Changing input power supply for a plasma (TC-P65VT60)

[ianmck]

Good evening all,

I've imported my favourite TV of all time back to Canada from my time in Australia, so naturally am faced with a 240V input voltage requirement. Currently this is served by an external transformer and the TV seems to work quite happily off this. Unfortunately, as with most transformers, there is always a noticeable buzz when the TV is in use.

Looking at the forums so far, it looks like lots of the internal circuitry in plasmas is designed to get the voltage and current to the right levels for each specific part. This suggests that one or two of the power boards up front are the ones responsible for converting the mains voltage into something that can be used by the TV. In turn, I would then believe that swapping out the (presumably) Australian power board for an American power board would be sufficient to allow the TV to now take a 120V input natively and more gracefully than with the bulky transformer.

As noted previously, the TV is an amazing piece of kit so I'd hate to either order some useless replacement parts or even worse damage it irreparably. Does anyone have experience successfully doing the above?

Many thanks.

[tw2005]

Re: Changing input power supply for a plasma (TC-P65VT60)

may be worth getting the part numbers off that Aussie board and also photos just in case it's the same board as US. Being switch mode it may run 110-240vac but I'm not saying plug it in and try it either.

[budm]

Re: Changing input power supply for a plasma (TC-P65VT60)

There are two power boards: Main and sub as shown at shopjimmy:
http://www.shopjimmy.com/catalogsear.../?q=TC-P65VT60

Pictures provided by SHOPJIMMY.

[fzabkar]

Re: Changing input power supply for a plasma (TC-P65VT60)

Panasonic's spec sheet for that model, as sold in the US, specifies an input voltage of 120VAC:

[tw2005]

Re: Changing input power supply for a plasma (TC-P65VT60)

I've used this guy plenty of times if you need a new P board, very cheap.

http://www.paylesscomponents.com/pan...y-mpf6915.html

[ianmck]

Re: Changing input power supply for a plasma (TC-P65VT60)

Thanks for the part sources!

This is actually the Australian version of the TV, so has a tag specifying only a 240V input voltage. The odd thing is that the part numbers are the same between the US supplies (Jimmy's / Payless) and the Australian model.

This means it might actually be a switching power supply that they just refrained from labelling as such, similar to how the PS4 works.

Looking at the powerboard diagrams is there any way to tell? I think the small fuse near the bottom right of the MPF6916 board being a 250V 10A fuse is a bit of a give away that it can handle something other than 120V.

[tw2005]

Re: Changing input power supply for a plasma (TC-P65VT60)

Thanks for the part sources!

This is actually the Australian version of the TV, so has a tag specifying only a 240V input voltage. The odd thing is that the part numbers are the same between the US supplies (Jimmy's / Payless) and the Australian model.

This means it might actually be a switching power supply that they just refrained from labelling as such, similar to how the PS4 works.

Looking at the powerboard diagrams is there any way to tell? I think the small fuse near the bottom right of the MPF6916 board being a 250V 10A fuse is a bit of a give away that it can handle something other than 120V.

yes TH-P65VT60A I expect is it's real model number.
I would expect it to say that and it may very well be 240Vac only for the TV , but I would like to see an image of the boards showing the part numbers on it.

P, P sub, & A boards at least. ,A board could have a TNPHxxxx + suffix as a number

Straight up you're quoting the sub P board number which i don't expect will need changing as it runs from the main P board.

It's the primary P board we need to see and check.

The other thing is if the primary p board does have to be changed then next step will be to confirm what connections are on it and pinouts.

i have a suspicion panasonic in it's last models may have started using A boards which can be used across different continents.

In the past though I think AU boards were fairly unique to us , may have been used in Thailand but not 100% sure.

[fzabkar]

Re: Changing input power supply for a plasma (TC-P65VT60)

The shopjimmy PCBs that budm uploaded have four 450V capacitors, two for each of the Vsus_L and Vsus_R supplies. Would that be one capacitor as the primary mains filter and the second for the APFC? If so, then ISTM that these US (?) boards are designed for 120V/240V operation.

[ianmck]

Re: Changing input power supply for a plasma (TC-P65VT60)

Interesting, I had thought it was the Sub-P board that was where the mains voltage connected to first.

There does seem to be a lot of 240V specified components on the US parts which suggests that I may be in luck. You're absolutely right about the part numbers though; I'll bite the bullet and figure out how to take the back off to get some proper photos of what's actually installed. Hopefully it's a fairly simple enterprise of just removing every screw on the back!

Appreciate the comments and assistance thus far. It's a bit nerve wracking to be toying with what is a practically irreplaceable set.

[fzabkar]

Re: Changing input power supply for a plasma (TC-P65VT60)

The MPF6916 board appears to consist of an EMI filter, a "Main" relay for on/off switching, a "Rush" relay for bypassing the inrush current limiting resistor (R005), and 4 rectifier diodes. I would think that this board should handle 240VAC, but I would check the capacitor ratings just to be sure. C012 appears to be a 450V part.

[budm]

Re: Changing input power supply for a plasma (TC-P65VT60)

The main power supply board does have the PFC so the boosted Voltage on the main filer caps will be around 400VDC.
Look at the current rating of the main AC fuse of the 230V version you have, it should be 1/2 of the rating as used in the US board.

The MOV Z001 (across L and N) on the sub power board value cannot be the same either for the 230V and the 120V version.
There are also two more MOVs connected to the bridge rectifiers, check the values too.

