DeLL E152FPc Goes black after a second.

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.

Reply to
Samantha
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Most likely bad capacitors in the inverter (or the bulk supply feeding it). There are a HUGE number of Dell variants so you might be able to find a similar monitor with a different set of "trailing letters" in the model number (I've never bothered to sort out the presumed meaning of all these variations)

Most of these cases snap together. A very small slotted screwdriver and/or one of the "blanks" used to fill an empty "card slot" in a PC is invaluable.

Find a seam between the front and rear halves of the display's case. *Think* about how the two pieces are probably fitted together (i.e., one fits inside/behind the other). Then, slide your tool into the seam and

*gently* pry them apart.

You can usually slide the tool along the seam until you can "feel" where the catches are located. Usually, there is symmetry -- the catches on the left side are placed in the same locations as those along the right edge; ditto for top and bottom (within reason). Also, there tends to be symmetry about the vertical and horizontal axes -- so, if there is a catch

1" down (from the top) the left side, there is probably one 1" *up* (from the bottom) on that side.

Experiment along the bottom -- someplace where your mistakes aren't as cosmetically visible. (remember, plastic deforms easily so you can easily gouge it with your tool).

Good luck!

Reply to
D Yuniskis

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

Reply to
Meat Plow

Thanks, am fighting a really bad summer cold right now and am not really up to messing with it.. But in the next day or so I will probably feel well enough to take a crack at it...

Appreciated everyones input!

Reply to
Samantha

The LCD backlighting inverter has died. Everything else is probably just fine. The really tiny inverters are tricky to repair as a shorted turn on the xformer will usually blow up all the switching FET's. However, this one is big and easy to work on. I still suggest replacement. Tear apart the monitor and get the part number off the LCD inverter. Then search eBay and Google for a scrap replacement. One of these looks right: $40. $30

Bulging and leaking electrolytic caps are the most common problem. Look at the board and you'll see about 8 electrolytic capacitors. If they're even slighly bulging, they're bad. I'm lazy and replace them all rather than trying to figure out which ones are blown. However, with LCD inverters, the switching FET's are also commonly fried. If replacing the caps doesn't work, I suggest just buying a replacement board..

Ummm.... you've heard of Google perhaps?

Lots more when searching for "LCD monitor repair".

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# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
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Reply to
Jeff Liebermann

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?

Try about 500-700VDC output.

The frequency range is also a problem. These bests run around

30-70Khz which is often beyond the upper frequency range of the typical DVG (Digital-Volts-Guesser). I'm not sure if the high frequency or the high voltage did the damage but I've killed at least 2 cheapo (Harbor Freight) DVM's measuring LCD inverter output. I've also managed to get electrocuted several times, mostly due to haste, sloppiness, clip leads, or all the aformentioned.
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# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
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Reply to
Jeff Liebermann

Most of the monitor repair sites are nothiing more than an attempt to sell an overpriced book 'How to repair LCD monitors'.

This specific problem is often referred to as the 'two seconds to black' failure. A quick explanation of the operation of most inverters, and the failure: The inverter has a controller IC that generates the signals that drive the transformers AND monitors the voltage and current outputs of the inverter. Usually the start up sequence consists of driving the CCFL backlights at full brightness for several seconds, then beginning to monitor the output voltage across and current through each CCFL. If the output voltage is too high or too low, or if the current is too high, for any CCFL the controller will shut down.

Possible causes of this problem include bad CCFLs, a shorted transformer, breakdown of insulation in the wiring, or bad components in the monitoring circuits. The Dell E152FPc and related models use an unusual design in the inverter driver; a bad transistor can also cause this problem. And yes, bad capacitors could also be responsible.

This monitor also combines the inverter with the power supply. This makes replacement difficult unless you can obtain a non-working identical monitor inexpensively. Buying through eBay is usually impractical. The cost of shipping is prohibitive.

Rather than spending the time and money to repair a 15" monitor in the USA I usually suggest watching the local Craigslist and Freecycle sites for somone giving away 'dead' LCD monitors. Currently I am using a 23" wide screen monitor I purchased for $15, and repaired by replacing ALL electrolytic caps at a cost of $7. My lates acquisition was a 19" Dell which had a broken power button. Not only was it a simple repair, the donor DELIVERED it!!!

