NEC Plasmasync Repair. Replace Panel worth a try?

[jberrian]

Hi Everyone. I am new to the forum and can be considered a novice so apologies in advance if this query comes across as total n00bile.

The company I work for used several older NEC Plasmasync displays for various presentation purposes within the conference room, lobby and other public areas. Among the lot of them are two particular large plasma displays sitting in storage that were taken down last year for maintenance issues several months before I was hired as the sysAdmin. The units are older and out-of-warranty.

The displays are:

Display #1

NEC model 42Mp1: Was disassembled for what appears to have been bad boards/caps or a faulty power supply. I don't have much detail but according to the notes, the actual pdp screen functions okay (picture displays) but the unit intermittenly powers down after a few minutes or goes into a blank screen. The faulty board(s) or power supply were neither identified or replaced. Unit remains disassembled w/possibly some missing boards.

Result: Good panel/Bad or missing internals.


Display #2

NEC model 42mp2: Was taken down with a damaged panel. According to the notes, the unit powers on but shows physical damage to the plasma display screen. Likely a cracked screen. Internal components function properly.

Result: Bad Panel/Good internals.


If you didn't already venture a guess...I am curious if the mp2 internals are compatible with mp1 pdp?

In short, do they *likely* both use the same model pdp glass?

The panels themselves *appear* virtually identical to each other especially in design, vital specs, resolution and within the internal layout and build of each unit. Even the mounts, screws, ribbons etc. *appear* exactly the same.

There are obviously some kind of feature differences between the two displays though I am unsure exactly how those differences might translate into hugely significant changes within the actual hardware particularly with the screens.

Research on google shows that the mp2, the latest of the two units, has a slightly better contrast ratio and few other proprietary features that perhaps (speculation ------>) may be engineered into the boards only and not necessarily using a totally new generation of panel?

I've been given the opportunity to take the displays and various other parts home with me though I wouldn't want to attempt the reassembling of the unit if its indeed futile. Also, I wouldn't dare mix & match boards or power supplies from different generation units. I would however give this repair a shot if they both happen to use the same *exact* glass.

Worth the try?

[jetadm123]

Re: NEC Plasmasync Repair. Replace Panel worth a try?

Speaking from the LCD computer monitor side of things, you can have two same exact model monitors, yet their power supplies can be made by two different companies. The same situation could apply to your NEC displays. And the only real way to find out the internal differences is to pull off their rear covers and start comparing modules. Obviously, if the modules are different part numbers or look different from one another, then yes, you might wasting your time trying to pull parts from one to fix the other. On the other hand, if they share the same model power supply and the power supply is the only problem, then Christmas may come early this year!

[PlainBill]

Re: NEC Plasmasync Repair. Replace Panel worth a try?

Properly speaking, a plasma panel consists of a number of cards as well as the panel itself. There are several things to check.

What are the model numbers of the plasma panel itself? This is usually on a white label on the back of the plasma panel.

Another white label on the back of the panel lists the proper voltages for operation of the panel. Do these voltages match?

The Y-sustain is on the left as you look at the back of the TV. The Z Sustain is on the right. Do both panels have identical sustains?

PlainBill

[jberrian]

Re: NEC Plasmasync Repair. Replace Panel worth a try?

Properly speaking, a plasma panel consists of a number of cards as well as the panel itself. There are several things to check.

What are the model numbers of the plasma panel itself? This is usually on a white label on the back of the plasma panel.

Another white label on the back of the panel lists the proper voltages for operation of the panel. Do these voltages match?

The Y-sustain is on the left as you look at the back of the TV. The Z Sustain is on the right. Do both panels have identical sustains?

PlainBill

It appears as if I have to take apart the mp2 to locate the white label identifier and compare it to the mp1. My instinct tells me that the glass is the same for both units and that the boards were the major upgrade between each generation. Would that be a common-practice for plasma manufacturers? Would it be far out to assume that manufacturers would upgrade a board or two, do a firmware update, call it a new generation while using the same glass?

As mentioned in the OP, one major difference between both panels seem to be contrast ratio where the mp2 shows a higher ratio than the mp1. Now, to achieve that higher contrast ratio, would a whole new generation of panel be required? Or could a higher contrast ratio be achieved or improved upon through the engineering of upgraded boards and software/firmware?

To answer your questions about the Y/Z boards...they all appear identical between both units. In fact, I am having some trouble spotting any significant or obvious differences between both units' internals. I will be comparing the part #'s of each component as per jetadm123's advice in the post above yours to identify similarities and differences.

If the panel's match each other (according to the white label) my goal is to transfer the working Mp2 internals on the mp1 panel. If I can swing it, I'd have no immediate plans to mix-and-match identical boards even if they are a perfect match. My guess is that the components likely do not match in age even if they are the same.

I've got the philips head out and about to go to town on these. Any last minute words of advice for a novice?

I'll post some pics of my find. Stay tuned and thanks in advance for any replies.

[PlainBill]

Re: NEC Plasmasync Repair. Replace Panel worth a try?

It appears as if I have to take apart the mp2 to locate the white label identifier and compare it to the mp1. My instinct tells me that the glass is the same for both units and that the boards were the major upgrade between each generation. Would that be a common-practice for plasma manufacturers? Would it be far out to assume that manufacturers would upgrade a board or two, do a firmware update, call it a new generation while using the same glass?

As mentioned in the OP, one major difference between both panels seem to be contrast ratio where the mp2 shows a higher ratio than the mp1. Now, to achieve that higher contrast ratio, would a whole new generation of panel be required? Or could a higher contrast ratio be achieved or improved upon through the engineering of upgraded boards and software/firmware?

To answer your questions about the Y/Z boards...they all appear identical between both units. In fact, I am having some trouble spotting any significant or obvious differences between both units' internals. I will be comparing the part #'s of each component as per jetadm123's advice in the post above yours to identify similarities and differences.

If the panel's match each other (according to the white label) my goal is to transfer the working Mp2 internals on the mp1 panel. If I can swing it, I'd have no immediate plans to mix-and-match identical boards even if they are a perfect match. My guess is that the components likely do not match in age even if they are the same.

I've got the philips head out and about to go to town on these. Any last minute words of advice for a novice?

I'll post some pics of my find. Stay tuned and thanks in advance for any replies.

If the Y and Z boards match the panels are for most purposes identical. There are several adjustments necessary on the Y-sustain that match it to the individual panel. The power supply voltage specific to the individual panel may be different (these are on a label on the back of the panel).

A full swap of boards from the 42MP2 to the 42MP1 is probably the best approach. It would be nice to keep the Y-sustain and Y buffers from the MP1 because they have critical settings that require an oscilloscope to get right. Unfortunately, they are a common failure item, and may cause what appears to be power supply problems.

The final bit of advice: Be careful. There are poinst that carry 200 volts at high current. That bites.

PlainBill