Dell W5001C 50" plasma fix

My buddy's Dell 50" W5001C plasma television conked out one day so I set out trying to fix it. The TV is about 4 years old, and it is out of warranty. Even the three year extended warranty that was offered for $1000 at the time of purchase would have done no good. (Remember when TV's used to last 20 years?) With no recourse for repair through official channels, what is one to do?

"So what are my options?"
1.Fix it at a TV repair shop
Calls to television repair shops produced a range of estimates, i.e. $300 for an on-site consultation and no guarantee of repair. Shipping or transporting the TV to a repair shop could could add insult to injury as it is quite large and might be damaged even further during shipping.

2.Buy a new TV
With new plasma TVs costing about $1000+ for a similar model, it's a tough call between getting the old one fixed or just purchasing a new one. If repairs are more than $500, you'd be better off just chucking the old one and buying new. Since the Dell wasn't smoking or on fire and looked like it was still in very good condition, throwing it away seemed like a waste.

3.Take it apart
While my buddy contemplated what he wanted to do (see options 1 and 2 above), I resolved to just take the dang thing apart to see what I could see. I'm fairly electronics savvy and I love taking things apart, so this was an opportunity not to be missed.

The Bottom Line
Long story short, a $1.09 part took down a $4000 television.

Disclaimer:
The information contained herein is only a journal of my experiences. It is not meant as a tutorial for someone else to fix their own TV. If you use it as such, you do so at your own risk. Don't blame me if you destroy your TV or get hurt in the process. With that said, please continue reading....

Step 1 Symptoms

1. Blank screen
2. TV still powers up, blue led lights up, and relays click at turn on
3. Sound still works
4. Picture may come back for hours at a time but not reliably
5. Picture may appear for a split second when turning off.

How it happened
It all started one day when I went to turn on the TV and, while the power LED lit up and the power relays clicked as usual, the screen was blank. I thought it was on the wrong input so I used the controller to switch inputs but the on-screen menu would not show up either. The sound, however, was working so it was definitely on the right input already. I left the TV on for a while and after a couple minutes, the picture magically appeared! Great, it just needed to warm up I thought. After being left on for a couple of hours however, the screen went dark again. The TV was basically unusable because turning on the TV would usually result in just a dark, blank screen. Since the sound continued to work, I suspected something to do with the power supplied to the plasma screen proper.

Comments

[TJNoffy]

This is a couple of years after the fact, but I just repaired my W5001C and I thought I'd share what happened...

Turned on the TV last week and no Dell logo splash screen or any other video. No audio either. After a couple of tries, the set came on and worked for a few days. Did this again a few days later. Finally the picture and audio died while watching it. The set also didn't respond to the remote (power on/off).

Thanks to this great instructable, I learned to check the voltages on the power supply. All were within specs except the 5v which measured at 3.0v - 3.5v.

I didn't think that the 5v being off would cause the loss of video, but could explain the lack of response to the remote by the logic circuitry.

After reading this: http://blog.coppelltvrepair.com/2010/10/dell-w4201c-hd-powers-on-off-no-picture.html

...I checked the two 2200uF 10v caps shown at this link. They were bulged at the top, and looked to be part of the 5v circuit.

Spent under $3 to replace the two capacitors. Set fixed!

[TJNoffy]

And by a couple of years after the fact I mean a couple of years after mr12volt posted his experience. The above just happened to me...

[fvxtech]

mr12volt,

So I thought I had the same problem with my tv as the one you described, however after replacing the ic I still experience problems. At first I thought it was working correctly however I think it must have been a coincidence. Ive checked the voltages and everything seems good except the 5v. After having the tv unplugged I read from around 3.5V all the way to 4.1V. The tv seems to work if the voltage does build up over 4.2 as sometimes it does. For the most part it doesn't seem to buildup from 3.5V to 4.2V. On pin 8 of U661 i read 4.98V which I believe is correct as Vref of the IC is suppose to be 5V after reading the datasheet on the uc2843. I had originally swapped out U501, and I ordered 2 extra IC's as they are only 1.23 cdn. So U501 and U661 both have UC2843B in them rather than the orignal KA3883's. ZD611 reads the exact same as the 5V output (after buildup stays around 4V) so I believe they are electrically connected, although I have not traced out the PCB. Would you think that the zener is bad? possibly pulling the 5v down to 4V? Any suggestions would be greatly appreciated, I don't have an isolation transformer to work with here only a DMM. I do know electronics, however without a schematic of this I'm finding it very difficult to troubleshoot. Thank you very much for the instructable, very well written.

