Checking Vs and Va voltage on my 50 inch plasma TV and simple troubleshooting guide.

Do this at your own risk since the voltages have to be checked with the TV powered on.
The power supply board has high voltages and can KILL you if you touch the wrong part.
Wear rubber gloves for protection when handling the power board.
A lot of Plasma TV problems relate to the SMPS power board and the Y sustain and Y upper and lower buffer boards. Aside from the obvious bulging or blown capacitors and burnt resistors, a good first start is to check the Vs and Va voltages on the power board. If the voltages are off, other components might not work properly. You can also check the voltages off the various connectors to see if the attached boards are getting the right voltage. After your repairs, you might have to adjust the Vs and Va voltages using the label with the proper voltages at the back of your plasma TV.
Click here to see part 1 on replacing the Y sustain board on this 50 inch plasma set:
• Replacing the Y Sustai...
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[@myveryownpersonalyou]

Very informative, thanks for sharing. My plasma tv has no picture. Testing the Va & Vs they were way below normal. The Led on the logic board was also flashing slowly. On for 5 seconds, off for 2. Disconnecting my Y board and the Va & Vs values returned to normal and the Led on the logic controller flashes once a second. I believe from watching the video it is the Y main or buffer. Still wanting to spend as little as possible... I'm considering taking each capacitor off circuit and testing as there is no components that look dead. If this doesn't work...... I'll be replacing both anyway as recommended to.

[@tendiful]

Va is an short for the Address supply Voltage. Vs is short for Sustain supply Voltage. These are the primary supplies to "run" the plasma panel. You could say V-address and V-sustain.

[@wtam69]

Thanks for giving a piece of information that is not widely available.

[@alinoltean4167]

@@wtam69 Hi i have one more power on the power supply board, it's called Vg and on the panel's back says it should be 95v. What is it's purpose?

[@regisnavarro113]

Tks for sharing what you know. Don´t pay attention to bad comments. Your tutorial helped me a lot, and I finally solved the tv problem. Again, thank you.

[@wtam69]

You are very kind Sir, thanks.

[@joshkelnhofer5454]

Regis Navarro Agree. I can't stand rude KZbin jerks. Great work and thank you.

[@Home_made_ch]

What is bad on power board if both voltages are not good?

[@wtam69]

You can try turning down the Vscan voltage (usually counterclockwise) and see if that helps you. The high voltages on the power supply board can kill you so find someone with electrical knowledge to do the job for you.

[@CSSIandAssociate]

Thanks for the updated version of your tutorial I was able follow along well. Made lots of notes.

[@wtam69]

William Ward Good luck.

[@Measuray]

Wtam69, it's okay to touch the heatsink on top for warmness. Usually, it's how you can tell which board is working by the heatsink being warm. If heatsink is cold after 1 or 2 hours, then board is probably bad.

[@wtam69]

A temporary fix would be to put a fan on it. I have 3 computer fans hanging in the back of the tv to keep it cool Too high a voltage will cause hot spot and sparkles too.

[@wtam69]

These modern televisions are not that reliable and costly to repair. I hope the little I know is of some use. Thanks for commenting.

[@wtam69]

Good luck and be careful.

[@ryann2k1]

Thanks. can you explain what is VA, VS, VE etc...what are these voltages are used for?

[@jean-marcdray8633]

Hi, my plasma Samsung TV doesn't light on and make loudly noise when I plug it. Measured VS and VA voltages are too high : VS=447V, VA=125V. On the board stick, it is written : VS 203V, VA 55V. What do you think ? Is the power board dead ? Thank you.

[@wtam69]

Voltage doesn't sound right. Have it checked or replaced by a technician.

[@pauloc.7924]

VS=447V, VA=125V? Sounds like double (at least) to me.. That's becouse you checked the voltages with a multimeter turned for AC (alternate current) and not DC (continuous)...

[@dansmith3424]

video was very helpful. I took some notes down,, im going to be troubleshooting my lg soon

[@ReganMarcelis]

Great video, what if I mess up all the Phillips head plastic volt adjusters on the power supply and Zeus as well as ysus? Which info do I need for re setting the ysus and Zeus boards as have a PL4260N HP, thanks. Pink lines in it, logic board or possible voltage I messed up? Thanks!!!

