Faulty 61in NEC MP1 plasma tv, stuck with a 17in CRT in the lounge

[selldoor]

Re: Faulty 61in NEC MP1 plasma tv, stuck with a 17in CRT in the lounge

I think id go for Tom's if you click on product info it tells you a bit more and on the right hand side it has manufacturers part no SQM710RJ and if you google that
the data sheet is here
http://www.datasheetdir.com/SQMW7R10J+download
Where I think it is saying it has 10 times the power for 5 seconds which I interpret as surge

[Securityman]

Re: Faulty 61in NEC MP1 plasma tv, stuck with a 17in CRT in the lounge

Thank you both for your help.
Just seen Rs is only open Mon to Fri. I will try the 7watt one from Maplins because i have got to go there today anyway. I will have to bend one of the legs over to fit it.
Would prefer to fit a branded one from Rs as i cannot see a manufacturers name on the Maplins one and i should think cheap for from far a field.
On the Maplins overview they say
"The resistors are low noise, very stable and have an overload capability of ten times the rated power for 5 seconds".

http://www.maplin.co.uk/7-watt-wirewound-resistor-2179

On another note, i need a new soldering iron, i went to use my cheap £20 temp controled soldering iron from Maplins to fit the Resistor on Thursday and the element has gone, got the SMD station down that has not been used for about 3 years, will not power up. I had to use an old Antex iron that i got from a boot sale about 10 years ago for 50p, never tested, just stuck the bottom of the tool box. That got me out of trouble.lol. To think that old 50p iron done the job.

I see this one on Maplins for £60
http://www.maplin.co.uk/60w-professi...tection-511927

Found it on Ebay for £49
http://www.ebay.co.uk/itm/60W-Profes...#ht_945wt_1185



Or this one for £30
http://www.ebay.co.uk/itm/2307804874...ht_2024wt_1185


I would like one that i can get new irons and bits for if need be and hopefully it will outlast the other crap that i have brought before.


What do you think guys or any recommendations for a reliable lowish cost iron?
Maybe i should stay away from the all singing and dancing irons because it will only get used about 5 times a year.
What i really want is reliability, a iron that i can get it of the self after not being used for say 6 months and do the little jobs i do.

[selldoor]

Re: Faulty 61in NEC MP1 plasma tv, stuck with a 17in CRT in the lounge

I looked at the maplins resistors - in fact I think I mentioned them earlier.
They have the same "surge" statement as the RS ones the downside is that
the lead may not be long enough to bend over and you will have to join it and I didnt know how much height you have to play with. Some I have seen have a groove in the side to accomodate vertical placement but cant tell if these have.
If they dont I would slide on some sort of insulation when fitting.

Soldering irons - no good asking me I have 2 or 3 25watt ones with different tips and a 40 watt chisel tip one is a weller others are just whatever was cheap at maplins or cpc at the time. I like the look of the Atten soldering station with a couple of extra tips but dont know if it is any good. I would not get enough use out of it and probably could not justify the expense unless all my other irons gave up at the same time.

[Securityman]

Re: Faulty 61in NEC MP1 plasma tv, stuck with a 17in CRT in the lounge

Ok, so i fitted the 7w resistor about 6 pm last night. Powered up fine, power cycled it about every hr and run it for 10min at the time. All fine up to midnight when i called it a night.
Got up at 8am, went to the garage not holding much hope, but she powered up fine.
Tested it again at 11am and its still powering up ok.

I think i will give it a couple of days testing before getting it back on the wall. Not easy getting it on and off the wall.

So why do you think its not liking the start up current now after about 5 years of trouble free use?
If it was a part further down the line, would of popped the resistor straight away?

I guess its hard to say with out some proper testing equipment.
But any comments are welcome.

Thanks for the comments Selldoor, i used the cut off from one leg, i soldered that to the short leg then use heat shrink for insulation. Height was not a problem.

Once again thank you all for you help.
If you ever need any help with alarms give me a shout. Hopefully i can repay the help at some point.

[tom66]

Re: Faulty 61in NEC MP1 plasma tv, stuck with a 17in CRT in the lounge

The replaced resistor may not have been as good as the original.