[TJNoffy]

@fvxtech - Did you every resolve the 5v and D3V3 issue? I'm having the same in my W5001C. I'm about to replace the two 2200 uF caps that are notorious for bulging/failing, and they look to be in the low voltage circuit of the power board. Just curious if you found anything else. Thanks

[mr12volt]

 tcosman,
First of all, please check back with us if you ever work out the problem.  I don't think I can be of too much help since I don't have a schematic either.  BUT! You have something almost as good as the schematic, the board itself!  The board is only two layers so tracing the circuit isn't too bad.  Use the DMM on continuity mode to track down traces that disappear under large components.  Gradually you'll be able to build up enough of a schematic to figure out the topology of the 5V circuit.  If you know electronics, you should be able to tell roughly what is a resistor, capacitor, transformer, diode, and MOSFET switch.  The board is very well marked by its silkscreen and most of the symbols are pretty much there for you.  They're even marked on the backside too! Brilliant.

I'm kinda curious about the 5V and 3V circuits myself.  I never looked closely at the digital logic voltages because that wasn't my problem at the time but now I wish I had.  Many people seem to experience problems with them.  I'd like to know the type of switching regulators used to produce 5V and 3V , if they work off the ~400V rail just after the diode bridge or the +17V DC rail, which IC is the control IC for them, and if they are normally powered when the digital board is not plugged in to the power supply.

Lastly, which 5V rail are you having problems with, the D5V or 5Vstb?

[whitby905]

I'm having the same problem as manuts, voltage problem isolated to Vscan. I measure a constant fluctuation which jumps anywhere between -50 to -175 (or so) somewhat like -50, -166, -75, -175, -80....continuous in fraction of seconds. NO screen change at any time, just black. Kudos to the brilliant people here!

[mr12volt]

It sounds like the controller for the Vscan voltage has become unstable or is not being supplied with enough voltage to maintain regulation. Unfortunately I am not in possession of this TV anymore so I am of limited help. Is there anyone here with a similar Vscan problem located near the Boston area? I wouldn't mind doing a house call to get to the bottom of this one. If so, message me via Instructables. Also, can anyone shed light on the mentions I've heard of certain problems being fixed by replacing some of the electrolytic capacitors? Which caps? What specifics problems has that solve? An unstable voltage regulator chip could be affected by not enough capacitance on the input or output. This is why I bring it up. Electrolytics do degrade over time.

[whitby905]

Thanks for your reply mr12volt. In regards to the e-caps I can tell you that audibly (very faint) there appears to be some relationship to the fluctuation of the voltage...meaning that I can hear the cap altering buzzing with the voltage changes. I also found that if I press the input button on the remote I can hear the buzzing increase in volume (amplitude) until it defaults back to whatever input is active (after about 5-6 seconds) then back to the previous buzzing. These are the large case caps in pair closest to the Vscan circuit flow, before the test point.. I'm going to source new e-caps to change out although they appear to be in good shape visually. If I can find someone to check the e-caps I can further determine if that is my problem.

