NEC 50MP1

[Andy]

Can anyone suggest ways to self-repair my 4-yr old plasma - NEC want over $5K to replace it with a refurb - Screen lights up then goes black with the power light flashing red and green. My guess is the power supply - even if it's more than that nothing should cost me $5k to get this thing back up and working right??? It appears NEC are proprietary in their parts/repairs and render general electrical repair people unuseable. Thoughts anyone??? Much appreciated...

[Al_Dodge_Bundy]

Is the backlight working?
(If not, there could be a problem with the inverter-board.)

Do you have (maybe only just for a few seconds) any picture whenever you turn on the screen?
(It could be the power suply, or video board)

Grtz Mark

[Andy]

No picture comes up - just a 1/2 second or so screen light up and then it drops out completely... Thanks for your response...

[Al_Dodge_Bundy]

It could be a problem with the inverter board, can you check if the backlight is working (or only works shortly, whenever your turn on the monitor)?

(p.s. it offcourse could be a power supply problem also. Do you have a external, or internal power supply?)

[Dooney]

Andy, I used to work for NEC and was the European Technical Specialist for Plasma displays. If your product is a 50MP1 there is a strong possibility that 2 capacitors on the PDP module have failed. Best way to detect if these are gone is remove the rear cover, remove PCB's & shielding from the right hand side of the inside of the unit (from rear) and you should come across the scan PCB. This PCB will be extremely yellowed if the problem is the same. There are 2 electralytic smd capactors in the upper right corner of this pcb (next to heat sink) which fail. I will see if i kept the technical bulletins for this and inform you the actual comment names. Hope this helps.

[Stiff]

I have acquired 4 NEC 50 MP1 for free. They all pretty much have the same problem. They will display only half of the lower screen sometimes with bleeding and if I turn it off and on a few times it will display the entire screen but with the picture rolling. I also tried one that worked great for about 10 minutes then back to a rolling picture. Any clue on what on how to fix this?

[Dooney]

Hello Stiff,

Yes these are 100% fixable, each fault plasma will require 2 SMD capacitors removing and replacing 1 directly and 2 in parallel.

I can not remember the PCB label marks (ie C2300) but if you can remove the back cover and the shielding covering the Scan PCB (Right hand side from rear) and send me a photo i will point these caps out for you.

The problem is heat, the caps were designed to last 20,000 hours given the power load across them, the problem was that the internal temperature reduced this life to approx 5,000 hours and then these dry up and hey presto you have your half screen.

Once the capacitors are replaced the screen is restored to normal, the higher heat rating on the cap the better i think this was later modified to a cap that should reach 15,000 hours. The hotter climate you live in the shorter the life of these caps are......

Mike.

[Stiff]

Thanks Dooney for your help. Here are some pictures of the NEC 50MP1. I hope you can make sense of them. The below ip address is where they are at. If you cant get to them let me know.

Thanks!

http://69.175.94.15:1024/

[Dooney]

Hi Stiff,

Can you email me a close up of the board in picture (Cap0002.BMP) this PCB is the one causing you the problem and is known as the Scan board.

The area on this board which i need a close up of is the upper right hand corner as you look at the board, as this is where the 2 caps are located.

My email address is - [email protected]

Best regards
Mike.

[Stiff]

Thanks Mike,

I just added a few more pics and video plus an email.

Chris