Faulty MPF7409 PSU from Hitachi pd5200 plasma.

[littlejon]

Hi, thought I'd post my problem in here on the off chance someone can help. I been trying figure out why my TV makes a clicking noise under load (when brightness and colour etc are turned up) it doesn't do this when all setting are low.

I've figure out the clicking is (I think) coming from inductor I think that's what it's called, biggish component 4cmx4cm with coils rapped around something.

I've got some answers on this, one chap reckons I should replace 2 caps and resolder some connections, there's the thread if any ones interested:http://www.tv.quuq.org/forum/index.php?topic=6669.0

Any thoughts on this before I try to fix it.

Thanks Jon.

[tom66]

Re: Faulty MPF7409 PSU from Hitachi pd5200 plasma.

Use some varnish on the inductor to glue the coils together - common fault...

[littlejon]

Re: Faulty MPF7409 PSU from Hitachi pd5200 plasma.

Really wow that would be handy, will give it a go. Thanks. don't suppose you can give some more info on this.

Are the inductors pretty solid, is it all right to remove the protective tape and get inside it.

[tom66]

Re: Faulty MPF7409 PSU from Hitachi pd5200 plasma.

Really wow that would be handy, will give it a go. Thanks. don't suppose you can give some more info on this.

Are the inductors pretty solid, is it all right to remove the protective tape and get inside it.

Don't know why I said varnish!

Just use super glue - the coils are normally glued at the factory but it dries out and becomes brittle leading to a whining inductor. No need to remove the tape, just pour it through it. Though I'd expect the whining to be from the sustain boards, not the PSU.

[littlejon]

Re: Faulty MPF7409 PSU from Hitachi pd5200 plasma.

No this is def the PSU board, it's not a whining or buzzing noise more a fast clicking that speeds up when load it put through the PSU. (turning brightness to full).

If a grip the inductor it dampens the noise, I could be mistaking a whining noise for a clicking noise but to be honest its much more clicky then whinny.

[tom66]

Re: Faulty MPF7409 PSU from Hitachi pd5200 plasma.

No this is def the PSU board, it's not a whining or buzzing noise more a fast clicking that speeds up when load it put through the PSU. (turning brightness to full).

If a grip the inductor it dampens the noise, I could be mistaking a whining noise for a clicking noise but to be honest its much more clicky then whinny.

Might be internal arcing then - difficult to fix...

[littlejon]

Re: Faulty MPF7409 PSU from Hitachi pd5200 plasma.

Yer I read that some where else too, if it's arcing is it still down the the inductor or some odd voltages going through it?.

Would replacing the unit sort the problem out.

[tom66]

Re: Faulty MPF7409 PSU from Hitachi pd5200 plasma.

Replacing the PSU is likely to fix it, but it is expensive. Finding that inductor could be nearly impossible.

[littlejon]

Re: Faulty MPF7409 PSU from Hitachi pd5200 plasma.

Yer there 59+post on ebay. not worth it.

As for finding the correct inductor (I have been looking) any tips, shame really silly little thing to replace but impossible to find.

Thanks for all the help much appreciated.

[littlejon]

Re: Faulty MPF7409 PSU from Hitachi pd5200 plasma.

Would epoxy dampen the noise a little?.

[tom66]

Re: Faulty MPF7409 PSU from Hitachi pd5200 plasma.

Would epoxy dampen the noise a little?.

Possibly - worth a shot.

[selldoor]

Re: Faulty MPF7409 PSU from Hitachi pd5200 plasma.

Did you try the superglue? shouldnt do any harm even if it doesnt work.

Are there any numbers on the inductor - how about a close up picture then we can all look.

[littlejon]

Re: Faulty MPF7409 PSU from Hitachi pd5200 plasma.

Hay , will try the super clue today, my camera's out of action, here's one of the hole board, the noisy inductor is top left near the 2 big caps.

I've had a good look at it (haven't taken it out of the board) not shore weather taking it out will help?seems to look all right.