[@joshkelnhofer5454]

How about constantly flickering picture? Looks like when you have a loose cable making intermittent connection. All inputs, tuner, and menus do it. As if a connection to the actual panel. From research seems to be main board. Any thoughts? 2009 Samsung Plasma

[@JC-jy9lm]

What an excellent video. The picture wasn't to bad at all friend. Thank you for taking the time to make this video. There was only one thing I would ask. You say to be careful when testing the power supply because of electric shcok . I am wondering which parts imparticular we have to be careful not to touch to avoid getting a shock ? The capisitors and fuses I assume ?? Thanks again for the video :-)

[@wtam69]

Unfortunately not all power supplies are labelled with warning stickers so I'll be careful all round. On this board, you see the areas of danger with the lightning symbols. The areas with the labels are obviously dangerous. You have to know the AC side or the hot side and the dc side. Some power supplies actually have that etched on the board hot and cold. If you don't have that then you wouldn't want to guess. Anywhere near the AC in is not going to be good. DC can kill you too so I don't want to or know enough to tell you which specific part is safe or not.

[@JC-jy9lm]

Ok thanks again

[@element74]

awesome ur using the smpa board that I have. Also you said disconnect all the connector on the right, except leave the y-sustain board connected. Can you please specificy which connectors we can safely have disconnected? For example, is it ok to leave the F-buffer board disconnected? The other connects besides the Y-sustain board are the X-sustain, F-buffer, control board, AV board, AC plug.

[@marcucristian80]

Hello. What can I do if i only have 3.2V instead of 5.3V on standby? I have changed the regulators, transistors, diods, capacitors and still 3.2V. On TB801 on hot side I have 98V on pin 1,2,4 and on pin 6 I've got 5V bot on the cold side I have 3.2V.

[@wtam69]

CN807 to CN809 should be disconnected if you are checking the Y board. To be safe, please have someone qualified to do the testing as the tv has high voltages with the back removed.

[@chrisiscrazy24]

After reading that last comment I checked my supply again. Vs reads the correct voltage as the tv starts but then it quickly drops to zero

[@iln.justinlane5764]

Hi i have tested my va and vs voltages and they are both well over what they should be, i can not turn the voltage down any further, any advice would be great

[@electricdixie34]

Hi i have a tv turn it on and it clicks and stays on with blue light...i seem to have my low voltages but nothing at VS and VA outputs..any ideas..poss regulator? all caps are ok

[@ronb7481]

But what if the Vs and Va voltages are low or zero?

[@wtam69]

Thanks. I tend to be overly cautious.

[@BATMEX44]

wtam69 Those voltages on VA and VS must be there at the time the power switch is pressed or at the time you plug the tv on the ac outlet ? My VA and VS voltages are 57.9 and 206v when switch is pressed then the voltages going down. Do you think my Ysus is bad?

[@aongolamakweti7498]

Sumsung lcd tv model LA37m86BD model code LA37m86BD/XHR Type number TU37SO switches on with no colour no picture and no sound. How do i go about repairing this set ? please help.

[@dustinwittig1290]

if I'm not getting any voltage at VS or VA is that clearly a bad power supply? i can't find any fried components, though i did find and replace a bad fuse, but that didn't fix the problem. fuse hasn't blown again yet btw.

[@wtam69]

***** Sounds like a bad power supply. Some bad components cannot be spotted by looks. Power transistors, resistors and capacitors could be the problem.

[@jerryluquin7500]

I played around with the Va and Vs on the power supply and didn't affect the sparkling the only thing that worked was the fan, would a new Y board solve this issue or is it a power supply issue, thanks so very much

[@chrisiscrazy24]

So I have a Samsung plasma that gets zero voltage on vs or va. I can get all standby voltage, 5v, and 15v. No high voltage though. Any idea what I can check on my power supply. All caps look fine except there is one cap that's 450v 10uf that feels very slightly rounded on the top, but its very difficult to tell.