[mr12volt]

whitby905, Are you sure the buzzing is coming from the capacitors? It is more likely that the buzzing is actually coming from the transformers. The current pulsing through the transformers produces a changing magnetic field causing an alternating constriction in the coils of the transformer windings. The magneto-mechanical constriction and relaxation produces the buzzing sound, a useful diagnostic tool. One is able to audibly tell if there is some sort of intermittency in the transformer circuit by listening for these audible changes. My method of attack was to find the control IC (hint:look for the DIP parts) and poke its pins with my multimeter while listening for audible changes. This is VERY risky however (and slightly disconcerting when the buzzing jumps in volume or frequency). If your hand slips, the multimeter probe tips can short things out and cause more damage. I like to set the probes in position with the TV power off, then turn the power on and read the voltage off the meter. Less chance of disaster that way. Look up the datasheet for the control IC and compare the voltages you recorded for each pin to what they should be according to the datasheet. This takes a bit more advanced knowledge, however, feel free to post your results on this forum and we'll try to help. I wouldn't immediately suspect the electrolytics as the cause for any problems you are having unless there is some other evidence that points to their failure. Pressing the input button on most tv's causes some changes in the audible buzzing so I wouldn't necessarily label that as cause for concern or even unusual. It sounds like you're doing some excellent investigative work. Keep poking around. The more you play with it, the better chance you have of stumbling upon the solution. Keep us updated. p.s. Sorry for the late reply, I've been on holiday since July 7th.

[whitby905]

mr12volt, Thanks for your reply and I hope you had a good holiday. It seems like this project is evolving or possibly devolving depending how you look at it. Upon further testing the voltages are ALL to spec...the earlier Vscan measurement may have been incorrect due to the pressure applied at the test point from the probe??? It is within spec and not jumping. I have found the data sheets for the IC's and am going to check values, but upon further investigation I've found that the controll board (directly behind the input board) there is 2 green LED's near top right of board that the left is on solid and the right is blinking. I don't know if that has any meaning or is an indication to my problem but I'm trying to find that out. Currently when powered on the set still gives the slight audible relay click and (your right) transformer buzzing, power indicator LED (blue) on, but no action from the pannel itself...nobody home. Any further thoughts?? I'll let you know about the IC check.

[mr12volt]

When the TV is off but plugged in, one of the green LED's should be lit. I don't remember what the other LED does when the TV is turned on but blinking seems reasonable. If all the outputs on the power supply are within spec, the problem may not be the power supply. Don't bother checking any of the IC's on the power supply if this is the case. If the output voltages are good, the IC's are doing what they should. (You may want to triple check the voltage testpoints however, just to be sure.) The TV has plenty of other electronics to go wrong. Specifically I've heard many people needing a new Y-Sustain board. Unfortunately I don't know exactly what this is (again, my experience is limited to this one power supply defect.) Basically, if it's not the power supply, it is either the input board below the power supply or one of the plasma drive boards which are flanking the power supply on either side of the TV, or the plasma screen itself. These are all much more difficult to work on than the power supply. They are more highly integrated boards. Make sure the power supply is okay, and if it is, then you may have to bite the bullet and either take it to a TV repair shop or buy a new TV. If you buy a new TV, I suggest you sell the working parts for this Dell on eBay. From the sound of it there are plenty of people who could use them.

[whitby905]

mr12volt I believe we have diagnosed the patient…it appears that the Y-Buffer (lower) which is the long 2 piece PCB flanking the left side of the screen is the problem. I decided to look deeper since the voltages on the power section registered within spec. After a deep visual inspection with magnification and good lighting that yielded no visible results, I started to smell around (using a paper towel roll that just happened to be within reach, so as not to bump my nose into any high voltage parts), I noticed a distinct electrical odor from the left-bottom side. I removed the Y-Buffer and looked to the back of the PCB and voila… there was a short in the solder pattern. It was possibly caused by the heat generated in that region that made the board shift to touch the aluminum case, although there are white plastic standoffs to prevent that, there is not one near the problem location??? So I think that I’ll sign the donor card and allow other Dell’s to live…e-bay it is. I must thank you mr12volt for your original posting which ultimately got me through to experience this small triumph.

[TJNoffy]

Whitby905 If you still monitor this, what were your symptoms? No picture at all?

Also did you have to pull the board into which the Y-buffer card is plugged in order to remove it? Seems to be a post in the way preventing me from unplugging it from the larger board.

I have no picture, but power light in power button lights and relays click. Unit doesn't shut itself off. Green LEDs on PCBs are on solid. All PS voltages are close with my old analog multimeter.

Thanks!