[Securityman]

Re: Faulty 61in NEC MP1 plasma tv, stuck with a 17in CRT in the lounge

Bad news, the same thing has just happened. Got 17 days out of it this time.
I have a 10w resistor , do you think i should try that?

[tom66]

Re: Faulty 61in NEC MP1 plasma tv, stuck with a 17in CRT in the lounge

Bad news, the same thing has just happened. Got 17 days out of it this time.
I have a 10w resistor , do you think i should try that?

It would probably work. You could also bypass the resistors if your household breaker is good enough. My 32A type B does not trip when I do this with a 50" (with more bulk capacitance than your 61") however it does make the lights visibly flicker. One way you could test this it by briefly interrupting the power to the TV as it will then suddenly draw a lot of current when the power comes on quickly...

[Securityman]

Re: Faulty 61in NEC MP1 plasma tv, stuck with a 17in CRT in the lounge

If i "bypass the resistor" will that not just pop the next 10 ohm resistor?
How the missing 10 ohms?
How about a thermal fuse, would that be any good to replace it with?

[tom66]

Re: Faulty 61in NEC MP1 plasma tv, stuck with a 17in CRT in the lounge

If i "bypass the resistor" will that not just pop the next 10 ohm resistor?

How the missing 10 ohms?

Both resistors would need bypassing.

How about a thermal fuse, would that be any good to replace it with?

No, thermal fuses would probably fail quicker than ordinary resistors.

[Securityman]

Re: Faulty 61in NEC MP1 plasma tv, stuck with a 17in CRT in the lounge

How about the next one? The 2.2 ohm one?
Would you say bypass all three?
Just with a wire link?
Will the panel run ok without the three resistors? or would the problem move up the board over time?

[tom66]

Re: Faulty 61in NEC MP1 plasma tv, stuck with a 17in CRT in the lounge

How about the next one? The 2.2 ohm one?
Would you say bypass all three?
Just with a wire link?
Will the panel run ok without the three resistors? or would the problem move up the board over time?

2.2 ohm should stay - probably for another supply. I would bypass only the first two.

The PSU should be fine with just wire links but do check that it won't trip any household breakers. There is a reason those resistors are there.

Maybe as caps age they draw more current? I don't understand why this would happen, normally they would draw *less* current if near failure.

[Securityman]

Re: Faulty 61in NEC MP1 plasma tv, stuck with a 17in CRT in the lounge

The 2nd 5w 10ohm resistors had gone, it was a new one. Changed it for a 10w one i had here.
1:30min from off wall to back on wall watching tv. I think i will see how i go with this fix.
Once again, thank you Tom and selldoor for your help.

[Securityman]

Re: Faulty 61in NEC MP1 plasma tv, stuck with a 17in CRT in the lounge

I thought i would update this thread.
I/we could not put up with it any more, it has been off and on the wall about 5 or 6 times in total. So i bit the bullet and ordered the only PSU board i could find which was in the US, got hit with customs charge as well.

I hope it gives me a bit more use. Before it had a little buzz which has gone with this new board, so that must of had something to do with it.

Thank you all for your help.

[hkposition]

Re: Faulty 61in NEC MP1 plasma tv, stuck with a 17in CRT in the lounge

I'm having a similar problem with my NEC. Did the new PSU board solve your problem? Thanks. Tom

[Yoly66]

Re: Faulty 61in NEC MP1 plasma tv, stuck with a 17in CRT in the lounge

Hi, I also have the same problem with this same model and would really like to know if the new board fixed it.

Thank you

Yoly

[hkposition]

Re: Faulty 61in NEC MP1 plasma tv, stuck with a 17in CRT in the lounge

For someone who may be passing through this thread who may want to know what was sucessful for me, I am posting this update. I had asked the OP what his final resolution was but he hasn't responded.

I have a Runco PL-61CX which appears to be exactly the same as an NEC PX-61XM1A. The symptom of the orginal problem is that the monitor would not power on. When it was plugged in and the main power button pressed in, the front LED would be solid red as expected. Then when turning it on, the LED would go solid green, 2 clicks would be heard, again as expected, and then 5 seconds later another click would be heard and that's all she wrote. The LED would stay sold green but no picture. I traced the problem to a bad R3 which is the 2.2 ohm resistor on the power board. My power board is a 3S110022. R3 was open. I replaced it with the exact same size - 2.2 ohm, 5 watt, cement radial - and now the screen worked as expected. Power plug in + main power on = solid red LED. Turn it on = solid green LED + picture.

