Technika 32-407B starting problems

[riget]

Hi, got this tv that had starting problems, it would take several attempts to start, I found a cap leaking on the power board, so I changed 6 caps that I found on another site(can't find it now) said needed changing.
It has been ok for a couple of months but now has starting problems again, this time the sound always starts but no picture, and you get a banging type noise, the hdmi logo will show but it will be dull, if it goes bright then the tv starts ok.
I've found this pic of the power board on the net http://www.lcdtvparts.co.uk/index.ph...image&pID=1400
The caps I changed are the six to the right, not the two at the top/right.
If anyone can give me help with the faults I've described before I get the tv back, it would be great.
Thanks.

[PlainBill]

Re: Technika 32-407B starting problems

Hi, got this tv that had starting problems, it would take several attempts to start, I found a cap leaking on the power board, so I changed 6 caps that I found on another site(can't find it now) said needed changing.
It has been ok for a couple of months but now has starting problems again, this time the sound always starts but no picture, and you get a banging type noise, the hdmi logo will show but it will be dull, if it goes bright then the tv starts ok.
I've found this pic of the power board on the net http://www.lcdtvparts.co.uk/index.ph...image&pID=1400
The caps I changed are the six to the right, not the two at the top/right.
If anyone can give me help with the faults I've described before I get the tv back, it would be great.
Thanks.

What brand and series of capacitors did you use?

PlainBill

[riget]

Re: Technika 32-407B starting problems

Hi, I'm not sure, I bought the best I could find on ebay, some were listed as panasonic but never had panasonic printed on them, I've just looked at my stock and I think some were called Suntan cd287, and some SD cd263
Do you think it could be the same fault, I don't mind redoing them if these caps are not good enough.
Thanks.

[PlainBill]

Re: Technika 32-407B starting problems

Hi, I'm not sure, I bought the best I could find on ebay, some were listed as panasonic but never had panasonic printed on them, I've just looked at my stock and I think some were called Suntan cd287, and some SD cd263
Do you think it could be the same fault, I don't mind redoing them if these caps are not good enough.
Thanks.

It could be. There are several problems with "the best I could find on ebay". First, eBay is full of people selling counterfeit caps, reportedly only one eBay seller is reliable. Certainly I would be suspicious of a seller in Hong Kong who claimed to be selling Panasonic caps.

Second, even buying genuine Panasonic caps is no guarantee that they will last. the vast majority of Panasonic (or any other brand) caps are unsuitable for this application. The caps must also be suitable for use in a SMPS power supply. For Panasonic, that means FM Fr, and possibly FC series

PlainBill

[riget]

Re: Technika 32-407B starting problems

Ok cheers PlainBill,
Where would be best to get the caps from, I'm in uk, and what do I look for them to be suitable, I went for 105c low impedance, would buying from a shop be better/

Thanks.

[PlainBill]

Re: Technika 32-407B starting problems

Ok cheers PlainBill,
Where would be best to get the caps from, I'm in uk, and what do I look for them to be suitable, I went for 105c low impedance, would buying from a shop be better/

Thanks.

Hopefully one of the many gentlemen (or even one of these who isn't) from the UK who frequent this site will offer suggestions. RS, Farnell, and Maplin? are some of the suppliers I recall being mentioned.

PlainBill

[riget]

Re: Technika 32-407B starting problems

cheers bill, I've ordered a full set and more from Farnell, mainly rubycon, I picked the best I could see, at least I'll know if it's the caps.

Thanks.

[PlainBill]

Re: Technika 32-407B starting problems

cheers bill, I've ordered a full set and more from Farnell, mainly rubycon, I picked the best I could see, at least I'll know if it's the caps.

Thanks.

Statements like that give me the chills. There are half a dozen brands of caps that are reputed to be good. The most widely available are Panasonic, Rubycon, United Chemicon, and Nichicon. I happen to prefer Panasonic; I won't quibble with anyone who prefers others of these brands.

In the Panasonic line FM, FR, and FC are suitable for use in a switch mode power supply, M, RB, and NHG are not. Presumably a similar situation exists in the Rubycon line.

PlainBill

[riget]

Re: Technika 32-407B starting problems

I got one panasonic that's FM series, the rest are Rubycon ZL/ZLH/ZLG/ZLJ
Any idea if the ZL's are ok?

Thanks.

[PlainBill]

Re: Technika 32-407B starting problems

I got one panasonic that's FM series, the rest are Rubycon ZL/ZLH/ZLG/ZLJ
Any idea if the ZL's are ok?

Thanks.

I should have done this earlier; my bad. The 'What Caps Should I Buy' thread in the 'Frequently Asked Questions' section has the answers. They don't list the ZLJ series, so I looked it up. At a quick glance, they are good.

PlainBill

[riget]

Re: Technika 32-407B starting problems

cheers for your time Bill, I'll post back with the results in a day or two.

Thanks.

[tom66]

Re: Technika 32-407B starting problems

Rubycon ZL* series caps are very good. Almost too good for a TV power supply. Low ESR caps are important, but even a less than superb low ESR cap would probably be fine, and cost less too. Remember the originals were probably garbage. IMO, lifespan is more important than ultra low ESR in this kind of application.

[riget]

Re: Technika 32-407B starting problems

Ok got the caps(very quick service from farnell) fitted them and still the same, so it seems the caps on the power board are not the problem, unless it's another that's not been changed.
I've just tried a few things and I'll post back later, as I need the tv to cool down before trying again.

Thanks.

[riget]

Re: Technika 32-407B starting problems

Still no good, I thought I found something as I tried the scart connection instead of the hdmi and it worked, but it seems it was coincidence as it's back to the same problem.

What's happening is, when you turn on, the power light flashes for about 10 seconds, then the hdmi signal comes on the top right, then it should go bright and the picture and sound comes on, if you have no signal a yellow "hdmi no signal" comes in the centre, but you can see it's not bright enough, when you have a signal the sound comes on sometimes, other times it makes a noise like a tuned car engine, after several attempts to start it does eventually start, it then works fine till the next time you turn it on.

Thanks.

[riget]

Re: Technika 32-407B starting problems

Got it sorted, I checked best I could all the connections, I resolder as many as possible, one smd cap looked like it could have been a cold joint,
anyway put it together and starts first time every time now.

[beemerbruser]

Re: Technika 32-407B starting problems

HI,
I was reading your post about the issue you eventually solved. I have the same TV exhibiting the same symptoms. Can I ask you a couple of question?

1. In your final post, did you check all connections to all the boards & solder all connections on all the boards too or just the PSU?
2. Can you try to direct me to the SMD cap that you reckon could have been at fault too?
3. Was your PSU PSA-218-417-R? If so, which caps did you end up replacing?

Thanks a mil,
Steve

[riget]

Re: Technika 32-407B starting problems

This is going back a while, the best I remember is:
1. Just the psu
2. Sorry no, can't remember
3. It was the one in the pic, replaced the caps down the right side,
The original fault was the caps, but after the second fault and changing all the caps it was the same, I just went all over with my iron and it must have been a bad joint.
Thanks.

[beemerbruser]

Re: Technika 32-407B starting problems

Thanks for the response. Yes, mine is the same as pic so I'll replace the same caps & go over the solder joints too. I'll post up here on how I get on as there may be others out there in the same boat.

[mesersmith]

Re: Technika 32-407B starting problems

I have a problem with the same power board.
My simptoms is that the board doesn't start at all.
I look everywhere for a schematic of this, but no luck.
Somebody on this forum knows something about this?

[stj]

Re: Technika 32-407B starting problems

power supplies that wont start - start by replacing startup capacitors.
they are usually under 100uf