One site I STRONGLY recommend is

formatting link
They have extensive discussions on repairing many LCD monitors, including this one. Registration is required to post, but is free.

PlainBill

Reply to
PlainBill47

Jeff Liebermann wrote in news: snipped-for-privacy@4ax.com:

I think he was talking about INPUT DC being ~20VDC

Because they are only 1 Meg input Z. I took one apart to check it,was debating redoing the divider to 10MegR total.Also,the AC section will not handle freqs over 1 Khz.

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

BTW,you can make a nifty HV probe for a 10Meg DMM by using a string of

22.5Meg 1% metal film R's to make 90 MegR,and putting it inside a plastic tube like an old tuning tool,solder to a 6-32 screw and threaded 1/4" hex spacer,a wire lead with banana plug on the other end,and use an old TEK 500 series probe hook-tip,or other TEK accessory tips. Makes a nice 10:1 probe,and 100 MegR doesn't load the HV supplies so much.

I've used mine for a couple of decades.

--
Jim Yanik
jyanik
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Reply to
Jim Yanik

I had one of these that did the same thing yours is doing. I replaced a couple of transistors in the power supply. Here is a link to the disassembly gude (with lots of pictures) to help you get it open:

formatting link

I used an old credit card to open the sides. A metal screwdriver will chew up the plastic and deform it too much.

Thanks.

Remove the BALONEY from my email address.

----------------------------------------------------- Matthew Fries Minneapolis, MN USA snipped-for-privacy@baloneyvisi.com

"Quit eating all my *STUFF*!" - The Tick

Reply to
Matthew Fries

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

Reply to
Jake

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

Reply to
Jake

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

Reply to
Jake

Some random comments.

True. However, the OP appears to be a beginner and an overpriced book might be a good start. Some others just sell parts:

I question whether it's worth the time and effort to repair a 15" LCD monitor, but this sounds like a personal repair job, not a business. It takes me about an hour to tear apart a monitor, replace all the cazapitors, reassemble, and test. At $75/hr, that exceeds the value of all 15" monitors making commercial repair uneconomical even if the parts were free. Anything that keeps it out of the eWaste pile is probably justifiable.

Not that unusual. This one has two boards, power supply + LCD supply, and a logic board. I think the PS is made by BenQ, but I'm not sure.

Does $20 plus $6 shipping seem prohibitive for do it thyself?

I buy quite a few parts and pieces on eBay. Most are fair prices. A few times, I get cheated.

Nice. I have about 10 such monitors hidden in the closet waiting for me to find the time to raise them from the dead. Most are backlighting or power supply issues. Most were customer "upgrades" where they wanted a newer bigger monitor. I use them as loaners when working.

Nice. Thanks for the analysis and the links.

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Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
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Reply to
Jeff Liebermann

Agreed. I stopped repairing 15's quite a while ago. Then 17's. Now I am getting ready to give up on the 19's (except for wide screen format monitors). They tie up a lot of work space and prices have fallen such that you can buy (economy) versions of even the larger sizes for less than what it costs in time and materials to fix (and not have to deal with the possibility of discovering the screen is "smudged" after you've made the repair)

There are lots of businesses/individuals that will harvest bad monitors for parts (display panels, lamps, etc.) so you should be able to find a non-landfill outlet for your unwanted units. Heck, there are folks still salvaging CRTs!

Just make sure that you don't end up with a "pull"... :>

Reply to
D Yuniskis

Dell has subtle variations in these monitors -- none that I have been able to *quickly* identify (at least not enough that I could open one and determine which model it was just by examining its contents!)

The PCB darkening is usually from the nearby switching transistor. When replacing the cap(s), select high temperature devices (105C) from "reputable" manufacturers (I like panasonic). You want a low ESR cap on most of these applications -- something "designed for switching applications" (I like the FM series as a reasonable cost/performance point). Note that you can also purchase different *grades* of "low ESR caps". So, if you are repairing a particularly "cherry" monitor for your *own* use, you might opt for something rated at ~10,000 hours (instead of ~5,000).

Also, pay careful attention to the *height* of the component! I've been bitten by components that were just a bit too tall to fit back into the case (*with* the metalic shield installed). Lead spacing is also a concern but usually something you can work around.

It probably wouldn't hurt to examine the other caps on the board for "likely future failures". Certain manufacturers tend to have lots of early failures (I joke that "Xom" in the name means "gonna crap out soon"). Since most of the "cost" of the repair is getting the unit apart and then back together, the extra time and expense to replace all likely candidates seems justifiable.

