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

[Securityman]

Faulty 61in NEC MP1
I have this screen and it will not switch on.
Yesterday it was fine, went out for a hr and when i come back and switched it on the green light come on, a little click like always but the screen is blank.
Tried changing the input, vol up or down to see if it was the input. But nothing on the screen.
I do have a have a spare screen with some boards on it to try if i know where to start looking.
I did see this refurbished board on the bay

NEC PX-61XM1A 61MP1 Buffer Plasma 942-200412 PKG61C1E2 | eBay

This must be a common part to go if the are refurbing them.

If not i was hoping to get it fixed if the cost was less than £300 total.
I might be a mile of with the cost to fix these things?

Any help would be great because i am stuck with a 17in CRT sitting under my 61in in the lounge at the moment. I feel like i have gone back to the 90s.lol

If not a new one might be in order, Led back light, plasma, Lcd or not..........

[tom66]

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

Well, pictures of the insides would help so we can tell you where to begin.

[Securityman]

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

Well, it,s still on the wall, only stopped yesterday. With it being 61in and not having a work shop to open it up in, i am getting some info first. I am more than willing to open it up, looks like i will have to clear the garage.

I was hoping someone would say "that it is this board or that board". Give me something to research before i remove it and open it all over the lounge floor with a toddler running about.lol


I think i have found a pic of the inside if that will help until i open mine up.
thanks
SM

Ps: Is it ok to lay it face down to remove the back?
I know it,s not great for transportation.

A little pic so you can see what i am stuck watching. Back to the 90s.

[tom66]

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

Yeah, so take a nice walk in the park and enjoy a few days without TV.

The most common faults when you have no picture, in order:
- Y buffer
- Y-sustain
- Z-sustain
- blown fuse on either sustain board
- Power supply
- PDP control board / X buffer (combined part, usually)
- Main board

It will require troubleshooting and probably a new board costing a lot of money, but almost certainly under the $5k price tag.

[Securityman]

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

Cheers Tom, thanks for taking the time to reply.
I will bump this up when i have opened it up unless anyone has any more info to add.

[cmj21973]

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

[QUOTE=Securityman;208336]

Ps: Is it ok to lay it face down to remove the back?
I know it,s not great for transportation.

QUOTE]

Yes. As long as you place something underneath to protect the screen. A couple thick bath towels or bed comforter.

[PlainBill]

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

<SNIP>.
thanks
SM

Ps: Is it ok to lay it face down to remove the back?
I know it,s not great for transportation.

A little pic so you can see what i am stuck watching. Back to the 90s.

The preferred method is to support the TV by placing the TV on some blocks to ensure no pressure is placed on the plasma panel itself. If you slide a mirror onto the bench below the TV, you can even see what is being displayed.

PlainBill

[Securityman]

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

So i am back, it's been to long watching a 17in CRT
I have cleared the garage and removed the back.
Just so you know i am a newbe when it come's to electronics.
I have built a couple of bread board circuits, but that's about it.
I can follow instructions ok, so should be fine with some help.
I have a fluke 77 series 2 meter and i am ok testing voltage and continuity.
I have a couple of soldering irons and a SMD station that i dont know how to use.

This is my first shot at some pic,s. I hope they are ok?
I will have to get some more light into the garage tomorrow if not.
The second pic is a board under the metal plate on the left.
There is another board on the right under the video board.
I can strip it down more if needed, but thought i would get these pic's out there in case i don't have to remove any more.

Any help would be great.
Cheers

[Securityman]

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

Have been having a look around the pcb boards and cannot see any popped caps.
Am i right i thinking that when it's switched on and the green LED come's on and stays on i am past a PSU board fault? If it was a PSU fault the LED would flash green and red?

Got the week off work so would love to have a good crack at this.
Anyone want to help?
Cheers

[Securityman]

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

These are pic's of a spare panel i have here.
It only come with the PCB boards that you can see in the pic's.
The one's around the edge have a, b, c, d, e, f, on them. Are they the buffer boards?

[tom66]

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

You have a spare panel? How?

Anyway... I have a Pioneer which did the same thing as yours. I fixed it - turned out to be some of the resistors on the PSU near the mains input. Can you post a closer pic of the area where power comes to the PSU?

[Securityman]

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

The spare panel.......a lucky buy on Ebay about 3 years ago for £30 with pick up only 10 miles away from me. It,s been in the garage all that time just in case. I was hoping it would of had more boards on it. But got to be worth £30 if i can use one thing out of it.

I will have to brush up on my photography, had to hang a lead light above my head to get more light.
I hope they are ok.

[tom66]

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

These three white devices are your "inrush" resistors.

They can fail open from either being worn out from many turn on/off cycles, or due to a shorted component further down the line (i.e. they act as fuses.) In one case on a Hitachi/LG PDP, it was old age (just replaced one of the three and it powered right up), but on the Pioneer, it was a shorted FET (on replacement, there was a "crack" and "pop" from the resistor... then it measured open circuit)

Flip the power board and measure the resistance of each. They will be labelled, but in general for a plasma of this size I'd expect <15 ohms each.