Unfortunately, after about 20 minutes of operation, it failed again. This time it was R2, the 10 ohm resistor beside R3. I replaced all 3 resistors, R1, R2 and R3 which are all 5 watt radial cement with R1 and R2 being 10 ohms each and R3 being 2.2 ohms. Same result. Worked for 20 minutes and failed. This time R1 was open.

I spent a lot of time troubleshooting and concluded that everything looks good and it was some marginal component or set of components that, after 11 years of use, were drawing more power and exceeding the 5 watt rating of the resistors.

I then studied the land pattern on the power board and found that the 3 resistors were wired in series, meaning 22.2 ohms. Hoping that I didn't fry the entire set, I soldered in a 12 gauge shorting wire across the 3 resistors. I was really hoping that it was just a marginal component problem. Well, the set came on and stayed on....for 8 hours. Then the next day it worked again. After 14 days, all looked good. It worked everyday.

I decided that to put it all back together with no resistor in place was not a great idea. These inrush resistors act as fuses and I should put some protection in place in case something really does go wrong. I need that protection. Since all 3 resistors were wired in series, I replaced all 3 with a 22 ohm 20 watt resistor. I know I could have tried a 10 watt unit but I was getting a little tired of soldering resistors into this thing and the land pattern was not happy either. 20 watts is 4 times the rating of what was in there but at least it was some protection...better than a 12 gauge piece of copper.

The bottom line is that monitor is running perfectly now for several weeks and I'm completely back online. Score!!!

FWIW, my monitor is on 2 stands on a shelf in an alcove in the wall. It is NOT mounted to the wall. The first 2 times I worked on it, I got a helper and set it face down on some pillows to work on it. Not an easy maneuver for 125 pounds. What I found out is that, in my case, it was way easier to simply turn the monitor 180 degrees on it's shelf, insert a non-skid pad under the length of it, remove the 2 stands, lean it against the wall upright and take the back off. Much easier to do...one man job...easier to work on.

Also FWIW, my reasoning that some components may have become marginal was based on another problem I had with this monitor. A few years ago, half the screen went black while the other half worked fine. It turns out that NEC had spec'd some capacitors that were very close to marginally OK for the circuit design and that too much fluctuation in the tolerance of the other components around the capacitor and it would get fried. I replaced that capacitor whith a more appropriate value and all was good again. That suggested to me that the rating of 5 watts on the inrush resistors may also be near the limit. Maybe NEC didn't expect anybody to be using this monitor for 10+ years and that component fluctuations over longer periods of time were not considered too much.

Anyway, if your asking why I have gone to all this trouble for a 10+ year old plasma monitor....simple. First I am an electrical engineer and don't like to think there is any circuit that's going get the better of me. Second, the picture on this plasma unit is still beautiful. Even after 10+ years, the colours are vivid, the brightness and contrast are great and the size is perfect for my video room. I'm not a fan of LED monitors in this application and I don't know if any plasmas available today would best what I have other than the fact this NEC is 720p max.

Long-winded yes....bit I'm sticking to my story. Hope it helps someone. Tom

[Yoly66]

Re: Faulty 61in NEC MP1 plasma tv, stuck with a 17in CRT in the lounge

Tom,
Thank you, My husband and I have been struggling with this problem on this exact tv for about 6 months now. It has been sitting in our hallway, leaning up against the wall collecting dust. I just did not want to get rid of it. I am so happy to have a plan of action... Thank you very much!

Yolanda

[Securityman]

Re: Faulty 61in NEC MP1 plasma tv, stuck with a 17in CRT in the lounge

Hi

Sorry for not updating here.

As of today's date i am still using my NEC, it has been fine with the PSU board i got from the USA.

hkposition, looks like you have got to the bottom of the problem. Thank you for the detailed info. I am sure it will help me and others searching the net.
Looks like there's still life in these panels for the time being.

I am sure we will talk again...................

Once again thanks to Tom66 and everybody that helped me.