Pioneer Plasma Kuro KRP-500M - Zapping noise

[MetallicA]

Hello all,

I've been having a weird issue with my Pioneer plasma, it hasn't been used much (around 600 hours on it), but it recently started to make this weird zapping electrical noises (pretty much like what you'd hear from a bug zapper lol), here's a sample I recorded when switching on my TV:

https://soundcloud.com/metallicaband/krp-500m-noise

Sound quality is pretty poor since I recorded with my phone, so please crank up the volume a bit to hear it properly.

The noise is very noticeable during the TV's startup but after around 10-15 seconds once the unit has fully booted it becomes barely noticeable unless the HDTV switches the source signal where it becomes apparent again, like going from 720p to 1080p, after that there are tiny zapping noises every once in a while but it's not consistent the way it is during startup like the sound clip I mentioned.

I couldn't locate the sounds from a specific place of my Plasma, it comes from throughout the panel, but I can hear it more clearly in the upper left and lower right corners, I really have no idea if specific circuit boards are causing the noises or something else.

Things that I've already tried to solve the problem:

- Tried changing the power cord
- Unplugged all video cables (HDMI..etc)
- Tried different power strip
- Made sure all screws are tightened in the back cover to make sure there are no vibrations or anything like that.
- I moved the TV to my living room (where I have another Kuro (5020FD) which doesn't have this issue) and connected it to the same power source there to make sure the problem wasn't caused by my room's circuit or any other thing causing an interference.
- Switched between the TV's power save modes, that only helps reducing the regular Plasma "buzz noise" but not the abnormal zapping noise I'm having.

None of the above worked, the zapping noise remained exactly the same, very apparent during startup then it fades away to little noises every once in a while unless I'm switching signals.

I can try disassembling the unit, but I really have no idea what to look for, even though I've disassembled my 5020FD Kuro before to install the "e-lite" board mod so I have an idea about how to do it, I don't feel comfortable switching on the unit while it's disassembled to see what's causing the issue.

I'm not using the unit at the moment because I fear neglecting the issue will cause a more serious hardware failure in the future.

Any help would be much appreciated.

[freakaftr8]

Re: Pioneer Plasma Kuro KRP-500M - Zapping noise

Does the screen change with the zapping noise when. It happens?

[MetallicA]

Re: Pioneer Plasma Kuro KRP-500M - Zapping noise

No it doesn't, picture remains normal.

[freakaftr8]

Re: Pioneer Plasma Kuro KRP-500M - Zapping noise

Can you tell if it is coming from the right or left side or the center of the tv?

[freakaftr8]

Re: Pioneer Plasma Kuro KRP-500M - Zapping noise

Sorry reread the posting. It.sounds.like an arcing issue. Is it dusty? It sounds like a high power circuit is arcing possibly bad solder connection. You really need to look down the vent holes with the lights off.to see if you can see the arcing. Or.take the cover off and lis ten and look for arcing.

[Pumpkin]

Re: Pioneer Plasma Kuro KRP-500M - Zapping noise

Hey, I have the same issue since yesterday, I own the KRP500M for about 5 years, I have heard your audio file, it is exactly the same issue. Have you managed to solve it? if so can you please post me what were the findings and how did you solve it?

Many thanks

[Ltank]

Re: Pioneer Plasma Kuro KRP-500M - Zapping noise

Unplug set. Wait about 5 minutes then carefully remove the rear cover. Look for arcing on
Power supply and the Y board (left) and X board (right) that is looking from the rear of the
Set. Arcing can also be on the underneath the boards on the foil side. Look for Burt connectors too. Take some pics.

[Pumpkin]

Re: Pioneer Plasma Kuro KRP-500M - Zapping noise

Hi, Thanks for your prompt response. If I understand correctly I need to unplug TV, wait 5 minutes, take off back cover, connect to AC and look for electrical arcs. am I right?

Thanks

[Ltank]

Re: Pioneer Plasma Kuro KRP-500M - Zapping noise

yes

[Ltank]

Re: Pioneer Plasma Kuro KRP-500M - Zapping noise

look for burning first. if you dont see where it is arcing then plug it in and turn it on

[Alastair E]

Re: Pioneer Plasma Kuro KRP-500M - Zapping noise

--Dont forget the Anti-Tamper switch....