The only number on it is 1v001 E3YR have no idea what that means (some sort of voltage maybe).

Would a close up picture help more.

This super glue idea, should I remove the yellow tape to get to the coils or remove the inductor to get better access.

The help is appreciated at least I'm getting somewhere.

[littlejon]

Re: Faulty MPF7409 PSU from Hitachi pd5200 plasma.

Well the super glue didn't help, what are my chances of finding a replacement. I have been looking but like tom said could be impossible but I must try.

I'm going to look into fixing the arcing but again this might proof very hard.

Any more tips before I junk it.

[tom66]

Re: Faulty MPF7409 PSU from Hitachi pd5200 plasma.

This PSU is cross compatible with a lot of other LG power supplies, maybe you could sub it for one of those...

[littlejon]

Re: Faulty MPF7409 PSU from Hitachi pd5200 plasma.

Hay tom, just come across this, Tip:
LOUD TICKING NOISE FROM PSUSYMPTOMS :
Set works normally but very loud ticking noise emanating from the Power supply panel.
CURE :
Replace Electrolytic capacitors C016 and C201 on the Power supply board.
IRISPart:
TS04905Electrolytic Capacitor 270mf 400Volts
Reference:
C016,C201
Section:
PSUPower supply

Does this sound correct, could they be worn but show no signs of it. I take it the caps can not make a clicking noise. I have no way of testing them at the moment.

If the caps are bad then this makes sense, what do you think.

[tom66]

Re: Faulty MPF7409 PSU from Hitachi pd5200 plasma.

Hay tom, just come across this, Tip:
LOUD TICKING NOISE FROM PSUSYMPTOMS :
Set works normally but very loud ticking noise emanating from the Power supply panel.
CURE :
Replace Electrolytic capacitors C016 and C201 on the Power supply board.
IRISPart:
TS04905Electrolytic Capacitor 270mf 400Volts
Reference:
C016,C201
Section:
PSUPower supply

Does this sound correct, could they be worn but show no signs of it. I take it the caps can not make a clicking noise. I have no way of testing them at the moment.

If the caps are bad then this makes sense, what do you think.

Hmm. Possibly, it could be an unstable PFC circuit producing the sounds. You can get some new caps here: http://uk.farnell.com/panasonic/eetu...00v/dp/1198679

Check what the original capacitors were - brand and series - so an exact match can be found.

[littlejon]

Re: Faulty MPF7409 PSU from Hitachi pd5200 plasma.

Thanks for the link, I didn't really understand the PFC circuit bit...the sound is def coming from the inductor no question about it.

If the caps where not doing there job then this could lead to the inductor getting to much current, making the clicking noise (does that make sense)?.

I am a total newbie here so bear with me.

[tom66]

Re: Faulty MPF7409 PSU from Hitachi pd5200 plasma.

Thanks for the link, I didn't really understand the PFC circuit bit...the sound is def coming from the inductor no question about it.

If the caps where not doing there job then this could lead to the inductor getting to much current, making the clicking noise (does that make sense)?.

I am a total newbie here so bear with me.

Basically the PFC circuit's job is to satisfy European bureaucrats . It is supposed to make the input current a sine wave to match the supply voltage. In the ideal world, it would not be necessary.

It still seems strange to me, but someone has posted that because it solved their problem. I do know bad caps on the PFC can cause the PFC circuit to become unstable, but the clicking sounds weird. The only way to be really sure is check with an oscilloscope.

[littlejon]

Re: Faulty MPF7409 PSU from Hitachi pd5200 plasma.

Thanks for that, I got the info from here:http://www.scribd.com/doc/28551796/4...0-Service-Tips

It would help if it that link provided a little more detail like where the sound is coming from, it just ses clicking noise from PSU board.

Can't decide weather its worth giving it a go..replacing the caps is easy so I might try.

Regarding the caps this is every thing written on it:

(M)
HC CE(M)
105 C
270UF
400V
Japan

Would the one you linked me to do the job, the only difference is the max temp is slightly lower 85 c as for all the other value's I have no idea.