasing a copy stand might be
alternatives. Fortunately, I can type at about 30 mistakes per minute
without looking at the keyboard, so single vision is adequate for me.

Thankfully, I still only need glasses for distance -- though
reading the markings on some components either requires
bright light *or* a magnifying glass (e.g. reading glasses)
Apparently a consequence of losing "focusing power" with age.

Yep. Same problem. I have a Maglite for exactly that purpose. The
depth of field for my eyes increases when the pupil narrows under
bright lights.

Plug: Cheap prescription glasses:
http://www.zennioptical.com

Well, I've been told that I have no writing ability, no aesthetic
sense, no appreciation of layout styles, and no artistic abilities.

Ha! Sounds like a career in POLITICS should be right up your alley!

Nope. I tried to get elected to the local water board and failed. I
also have some bad habits and strange appearance that apparently
affects my abilities to get elected:
<http://802.11junk.com/jeffl/pics/jeffl/slides/jeffl-wolf.html>
(Give it a few seconds to load).
I also tend to go in circles:
<http://www.LearnByDestroying.com/panorama/jeffl.htm>
(Give it time to load. Then move the mouse around the photo).

You haven't seen my office. 700 sq ft, mostly storage and bakers
racks.
http://802.11junk.com/jeffl/pics/office/slides/office-panorama-2.html
jealous> ;-)

That was when it was clean. I'll post a current photo when I get to
the office in a few daze. Incidentally, I've been at the same
location since about 1990, which might explain the accumulation of
junk.

Of course! I was originally *thrilled* with the idea that I
could make a quick fix just by stealing parts from one for
the other. A real "no-brainer". Hence the disappointment
when I saw the *arbitrary* changes they had made in
manufacturing... :

That's not unusual. If you look carefully, the two parts were
probably made by different vendors (both probably working from the
same drawings but making different mistakes). Manufacturers like to
have a single model number maintained as long as possible, even though
the guts change radically. That's so they don't have a deluge of
credit returns and restocking from their own dealers every time a new
and improved model appears. That's very common in the wireless router
business. For example, the Netgear WGR614 and Linksys WRT54G have 9
and 8 different hardware mutations respectively. Unless you know the
trick, it's almost impossible to tell which version without ripping
open the box. LCD monitors are not that bad, but close. Subtle
variations in model numbers (usual a suffix) indicate radical
variations in vendor and internals.

Exactly. I have actually deliberately laid out some boards
like this to discourage "amateur" repairs. Really obvious
when someone lifts a pad because they weren't prepared to deal
with a board laid out with such fine-line rules...

Never attribute to malice that which is adequately explained by
incompetence.

I have a method to deal with caps that's somewhat
non-conventional. I have a cable cutter, with semi-circular cutters,
that I use to chop off the top of the cap near the base. I then
remove what's left of the base, leaving only two leads projecting from
the PCB. I grab a lead with pliers, heat the joint, and pull them
out, one at a time. Works nicely and much better than the Pace
desoldering station.

Next opportunity, try it my way. Being able to eliminate the
cazapitor as a heat sink, and having access to both sides of the lead,
is a big plus. Even the big ground plane sinking doesn't seem to be
as bad with the mass of the cazapitor gone.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[D Yuniskis]

JW wrote:

On Thu, 08 Oct 2009 18:06:27 -0700 Jeff Liebermann <jeffl@cruzio.com
wrote in Message id: <hv0tc55o6p5aumg10q6f2o5hk30qvvijif@4ax.com>:

http://802.11junk.com/jeffl/pics/office/slides/office-panorama-2.html

Those scopes look ancient!

Good scopes never die! :> I still long for a Tek 454 (which
probably also qualifies as ancient but is more than adequate
for my nominal "analog" needs!). And, I groan when I think
about how many tek probes I gave away over the years :<
(most of my work is digital so I am far more interested in
the "micro hooks/grabbers)

 

[D Yuniskis]

Jeff Liebermann wrote:

On Thu, 08 Oct 2009 21:45:11 -0700, D Yuniskis

I'd rather wider. I tried a three monitor setup once and
*loved* it. But, my current machine doesn't like having
lots of video cards :-(