Some sets are fitted with them--some not....

Set will not fire up with rear-cover removed if it has the anti-tamper, and I believe there's a procedure to re-set this, as the set will not fire up--even when cover is re-fitted...

[Chippy99]

Re: Pioneer Plasma Kuro KRP-500M - Zapping noise

Hey, I have the same issue since yesterday, I own the KRP500M for about 5 years, I have heard your audio file, it is exactly the same issue. Have you managed to solve it? if so can you please post me what were the findings and how did you solve it?

Many thanks

I have the exact same issue with my KRP-500A. It just started last night making these loud arcing / crackling noises. As far are I can tell, the picture is still perfect, but the TV sounds like it is about to expire.

Did anyone manage to discover the cause and how to fix this?

Thanks

[ReeceyBurger123]

Re: Pioneer Plasma Kuro KRP-500M - Zapping noise

I have the exact same issue with my KRP-500A. It just started last night making these loud arcing / crackling noises. As far are I can tell, the picture is still perfect, but the TV sounds like it is about to expire.

Did anyone manage to discover the cause and how to fix this?

Thanks

Turn the tv on put your ear to the back cover and see what part the noise is coming from, Left, Right or Centre ?

[tom66]

Re: Pioneer Plasma Kuro KRP-500M - Zapping noise

I've had this exact same fault occur when I set the VOL SUS too high on the config menu on a few PDP-LX5090s. It's the PSU hiccupping because it's hitting power limit. Doesn't cause any problem with the image (probably due to the enormous amount of bus capacitance.)

Two fixes; You can lower the contrast setting in the user menu. May not fix buzzing for all patterns and can significantly darken the image.

Or a better fix connect RS232 cable to panel, enter service menu using sequence "FAY" command (instructions online) and set VOL SUS and ABL settings down until it no longer ticks on full pattern white (MKR S01, iirc, you can type command in and alternate to set correct VOL SUS.)

I have a full command guide - will upload when I find it.

[ReeceyBurger123]

Re: Pioneer Plasma Kuro KRP-500M - Zapping noise

Wow Tom you know everything about Kuros haha !!!!

[Chippy99]

Re: Pioneer Plasma Kuro KRP-500M - Zapping noise

Thanks guys - really appreciate your thoughts. As to where the sound is coming from, it's really difficult to tell because the panel in wall mounted, but if I had to guess, I would say the middle.

I have a few other data points to add:

1. The noise is not constant, i.e. It doesn't do it constantly. It will crackle for perhaps 20 or 30 seconds, stop for a while and then do it again after another 20 or 30 seconds. It seems pretty random and is not content-related, i.e. it doesn't matter what's on screen. Even a pure black screen will do it.

2. The contrast setting makes no difference, and neither do any of the power saving settings. It still does it in Eco settings.

3. It does it from cold. Last night when this first happened, I had been watching for hours and the TV was hot. I was hoping from cold boot it would not do it, but it does. Within a minute or so of power on, the panel is crackling/fizzing loudly. It's MUCH louder than the normal panel "buzz" that all Kuros do.

I should also mention that having now listened to OP's sound clip, mine sounds nothing like that. Mine is a loud fizzing/crackling. It's a bit like the normal panel sound, but much much louder and it also crackles and is a more "scratchy" sound, if that makes any sense? A bit like an arc welding sound.

Do you think this is the PSU about to go belly up?

[tom66]

Re: Pioneer Plasma Kuro KRP-500M - Zapping noise

Hm, could be anything then, hard to be sure. If you have a computer with an RS232 port, or a USB to RS232 connector, you can try entering the service menu of the TV and checking the settings to see if you can rectify the fault.

[RJARRRPCGP]

Re: Pioneer Plasma Kuro KRP-500M - Zapping noise

Sounds a lot like the primary side arcing. And it didn't sound like 50 hz, LOL.

It makes the same kind of sound as the 2006 RCA CRT TV that's on the porch.