[selldoor]

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

Hi I dont know much at all about big tvs but happy to look at pics for possible problems. The ones of the set being fixed are not quite sharp enough for troubleshooting, really need to be able to read the board numbers. As you suggest good light is the key as flash washes out parts completely.
Anyway. pic 2 bottom left above socket F3 does it look like anything was on there. Above that check ic9401 is that just a mark or a hole burnt in!!
Same pic bottom right any ideas on what looks like a wire from pw across to the line of ceramic caps. Same corner the cap on its side above F4 is that soldered in firmly looks weird.Also samecorner in a bit from between socket SW &RS there is between the two ics a grey cylinder - looks a bit odd if you can check it. pic 4 middle top there is a small cap bent over - check it is not snapped off or loose.Also chec k the 4 big caps are not domed at the top. Pic 3 top right just check that blue cap is ok and not touching the metal plate. Also same corner there is an ic by the label AB that looks to have rusty!!? legs is it burnt?. Going blind now and its getting late for this.

[Securityman]

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

Selldoor i will have to check that lot in the morning because the computer is upstairs and i will need to print it off to check the panel in the garage.

Tom66
LOOKING GOOD.
I cannot believe that you may have diagnose the fault at the first crack.
Left to right, 1 to 3 in the pic you posted.
Number 1 and 2, GSW 10 ohms Micron 19T
1 = open
2 = 10 ohms
Number 3, 5A 2.2 ohms 01 04B, i think because i cannot see it great
3 = 2.2 ohms

So it looks like it's number one is the problem.
I tested all the other white box fuse's i could see on this board and they all read as spec.

Now where is the best place to get it in the UK and do i just it fit it and try to power up or is there any more to check before a replace and power up?

Just tried a Google search and cannot find anything. What is that part called?

[tom66]

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

Here's a replacement part. It is sometimes known as a sandstone cement resistor. (Despite being made of neither sandstone, nor cement.)

http://www.ebay.co.uk/itm/5W-Axial-C...#ht_1813wt_907

HOWEVER, before you replace it, check the resistance across the main 420-450V caps. (With power off.) It should measure greater than 1k ohms. (On your Fluke, you'll want to range to the nearest to 10kohm and set it to manual ranging (the autoranger will be confused by the caps), and wait for the caps to charge - you're looking for a stable measurement.) Anything lower indicates a potentially shorted component, which is the cause of the failure.

IF there is no short, it would be advisable to change both 10 ohm resistors and ideally the 2.2 ohm one too - the failure mode is by metal fatigue from rapid heating (they deal with peak currents when the TV is first turned on) so the others might not have long left.

[Securityman]

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

Just checked the main caps. Started at 0 ohms and climbed to about 8 ohms when i removed the probes. Should i hold them on to see where the reading stops?

So it could be a 50p component to get it up and running. Super, Great, Smashing.
I will order it up now.

Do you have a link to the 2.2 ohm one?
All i can find on the bay is this one from H/K and it's in a different format

http://www.ebay.co.uk/itm/10-Pcs-5W-...#ht_1685wt_952

[tom66]

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

Just checked the main caps. Started at 0 ohms and climbed to about 8 ohms when i removed the probes. Should i hold them on to see where the reading stops?l

Yes... this indicates something further down the line is shorted though. Double check you have your meter on the right range.

[selldoor]

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

Hi there are these ones

Your HK ebay link is for 2.2 K ohms 2.2KΩ
Maplins have them -http://www.maplin.co.uk/7-watt-wirewound-resistor-2179 As you say different format - perhaps solder extension to one side?

There are these ones
http://uk.rs-online.com/web/c/?searc...or+2R2&sra=oss

Dont know what postage is like for small orders looks like £10!!! perhaps you live near a trade counter.

And another http://uk.farnell.com/international-...w-5/dp/1436310

I have looked at CPC as they are just near me but they dont seem to have them or I could have got them for you.

What Wattage are yours

[Securityman]

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

Good morning, back to the garage after about 4 hrs sleep.

The Fluke i could only switch from k to M ohms. Not got the hang of auto ranging yet.

I tried it with a cheap meter i have here. UNI-T UT33B £10 job from the market.
This one:
http://www.ebay.co.uk/itm/Uni-T-UT33...ht_3890wt_1018

This one does not have auto range. It has 200, 2000, 20k, 200k, 20M, ohm range.
On the 200k ohm setting they all climb out of range.
On my pic number 4 the two caps closest to the ceramic Resistor's that i tested.
When on range 200k ohm setting they climb out of range, then i remove the probes, change to the 20M setting and they are at about 1.90 ohms and fall to about 0.27 ohms.

Remove probes, wait about about a min and retest, they climb from about 0.16 to 0.27 ohms. Then they climb slow from here, from 0.27 ohms to 0.28 ohms take's about 30 seconds.

The other two caps on the top left of my pic number 4.
200k settings out of range, 20M sit at about 0.16 ohms with a slow climb.

Does this sound about right?

I hope i am giving you the right info.

Cheers