I bought several ATI 2 port PCIe video cards. The county uses Matrox

The machines that I am currently using are strictly PCI
(i.e., not PCIe, x, AGP, etc.) so I have limited choices for
video cards. And, most of the slots are already full:
- USB2
- Wide SCSI
- Wide Differential SCSI
- Narrow SCSI
- "sound"
- Firewire
so adding a video card (even a dual-headed card) means losing
something else :<

video cards in their emergency dispatch center to run up to 4
monitors. However, why stop at 3 monitors:
http://www.wideview.it/wideview.htm
http://www.wideview.it/pictures.htm

Yes, I think the problem is with folks whose reading and computer
Rx's are different. E.g., I know people with "computer bifocals"

I can see that if they're transcribbling from notes or have to look at

Exactly. If you have written material that you need to consult,
you're screwed. I'm lucky because my interactions are usually
"original works" (so the "source" is in my head someplace)
*or* I can have the "other documents" (e.g., datasheets) open
on another monitor to consult -- instead of having to refer
to paper.

their fingers when typing. Seeing the screen is not a problem because
it's fixed distance. However, the keyboard and copy might be anywhere
between about 12" to 36". That's a good application for progressive
lenses. Learning to type better and purchasing a copy stand might be
alternatives. Fortunately, I can type at about 30 mistakes per minute
without looking at the keyboard, so single vision is adequate for me.

Thankfully, I still only need glasses for distance -- though
reading the markings on some components either requires
bright light *or* a magnifying glass (e.g. reading glasses)
Apparently a consequence of losing "focusing power" with age.

Yep. Same problem. I have a Maglite for exactly that purpose. The
depth of field for my eyes increases when the pupil narrows under
bright lights.

Ah, I never thought of it in those terms!
I have a pair of reading glasses with small LED lamps
attached to each temple. I use them in lieu of a magnifying
glass (much more convenient -- unless you only need to
look at something *once*). If I am in a darkened area
(like trying to read the connector designations on the
back of a PC *under* my work table), then I flip on the
LEDs for more illumination.

To work on boards, I have a 70X (?) B&L stereomicroscope.

Plug: Cheap prescription glasses:
http://www.zennioptical.com

Well, I've been told that I have no writing ability, no aesthetic
sense, no appreciation of layout styles, and no artistic abilities.
Ha! Sounds like a career in POLITICS should be right up your alley!

Nope. I tried to get elected to the local water board and failed. I
also have some bad habits and strange appearance that apparently
affects my abilities to get elected:
http://802.11junk.com/jeffl/pics/jeffl/slides/jeffl-wolf.html
(Give it a few seconds to load).

My browser isn't configured for animations (since those are usually
"ads" -- why waste CPU cycles on something I don't care to see? :> )

I also tend to go in circles:
http://www.LearnByDestroying.com/panorama/jeffl.htm
(Give it time to load. Then move the mouse around the photo).

You haven't seen my office. 700 sq ft, mostly storage and bakers
racks.
http://802.11junk.com/jeffl/pics/office/slides/office-panorama-2.html
jealous> ;-)

That was when it was clean. I'll post a current photo when I get to
the office in a few daze. Incidentally, I've been at the same
location since about 1990, which might explain the accumulation of
junk.

I have found that the adage of junk accumulating to fill
available space is true. So, I severely restrict the "available
space"! (clever, eh? :> ) Living in the DSW means you
can't store anything in anyplace *other* than "living area".
So, that means only "inert" things (cables, mechanical
parts, etc.) can be stored in the garage; everything else
has to fit in the office or under a bed or in a closet.

This makes space a premium. I think there are 10 or 11
computers running here (different operating systems,
purposes, etc.) along with 7 or 8 printers (different
capabilities ranging from "postcard printers" to
"wide format"), three plotters (various sizes), three
different scanners (up to B size) -- plus various other
special purpose peripherals.

You learn to get the most out of everything you have
lest you find yourself needing something *else*! :>

Of course! I was originally *thrilled* with the idea that I
could make a quick fix just by stealing parts from one for
the other. A real "no-brainer". Hence the disappointment
when I saw the *arbitrary* changes they had made in
manufacturing... :

That's not unusual. If you look carefully, the two parts were
probably made by different vendors (both probably working from the
same drawings but making different mistakes). Manufacturers like to

Dunno. The two monitors in question have already been
recycled.

have a single model number maintained as long as possible, even though
the guts change radically. That's so they don't have a deluge of
credit returns and restocking from their own dealers every time a new
and improved model appears. That's very common in the wireless router
business. For example, the Netgear WGR614 and Linksys WRT54G have 9
and 8 different hardware mutations respectively. Unless you know the
trick, it's almost impossible to tell which version without ripping
open the box. LCD monitors are not that bad, but close. Subtle
variations in model numbers (usual a suffix) indicate radical
variations in vendor and internals.