[chuckbox]

What a great set of instructions. I have followed these to the same discovery on my tv.. My lower Y-board has the same burned area as above. Were you able to buy another Y-board or did you scrap the tv? Any ideas

[mr12volt]

whitby905 and chuckbox, Do either of you have your dead Y-Buffer? I would like to photograph and disassemble it, and perhaps publish some detailed information on this second failure mode.

[whitby905]

I still have it. Let me know what you want and I'll do my best.

[whitby905]

Screen is gone but not before I removed the tuner, controller and power assemblies. I'll ebay it at some point soon. Good work everyone. Great site here.

[bdkennedy]

Wanna buy a Dell-W5001C-50?

Hi. I have a Dell-W5001C-50 and i believe it has this same problem. Powers on, blue LED on, relays click. I don't have the expertise to resolve and travel 75% of the time so it's tough to repair.

I'm open to a good deal. Make me an offer? No shipping. pickup only SF Bay Area, CA.

bk

[kmaguire1]

Any point in checking/changing the Caps inbetween the two silver things? Another post said those go bad, or will go bad.

My issues is close, but after 5 mins or so my picture comes up. i tested the VAs and a few of those, and they seem fine. Do you still think it could be the 501 chip?

[Lez1pyt]

How can an ordinary lay person do this or can they do this It seems very difficult

[mr12volt]

Lez1pyt, You are correct, this instructable IS written at a fairly high level and is mostly intended for an audience with some electronics and soldering experience. However, I tried to explain in step 1 that this is simply a journal of my own experience fixing a plasma TV and should certainly not be attempted by everyone. The real value in the instructable is the information about the symptoms and diagnosis of one particular failure mechanism. While most people do not have the experience necessary to diagnose the problem, many will know somebody who has some mechanical ability and soldering skills. My hope is that, with the information I have given, the owners of these TVs can seek out a friend with the modest experience necessary to perform the fix. The hard part is not de-soldering the defective component. It's knowing which component is defective.

[lnolan1]

Mr12volt

You worked on a dell 50inch I have a dell 42 inch with much of the same symptoms.
For two weeks the TV would work good all day long, turn off, turn on, good picture
But my wife would wake me up in the morning with ( The TV won't turn on) I'd get up and mess with it. then unplug it, and plug it in. and it would them turn on and work all day alright. Then one day no more TV, The lights were on but the Walton's won't home. I'm not as good as you in electronics. But I do solder and de-solder with what I have, I diagnosis with guess work, sometimes I get it right, sometimes no. there are many similarities with the 50 and the 42 But the the power board maybe a little different from what I can see by your pic's Do you thank that the chip you replaced cloud be the same? if there is an U501 in the 42 would it be the same? do the symptoms sound the same to you? Give me a little help if you would.
Thanks
Lyn

[mr12volt]

Lyn,
Your television's symptoms sound similar so this could very well be the same problem. It's possible that the power supply will have the same reference designators for it's components so look for U501 first. If nothing matches, look at all the DIP parts to see if there is one with 8 pins that reads "KA3883". There won't be too many DIP parts. Use a flashlight and magnifying glass if the printing on the chips is hard to read. If you find a match and are up to the challenge, I say go for it.

[lnolan1]

Thank you much Mr12volt
After reading your reply, I removed the back for the first time. I have just one more question before entering the Lions Den. My power board is the same shape as yours but thats where similarity ends. The components are so many you can't even see the board. and the arrangement of these Components defer from the 50 inch.
in all ways. except for one! There is only one 8 pin IC on the entire board It is marked as IC8003 The chip it self has K436 TOP223PN 30309C This chip is in the Exact spot as your KA3883 And this is a Samsung board.