[ianmck]

Re: Changing input power supply for a plasma (TC-P65VT60)

Alright... I've got some images now that show the boards as installed in a bit more detail. I've also gained a new appreciation for just how sharp unfinished sheet metal is--ouch.

The Sub-P board is a MPF6916 instead of a MPF6916A as shown in the Jimmy's part shots. It looks like the fuses are rated the same on both boards. As far as I can tell, there are two major differences:

1. The "coil" on L004 is missing in my board while it's on Jimmy's
2. There is a second "black box" at the far left of the board on my board, but not on Jimmy's

My board also has a different secondary identifier (CA3201721A vs. CA2403356A) but I'm assuming this may just be a serial or manufacturing tracker.

The main P boards are the same model number (MPF6915), but again the serials are different (CA3200746B vs. CA2600623A). These two boards appear very similar, such that I couldn't pick out any immediate differences. Some of the labels on the surface of the large black coil elements on the left of the board are different, but I'm assuming the leading portions that are the same are model numbers while the later numbers are manufacturing times or locations.

Assuming this is true, it looks like swapping the MPF6916 board for a MPF6916A board may be successful, as there are only three connections between it and the P board. Or, does the missing coil and extra "black box" not matter and this is actually a switching power supply natively?

[fzabkar]

Re: Changing input power supply for a plasma (TC-P65VT60)

That "black box" appears to be a 450V capacitor. Can you tell if the two capacitors are connected in parallel?

The L004 coil is part of the EMI filter. I often see these parts linked out to save a few pennies.

I can't see any reason why your TV couldn't run directly from 120VAC. I'd hate to be wrong, though.

[tw2005]

Re: Changing input power supply for a plasma (TC-P65VT60)

Does appear I've got this wrong then. Sub does appear to be the mains input

[budm]

Re: Changing input power supply for a plasma (TC-P65VT60)

Look at those resistors on the bottom side of the main power supply board, there are rectifiers and resistors which are fed by the LINE and NEUTRAL so those resistors may not be the same values as used in the 230V version.
There are so many details that you must pay attentions to.

[tw2005]

Re: Changing input power supply for a plasma (TC-P65VT60)

That "black box" appears to be a 450V capacitor. Can you tell if the two capacitors are connected in parallel?

The L004 coil is part of the EMI filter. I often see these parts linked out to save a few pennies.

I can't see any reason why your TV couldn't run directly from 120VAC. I'd hate to be wrong, though.

I'm thinking same. main P board is the same part number. Sub board topside has different filtering but I'd expect it to work so If this was my TV I'd get a sub board

$10, a gift

http://www.paylesscomponents.com/cat...ult/?q=mpf6916

[ianmck]

Re: Changing input power supply for a plasma (TC-P65VT60)

As a wise man once said, he who hesitates has a reckless disregard for the health of his television set. On a hunch, supported by fzabkar's assumption, I decided to bite the bullet and just plug it into 120V mains power. Surely the worst that could happen would be that a fuse on the sub-P board blows (doing its job as a power entry point to protect the P board), right?

As it turns out, the TV seems perfectly happy on 120V power despite the one fewer coil and extra capacitor. Success!

I have no technical idea why they wouldn't label the unit as being able to handle switching power, other than to discourage circumvention of regional restrictions.

For all those Google bots out there, the TC-P65VT60A can handle 120V power natively without need for a transformer or power board swap out. Makes me feel a little bit silly for dealing with that transformer buzz for the better part of a year!

Thanks for all your help!

[tw2005]

Re: Changing input power supply for a plasma (TC-P65VT60)

As a wise man once said, he who hesitates has a reckless disregard for the health of his television set. On a hunch, supported by fzabkar's assumption, I decided to bite the bullet and just plug it into 120V mains power. Surely the worst that could happen would be that a fuse on the sub-P board blows (doing its job as a power entry point to protect the P board), right?

As it turns out, the TV seems perfectly happy on 120V power despite the one fewer coil and extra capacitor. Success!

I have no technical idea why they wouldn't label the unit as being able to handle switching power, other than to discourage circumvention of regional restrictions.

For all those Google bots out there, the TC-P65VT60A can handle 120V power natively without need for a transformer or power board swap out. Makes me feel a little bit silly for dealing with that transformer buzz for the better part of a year!

Thanks for all your help!

I'd still get the correct sub board. I don't think they'd change the cct for the hell of it for the 120V market and it does run at 60Hz as opposed to our 50Hz.

I have a US board from a g20 and I plugged it in on 240 for curiosity some time ago now just to see what happened and it worked.

[budm]

Re: Changing input power supply for a plasma (TC-P65VT60)

I would have thought they will put 120/230V sticker on the back of the TV and in the user manual. I would definitely keep an eye on it.
The sub board really does not have much of the active components except the bridge rectifiers and the MOVs (higher Voltage than it should be for 120V so the protection for the surge will not be as it should, it should be 150V MOV for 120VAC), the relays are driven by the main board, the x/y CAPS are rated at 250/275VAC so I do no expect the sub board to be the problem.

[ianmck]

Re: Changing input power supply for a plasma (TC-P65VT60)

Cheers folks, I will likely go ahead and order the correct sub-P board to patch in later. Will also have to keep the old 240V board around just in case I need to move regions again! The problem will be finding the motivation to install it, I think...