Electronics Gurus Advice Needed Please

[ro63rto]

I need to replace some capacitors on the power board of my LCD TV as they have bulged and caused the picture to fail.

Where is the best place to buy quality replacements and is there an easy way to remove them?

[clockboy]

http://www.maplin.co.uk/search?text=Capacitors

This could be a good place to look.

[ro63rto]

http://www.maplin.co.uk/search?text=Capacitors

This could be a good place to look.

I was in one of their stores the other day. Nothing on the shelves and their paper catalogue didn't seem to list some of the higher value ones I need.

I'll check their site in case it lists more.

Thanks.

[Tex]

I'd order online (with free delivery) from http://uk.farnell.com/

 

Panasonic FC series would be what I would go for as a reasonably priced but better quality replacement. Just make sure the voltage rating is the same or higher.

 

Fortunately the board looks to be single sided so removing them is easy. Just heat one lead at a time with a soldering iron while gently pulling the capacitor away from the board (you can rock them slightly while doing this as it can help as sometimes they are glued down). Alternate the soldering iron between the leads while pulling and it should gradually lift away and eventually off the board. Don't pull too hard or heat one lead for too long as this can damage the board. If there's any solder left on the pads you can use solder wick to remove it. Then solder in the replacement part.

 

For the 470uF 25V capacitor (I can't see the value of the other one) Farnell have two possible replacements:

http://uk.farnell.com/panasonic-electronic-components/eeufc1e471l/cap-alu-elec-470uf-25v-rad/dp/1855169

http://uk.farnell.com/panasonic-electronic-components/eeufc1e471/cap-alu-elec-470uf-25v-rad/dp/9692169

 

The difference is the lead spacing. It's best if you measure the space between the leads of the existing part and choose the closest match. If they are slightly different then can be bent to fit.

[clockboy]

I was in one of their stores the other day. Nothing on the shelves and their paper catalogue didn't seem to list some of the higher value ones I need.

I'll check their site in case it lists more.

Thanks.

At their Lakeside store (Essex) there is a counter with a  good stock and a guy who helps.

[ro63rto]

I'd order online (with free delivery) from http://uk.farnell.com/

Panasonic FC series would be what I would go for as a reasonably priced but better quality replacement. Just make sure the voltage rating is the same or higher.

Fortunately the board looks to be single sided so removing them is easy. Just heat one lead at a time with a soldering iron while gently pulling the capacitor away from the board (you can rock them slightly while doing this as it can help as sometimes they are glued down). Alternate the soldering iron between the leads while pulling and it should gradually lift away and eventually off the board. Don't pull too hard or heat one lead for too long as this can damage the board. If there's any solder left on the pads you can use solder wick to remove it. Then solder in the replacement part.

For the 470uF 25V capacitor (I can't see the value of the other one) Farnell have two possible replacements:

http://uk.farnell.com/panasonic-electronic-components/eeufc1e471l/cap-alu-elec-470uf-25v-rad/dp/1855169

http://uk.farnell.com/panasonic-electronic-components/eeufc1e471/cap-alu-elec-470uf-25v-rad/dp/9692169

The difference is the lead spacing. It's best if you measure the space between the leads of the existing part and choose the closest match. If they are slightly different then can be bent to fit.

Thanks.

I'll note down the others and search.

Some are 1000 others are 2200.

Does it matter if I get a higher voltage?

Ie instead of 10v --》12v?

[ro63rto]

At their Lakeside store (Essex) there is a counter with a good stock and a guy who helps.

Sounds like its miles better than my local one as well as being miles from me [emoji16]

My one just grunted and pointed to the catalogue saying "try there" when asking what they stocked.

[Tex]

Does it matter if I get a higher voltage?

Ie instead of 10v --》12v?

 

It certainly doesn't matter going from say a 10V rated part to a 16V rated part which is one level up. There's no benefit from going with a higher voltage rating you just can't go lower. I would also avoid going too much higher (100V etc.) because the chemistry inside and hence the electrical properties can start to vary. I suspect you should be able to find the parts you need with the same or slightly higher rating fairly easily.

 

The electrolytic capacitors in LCD TV's, computers, etc. are typically the low ESR (equivalent series resistance) type. The Panasonic FC series I recommended are low ESR (there are many others it's just that Panasonic FC is as common as dirt). The ones from Maplin may or may not be low ESR and it's best to check as standard ESR parts may not work at all or could fail very quickly.

[ro63rto]

Thanks Tex. [emoji106]

This swap out of all seven (just to be sure) capacitors should be fun and a lot easier than trying to source and fit a replacement slava 2427 rotor mount [emoji16]

[Tex]

No problem.

 

Just be sure to be safe as there can be some nasty voltages around the power supply. It also goes without saying that electrolytic capacitors are polarised and so the negative stripe on the new caps have to go the same way as the ones that were removed. It's a good idea to take photos and double check because even when the polarity is marked on the board you can't always trust those markings to be correct. I know this from replacing 53 caps in a stereo amplifier a few months ago.

[ro63rto]

I've taken some but will draw out on graph paper the values and polarity etc. [emoji106]

I'm very wary when working on electronics ever since I picked up an uncased radio without noticing some eejut had plugged it back in. Shot me back 7ft [emoji35] and gave me a numb arm for a few days.

[ro63rto]

Received one of the capacitors today.

Spec is the same but its almost half the height of the original.

Does it matter?

[Tex]

No it's not important. The Panasonic ones often are smaller.

[ro63rto]

No it's not important. The Panasonic ones often are smaller.

Ok thanks.

Wish me luck [emoji1]

I hope its just the one I need to xhange and not the other 6-7 [emoji16]

[Tex]

To be honest it's worth replacing them all while you have the thing apart. The component cost isn't particularly high, they don't always show physical signs of failure and it looks like the originals aren't good quality brands in this case.

[ro63rto]

To be honest it's worth replacing them all while you have the thing apart. The component cost isn't particularly high, they don't always show physical signs of failure and it looks like the originals aren't good quality brands in this case.

True.

I'll fit the others too.

[ro63rto]

[emoji35] Fitted the 470uf 25v one then my portable gas fired soldering iron ran out of gas! Can't find my electric one I used to repair vacuum ckeaner motor last month.

Curiosity got the better of me so I tried it anyway.

No difference. Sound and backlight but no picture [emoji20].

[ro63rto]

Small update.

All caps replaced. No change.

Spoke to several tv repairers. General consensus is that the T-con board is faulty.

Ordered a tested second hand one guaranteed for 3 months. Should arrive on Monday. Fingers crossed.

[ro63rto]

Finally fixed! [emoji16]

Old Tcon

Partly disassembled

Replacement Tcon

No pic of a working TV cos you all know what that looks like and it'd be boring daytime TV [emoji12]