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39pf 6kv ceramic cap - 37" LCD TV Inverter/Power b/d

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notallbad

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Where to source the above, and why so expensive? (Please note location, sourcing in the UK is never easy nor cheap!)

Alternatively a combination to connect in parallel to equate 39pf (i.e. 27 and 12).

Would like to buy 2 of each as its possible there may be further issues and may just blow again but the simplest solution is to replace this obviously burnt out cap first then proceed.

The 37" LCD TV turns on but clearly no back light, then goes into power cycling.

The cap is on an Inverter/Power supply board and connected to a transformers secondary output side. I'm guessing the signal side to indicate the BL_ON.

No other investigation done other than a visual inspection.

**broken link removed**

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Failure of these capacitors is relatively common - but they are almost impossible to source.

CHS list 5pF, 27pF, 33pF and 47pF

**broken link removed**
 
So it would seem!

If I were to place 2 in parallel how close to 39pf do they need to be?
Would
22 and 15 = 37
or
33 and 5 = 38

be sufficient?
 
To place 2 caps in parallel would it be ok to
Option 1 : solder one cap in place of the burnt out one (so directly to the board, through-hole) and solder the legs of the 2nd cap to the legs of the first?
Or would it be better to
Option 2 : solder the 2nd on the solder side of the board, there is enough clearance behind the board though will need to be laid flat to the board with a piece of insulating tape between the cap and PCB.
Personally I think option 2, will look more professional too!
Hope this makes sense.
 
Option 2 would place 6kV very close to the PCB tracks. Is your insulating tape up to the job?
 
Don't put it on the back of the board - there are enough problems with LCD inverters arcing from the back of the PCB to the metalwork as it is, without moving the HV closer to it.

If you want to be particularly neat, then drill a couple of extra lead holes through the board (obviously so they go through the same traces), and solder it there.
 
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