So My Question is! (Do you think? Could it be?) Await your reply

Thanks
Lyn

[mr12volt]

The TOP223PN is totally different from the KA3883.
http://www.powerint.com/sites/default/files/product-docs/top221-227.pdf
It is NOT interchangable. Since the power supply board is so different, this isn't likely to be the same problem. That doesn't mean you should give up though! If you know how to use a multimeter, probe the output voltages on the power supply when the TV is acting up and try to find one that is out of spec. My TV's power supply listed all the output voltages and the acceptable range for those voltages on the silkscreen near the bottom edge of the circuit board. Be careful when the TV is turned on though, there are some *shocking* voltages inside! The way I did it was to set up the multimeter probes with the TV turned off and then I turned the TV on with the remote, read the multimeter, then turned the TV off and moved the probe to the next voltage I wanted to read. This way you don't touch anything when power is applied.

[xerxesx20]

Great idea! Move probes on a dead board, NOT a live one. Might use that trick myself, i've got a telly power PCB problem myself. 8-D

[HeatherBell]

I have a Dell 42" Plasma TV that is around 5 years old. Last night it started with a wide black box at the bottom and then would disappear. Later that same black blob appeared in the upper left corner of the screen and now there is red lines that are distorting the picture. I turned it off and left it off all night and tried this morning and it is still messed up. I have read that it might be a Y board???? Is this expensive? I am questioning whether it is fixable and if so is it worth investing into?

Thanks!

[rrc1]

I have a dell w4200hd plasma tv i was watching it earlier today around 11am then turned it off and went about some errands when I returned home around 5:30 and my son turned it on all we saw were weird color lines, the cable worked we could hear the sound but see no picture just the weird color lines. Does this sound like something worth fixing or is it a dead end?

Help Please

[kmaguire1]

Ok i have w5001C HD but when i look up my Service Tag: 307XT71 it tells me: System Type: TV W4201

This BEAST is on the wall and what 200 pounds. So i stuffed my self up against the wall, got photos. I see that tag that says w5001c. but the other Service Tags are the same.

Why would dell tell me its a w4201 when its a 50" ? Just some Dell Scam?

So my problems. (well i had the issues before where no picture but sound, and picture would freeze. So Dell replace this about a month or two before the warranty ran out. that was about 2 years ago.)

My issues, i turn it on and it takes literally a minute or two before it boots up, before picture or inputs is on. The blue light comes on, but just takes forever for image to appear or sound.

Once picture is on, everything is fine. But once i turn off, turn back on it will take a minute or two to come back. Seems like its getting a little worse day by day.

So do you think going through your journal might be a good place to start?

Thanks

Kevin
kevin697788(AT) Yahoo.com

[Tswsupport]

We may be able to help you. We're Dell certified and have been working on them for years. This issues is finding parts, but once we get the parts we can help.

Manual:
http://www.tswsupport.com/Dell/DFoundations_2008_Desktop_CD5/
W4200/W4200/index.HTM

There KB: http://www.tswsupport.com/portal (Some docs are blocked)

[Beadboy444]

Mr12volt,
I have a w5001c that stopped working. I found a California company that repaires power supply boards. I was able to remove it, but they also want the YSUS board and the buffers. They stated it was the board to the left, so I was able to remove the lower panel to get at the screws but it it attached by a white microfilm(lack of a better word). Can I just pull that out and were are the buffers?

[pantalone]

Nice instructable. Your pictures are great (lighting and focus).

[tstsleeper]

Hello and thanks for the info. I have a w5001c that shower very similar symtoms. But after testing all the PS voltages the only one that was out of spec was the 5V line. It is reading 2.93V.

Trying to isolate the problem I disconnected all the cables, rechecked and I had 5.02V. So I plugged in each cable one at a time and checked the 5V. The only cables that changed the readings were CN8004, CN8007 and CN8008.
Here is a list of my readings:
8008 connected 3.20V.
8007 connected 3.04V.
8004 connected 3.03V.
8004, 8007, 8008 disconnected 5.02V.

Since all these cables go to different boards, I'm thinking the problem is on the PS board that only shows up when under load. I removed the PS and am trying to trace the 5V from each connector to see if they have any common components. This is a work in progress.

Although I use to do component level repair of circut boards back in the day. I haven't done so for over 20 years. Also all I have is a DVM to work with. If anyone has any ideas or suggestions please send them my way.