[@wtam69]

Leave the fan on until the tv dies completely. The Y board is pretty expensive. If the tv doesn't power up, you'll know it's the power supply.

[@VeezyIII]

Thanks for making this video. Very informative!

[@erikdecker7226]

Hello, id be really happy if you could help me. I have a dell W4200ED that after about 20 minutes of being on, any dark images on the screen cause black/green/blue pixels to show up and start spreading towards the middle. Do you know what can cause this? thanks.

[@adamoun]

please I found on my lg plasma 50 that my VS is 223 instead of 203, and the VA is 65 instead of 60, can you please help me to fix it, thanks in advance

[@jerryluquin7500]

Hi, i have a samsung plasma pn50c7000yf, i seem to have an overheating issue with one of the boards, when its been on for a while with the back cover on i get what looks like red pixel flashes on dark areas, once i take the back off and turn on a fan it goes back to normal, if im reading correctly is this one of the boards or a Vs & Va adj problem?

[@moftsoft]

I have the same TV and after about 30 minutes, I get a sparkly horizontal single-pixel tall line in the center that sounds similar. Did you ever fix yours?

[@c1nd3r65]

My LG plasma has a red fuzzy band in the middle. I've checked the vs and va the vs is at 201 but mine is reading 202 is that ok? My vs is at 55 n that's what I'm getting. How do I gets rid of the red band on my tv?

[@wtam69]

cinder ed Try increasing the vs by a couple of volts to see if that would make any difference.

[@massivemikeh]

wtam69 I was given a 60in plasma from my folks. Had pink disortion. Adjusted VS screw clockwise by a tiny amount...Perfect picture. Thank alot mate!

[@pgice]

hey man..what does VA stands for?..i have VA and VS regultators on my Pioneer Kuro also

[@pgice]

VS should be VOL SUS but VA?

[@wtam69]

pgice VA is just the name of the signal from the VA circuit.

[@pgice]

wtam69 yes but what does it control?

[@wtam69]

pgice I believe the circuit rectifies the AC to DC.

[@pgice]

wtam69 ok great..i have some pixel sparkles near black on my Kuro..if i rasie (turn clockwise) VA ADJ i almost get rid of them..so it seems that this regulator controls the lower voltages near black level.

[@UnicornRiderNarresh]

Great video 👍

[@24zelock]

my 50" plasma when pluged in just lights up with blue light , nothing on screen at all , can here a faint clicking sound . my board is identical to yours , i have zero volts ant my vs test point , and only 0.04 volts at the vs test point , any help much appreciated , great vid by the way

[@wtam69]

Sounds like your power supply board is not working. Look for obvious signs of bulging capacitors. Those are fairly easy to replace. When they go bad, your tv won't switch on. Other components are difficult to diagnose and replace.

[@24zelock]

thanks for reply , all caps look good and no other signs of any thing looking burnt or damaged . any ideas ?

[@alolouh6785]

Thanks for sharing

[@CimiF]

I've been trying to repair my Samsung 42" plasma tv which has sound but no picture at all. At first I thought my PSU was at fault but an used unit, which I bought from Internet, never got my TV working. Does anyone here have a clue what could be the problem, when the TV's Va is normal 63 volts but there is no Vs at all? When I connect any buffer board to the PSU the Vs rises to 7 volts. If none of the buffer boards are connected to the PSU, the Vs is 0. Thank you in advance =(

[@subigirlawd_7307]

My vs voltage is rated at 177 vdc but I'm getting 234.6 vdc 😢

[@thecoinmagician]

That will kill your panel

[@gleningalsbe8351]

That voltage should be within 1-2 volts maximum. The sticker inside on your panel should tell you the exact tolerance. You can try adjusting it, but you may be better off replacing the P.S. board.

[@LunaErosStudios]

Appreciate the info but damn you're long winded.

[@wtam69]

Yeah right, let's cut to the chase.

[@airport4173]

WHY MAKE IT SO SO FUZZY......this can be dangerous.

[@Escorpio40]

Very confusing explanation.