That seems to be particularly true of the Dell monitors
(which is where this thread started)

I have a method to deal with caps that's somewhat
non-conventional. I have a cable cutter, with semi-circular cutters,
that I use to chop off the top of the cap near the base. I then
remove what's left of the base, leaving only two leads projecting from
the PCB. I grab a lead with pliers, heat the joint, and pull them
out, one at a time. Works nicely and much better than the Pace
desoldering station.

Next opportunity, try it my way. Being able to eliminate the
cazapitor as a heat sink, and having access to both sides of the lead,
is a big plus. Even the big ground plane sinking doesn't seem to be
as bad with the mass of the cazapitor gone.

I'll *try* to keep it in mind -- but expect to forget it! :>
(I've been changing the oil in my vehicles for decades and I
always remember to put on the nitrile gloves *after* I am
finished :-(

 

[propman]

Jeff Liebermann wrote:

alternatives. Fortunately, I can type at about 30 mistakes per minute
without looking at the keyboard, so single vision is adequate for me.

LOL! We must have had the same typing tutors!

 

[msg]

Jim Yanik wrote:

Jeff Liebermann <jeffl@cruzio.com

I've
also managed to get electrocuted several times, mostly due to haste,
sloppiness, clip leads, or all the aformentioned.

Not "electrocuted",but shocked.
"electrocution" is to KILL with electricity. Since you're still posting,you
aren't killed. ;-)

Unless he is one of the new fast walking zombies (thanks Two and a Half Men).

Michael

 

On Thu, 08 Oct 2009 13:00:17 -0700, D Yuniskis
<not.going.to.be@seen.com> wrote:

PlainBill47@yahoo.com wrote:

As a rule of thumb, when a monitor has a defective cap, I will replace
the lot of them. As you point out, it's not worth the risk of having
to open the monitor up again.

I prefer Panasonic FM or FC series for replacements. Purchasing from
Digikey, I can redo an entire monitor for under $10, including
shipping. (OK, I seldom replace the 100 ľF 450 Volt cap).

I've only seen one of these "bad" (in about 100 monitors).
Despite the fact that they are often manufacture by the same
company who manufactures the other (crappy) caps on the
board! I guess the ripple currents are not as large (?)
The large (rectified mains filter) is handling 120 Hz ripple (and the

pulses from the SMPS). The filter caps on the secondary are handling
100 KHz or greater ripple. As I understand the problem, the ripple
current will cause heating (duh!), which will cause the ESR to rise,
causing more heating, until eventually a poorly made cap will vent.

The mains filter cap has several advantages - much lower current and
much more surface area to dissipate the heat.

PlainBill

 

[Meat Plow]

On Wed, 07 Oct 2009 16:26:56 -0700, Jeff Liebermann
<jeffl@cruzio.com>wrote:

Weakest link = inverters. Verify voltage source first, forget what
they usually run but a guess would be around 20 vdc?

Now I know why we used to kill off a tech a year in the 2-way biz in
Smog Angeles during the 60's and 70's. They didn't know low from high
voltage. Duz the big fat insulation on the output leads offer a clue?

Maybe voltage 'source' should have been a clue for you. Source as in
the source for the inverter?

Go fuck yourself you pompous fucking asshole.

 

[Samantha]

Took the time today to open that monitor. It went pretty smoothly,
found all the tabs with the help of a small spackle knife. Found the
buldging 1000uf 16v capacitor. Found a replacement on an old board from
a TV and swapped the two. I have the monitor on and the test pattern up
now. Have let it set for about an hour now. Will leave it for a few
more to make sure nothing else happens...

Want to give you all a lot of thanks for the help. I probably would
have stumbled around inside there for quite awhile before I really
figured out how it work.

Knowing how something breaks (common failures) is invaluable when trying
to troubleshoot something.

Thanks to all!!

S.

 

[Samantha]

In article
<4493aa23-cd53-4726-83e6-a7ac62a03820@p23g2000vbl.googlegroups.com>,
Jake <mechanicaljake@gmail.com> wrote:

On Oct 6, 6:19 pm, Samantha <saman...@comcast.net> wrote:
I have a Dell E152FPc Flat screen Monitor 15" that goes black after
about a second after it is powered on.  The Green power light stays on
and the color bar test pattern is there if you stick a flash light up to
it.  