Reply to
D Yuniskis

Not exactly. I'm finding a substantial demand for 4:3 aspect ratio LCD monitors. Anyone dealing with vertical page oriented text finds that the height really matters. A 16:9 LCD is fine for watching DVD's, but a real challenge when doing desktop publishing or document preparation. In the past, LCD's would rotate to a vertical position, but that seems to be a feature missing in most 16:9 monitors. I've had numerous calls for people looking for 4:3 monitors. I can usually find a few new 4:3 monitors on NewEgg and TigerDirect, but those will eventually dry up. So, I save the good ones (19" or bigger) and just wait for the phone calls.

Yep. However, I don't let them hog the bench space. I have some conveniently sized cardboard boxes that fit LCD's vertically. I also have some anti-static foam bags for protecting the screen.

Good point about screen defects discovered after the repair. That hasn't happened too often. What I see is water damage near the bottom of the LCD caused by compulsive screen cleaners. Also, it is easy enough to apply voltage to the CCFL backlight bulbs after you tear it apart to see if there are any cracks or damage.

Yep. They want to buy the scrap by the ton. Very few will buy untested scrap electronics because there's no way to know if it will work when resold. I do some trading with such vendors, but I always have to guarantee (100% refund) everything we sell each other.

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.

Where I get into bigger problems is buying replacement board for products that have a manufacturing related problem. If one board is sick or dead, it's highly likely all the boards will be in the same condition. I had to deal with a motherboard that was just too much work to replace all the bad caps. However, it was obvious that all the replacement boards selling on eBay had exactly the same problem because all the vendors listed their boards as no-return.

Caveat emptor.

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Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
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Reply to
Jeff Liebermann

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.

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.

[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 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.

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.)

Most of the displays I've fixed have too many "things" hanging off of them (cabling to speakers or pushbuttons attached to the front bezel, etc.). Plus, the *stands* don't store well (bulky). Living room floor works well -- but only for a limited number of displays! :> (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 :< )

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.

Ah! I've not seen that! I should start looking more closely.

We've found folks who will gladly take the (known to be defective) LCD monitors that I won't bother to repair. I think maybe $10 or so per display (which is pretty good considering "general eWaste -- from which the plastic and metal cases haven't been removed -- sells for much less than $1/pound)

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)

Yup. This is a double-edged sword; it can also be a *boon* as you fix *one* and you know how to fix them *all*. I ran through a few dozen ViewSonic LCD monitors in a matter of a few days just by making the same repairs on each of them.

What I find more frustrating is when a manufacturer changes design within a particular model. I recently had an "identical" pair of 17" HP LCDs. Since 17" is below my threshold for repair, I only quickly looked at them: one had a bad inverter, the other had a bad *display*! OK, this is a real simple fix -- just cannabilize the two to build *one*.

After tearing (literally) the first one apart to salvage the inverter (hey, the rest of the display is scrap so why bother being careful with the disassembly?? :> ), I *carefully* disassembled the second unit (the one with the good screen) to remove and replace *its* inverter.

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!

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

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.

I'm just now re-cap-ing the power distribution boards (allows redundant power supplies to coexist) in some Dell servers. But, the boards in question are relatively low-tech so I don't fear damaging them -- or the other components on them. And, the caps sit on the outputs of the power supplies so they are somewhat "redundant".

Yeah, its always amusing to see how they act as if they don't *know* anything about the board(s). As if "untested" meant "Gee, I haven't had time to check them" whereas what they really mean is "I didn't BOTHER to test them cuz I'm pretty damn *sure* they're crap!" :-/

Reply to
D Yuniskis

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 µF 450 Volt cap).

PlainBill

Reply to
PlainBill47

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 (?)

Reply to
D Yuniskis

Just want to extend my thanks to all those that answered my post. Didn't find much online when I went and searched for it. This is the first time I have had had one of these apart and didn't really know what to expect. It belongs to my aunt and I said I would take a quick look at it.

The bad cap list was a good tip, really appreciate that, as well as the PDF on how to disassemble the monitor.

Tomorrow is a pretty full day for me so I hope to be feeling up to pulling this apart by saturday.

Thanks again.

S.

Reply to
Samantha

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