Thanks, Greg

[natedawg1013]

(removed by author or community request)

[jakdedert]

Okay...weighing in here over a year later: Tonight, found a W4200HD on the curb across the street from my apt. Glass is all good. Set turns on for a brief period -- blue OSD. Then the display blanks. Eventually some relays kick off, and a red LED on ps board lights. So far, I've got the back off for visual inspection, which reveals four very large electrolytics; two of which (1000 @ 250v) are alarmingly swollen. The tops are so bulged out they resemble balloons. The other two (330 @ 450v) are only slightly bulged...one almost not at all. All the other caps on the ps board pass visual inspection. My initial impulse is to replace these four, before even attempting voltage checks. Will post back w/pix and results. Keeping my fingers crossed.....

[mr12volt]

jakdedert, When electrolytics age, they just dry out and loose their capacitance, they don't usually dome. The doming often happens because of an overvoltage or reverse voltage condition. I would suspect the diode bridges. These are the four pin relatively large IC's (probably attached to a heatsink) that take the raw AC and turn it into a pulsating DC signal of ~175 volts peak-to-peak. If the diode bridge breaks it could allow negative voltage to go to the 250V caps, which I assume are used to smooth out that pulsating ~175V signal. A power-factor-correction controller chip (in a DIP package) takes the 175V pulsating DC and pumps it into the 450V caps (through a large inductor) making a stable ~387V DC bus. Look at the large resistor that goes from the negative side of the diode bridge to the negative side of the large 450V capacitors. That is a current sense resistor and may be damaged as well. If the diode bridge failed, it may have taken the MOSFET switches with it too, OR the MOSFETs may have failed first and taken out the diode bridge. If it doesn't work after replacing the diode bridges and the domed capacitors, look at the MOSFETs. Be aware that replacing components without knowing exactly what has failed is possibly dangerous and could be expensive. If you replace the diode bridge and caps then turn it on and the MOSFETs are still busted, you could end up destroying the components you just replaced. Just proceed with caution. If you want to be as careful as possible, replace the PFC controller IC, remove all MOSFETs and test them (with a multimeter), and test the diode bridges. By "test the mosfets" what I mean is make sure that the impedance from the gate to source and impedance from gate to drain is >1Megaohm and the drain to source connection is not shorted. Testing all of these would be a bit of a PITA because the pins are large and more difficult to desolder. Plus they are connected to heatsinks. If you handle the MOSFETs remember to keep yourself grounded so you don't zap them with static electricity. Best, mr12volt

[jakdedert]

Defective capacitors often fail in the manner I described. There are a lot of defective caps out there, due to the industrial espionage incident around ten years ago. Google 'Bad Capacitors' and among the nearly quarter of a million hits, read this: http://en.wikipedia.org/wiki/Capacitor_plague In any case, I replaced all the high-capacity/voltage caps on the main psb, and the set now works flawlessly. To be honest, I had planned to do more testing before slapping this board back in and firing it up; but given the difficulty in moving the set, I just went for it. So far, it's panned out. We'll see.....

[mr12volt]

Well that's embarrassing. Looks like I was 100% wrong on this one. Happy to hear that it was a simple fix. I guess I like to err on the safe side. How does one know before hand whether the capacitors failed because of a different component failure or because the caps were defective. If they are cheap parts, I suppose it's faster to just replace and pray. Just don't look at it when you flip the switch. Nobody like capacitor juice in the eyes :-)

[jakdedert]

You never know. If I'd been being responsible, I'd have confirmed all of the voltages as soon as I fired this thing up. Where it sits right now (with the back still off), it's not really accessible. I'm still crossing fingers that nothing else is wrong; but I've dealt with the aftermath of bad caps before. I have a Dell monitor which is famous for the problem. There's even an instructable about it. Dell--or their subcontractors--was a particularly frequent victim; and this plasma was built right at the peak of the problem time...mid-90s. FWIW, you were 100% correct, had the problem been 'good' caps gone bad; but these are only five or six years old. The problem is particularly insidious because not all of those caps will self-destruct, and the ones which do, will do so at widely varying times. There are a lot of factors involved...the main one being; how marginal is the rest of the design.

[bgegg]