I have never had one of these apart and am not really sure what I am in
for.  Just looking at it, I don't see any obvious way to take it apart.

There are some screws to take off the stand, but after that I am not
sure.

Anybody ever take one of these apart and fix it?

Would greatly appreciate any help.

Thanks so much!!!

S.

I recently repaired 3 E153FP's, which I believe are virtually
identical.

The problem was a 1000uF, 16 volt capacitor, used for the power
supply. It had excessively high ESR, and I am assuming it caused
excessively high ripple voltage which was making the LCD's control
circuitry wack out (that's my very technical description of what I
thought was going on, ha ha). I replaced the same cap on all 3 - It
was easy to identify, about the largest cap on the board, the PCB
material was darkened around it, and the top of the cap was bulged.

Good luck! The 3 I fixed had the exact same symptom you describe, and
have been back in service for about 3 months with no further problems.

-Jake

That is the same same with this one. Found a suitable replacement and
done. Thanks!!

 

[Jamie]

Samantha wrote:

Took the time today to open that monitor. It went pretty smoothly,
found all the tabs with the help of a small spackle knife. Found the
buldging 1000uf 16v capacitor. Found a replacement on an old board from
a TV and swapped the two. I have the monitor on and the test pattern up
now. Have let it set for about an hour now. Will leave it for a few
more to make sure nothing else happens...

Want to give you all a lot of thanks for the help. I probably would
have stumbled around inside there for quite awhile before I really
figured out how it work.

Knowing how something breaks (common failures) is invaluable when trying
to troubleshoot something.

Thanks to all!!

S.
Maybe you might already be aware of this ? but I'll spit it out

in case some one else here may benefit from it.

When ever replacing caps found bad like that, in inverter supplies,
it's a good idea to make sure you use computer grade or some sort of
low ESR types. This is one of the problems that plague these types of
circuits and high ESR just pushing it along faster making the cap run
warm.

 

[Jim Yanik]

Samantha <samantha@comcast.net> wrote in news:samantha-
47B939.17105411102009@news.giganews.com:

Took the time today to open that monitor. It went pretty smoothly,
found all the tabs with the help of a small spackle knife. Found the
buldging 1000uf 16v capacitor. Found a replacement on an old board from
a TV and swapped the two. I have the monitor on and the test pattern up
now. Have let it set for about an hour now. Will leave it for a few
more to make sure nothing else happens...

Want to give you all a lot of thanks for the help. I probably would
have stumbled around inside there for quite awhile before I really
figured out how it work.

Knowing how something breaks (common failures) is invaluable when trying
to troubleshoot something.

Thanks to all!!

S.

Congratulations! it feels good,doesn't it?

--
Jim Yanik
jyanik
at
localnet
dot com

 

[D Yuniskis]

Samantha wrote:

Took the time today to open that monitor. It went pretty smoothly,
found all the tabs with the help of a small spackle knife. Found the
buldging 1000uf 16v capacitor. Found a replacement on an old board from
a TV and swapped the two. I have the monitor on and the test pattern up
now. Have let it set for about an hour now. Will leave it for a few
more to make sure nothing else happens...

Chances are (?), the "replacement cap" was not a high temperature
device (though it might be... depends on where you cound it in
the TV). You really want 105degree (C) devices as they tend
to be higher reliability in these applications. Otherwise,
you'll be replacing *it* soon!

Also, check the manufacturer on the (bad) cap. Chances are there are
a few other caps made by the same manufacturer on that board.
Often best to just replace them all (I realize you are unlikely
to find replacements for all of them on that "TV board" -- but,
if you have to order a hi-temp cap you might as well order
the rest of them if you want to keep the display running for
any length of time) Omit the 400V cap as it seldom fails.

Panasonic FM series caps seem to be a good tradeoff between
cost and reliability. DOUBLE CHECK COMPONENT HEIGHTS/WIDTHS
so you don't end up ordering things that won't fit!

Want to give you all a lot of thanks for the help. I probably would
have stumbled around inside there for quite awhile before I really
figured out how it work.

Knowing how something breaks (common failures) is invaluable when trying
to troubleshoot something.

Exactly. I use repair experiences to guide me in determining
what to avoid when *designing* stuff.