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Testing CCFLs

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OldLes:
I have been looking at "the other forum" where I came upon a reference to a tester for CCFLs, which I see can be purchased from Chas Hyde in the UK. At £100, rather more than I am inclined to pay.
I am sure somebody will have taken an old inverter board, cut it down somewhat, and found a way to use it as a CCFL tester.
I have a 42" Sharp with at least three faulty tubes, but with 18 in there, not easy to locate which ones, dismantle and remove and replace the correct ones.
So, has anybody made such a tester, and if so, what was involved?
OldLes.

fix2003:
try ebay
400349118892

Keith:
Hi Oldles,

I have one like the one Fixitnow has linked to and it is only good for up to 20"

This is better I think, 150948891826 on Ebay. I am in fact waiting for one to turn up.

You could modify an inverter board by disabling the protection circuits, again which I have, I just want something more easier / convenient to use.

Testing CCFLs is not 100% with any tester. These testers, including the £100 ones, only really show how the lamp lights. If the lamp lights with pink or blue tinges it duff! But the lamp may be drawing excessive current which will cause a protection fault and  the drive IC to shut down. So it is also necessary to measure the current for each lamp. Also, these testers can not detect a slow starting tube. The drive IC expects the tubes to strike and start within a specified time, if one doesn't, again the drive IC will go into protection.

When mine turns up I will let you know if works OK

Keith

downunder:
Go to www.shop.television-magazine-forum.co.uk and check out their EMR Diagnostika.
Available for 40 pounds in the UK.

Keith:
The EMR Diagnostika only checks that the inverter circuit is working, in the same way that if you put your scope probe near the transformers to detect any EMR. It doesnt test CCFL tubes.

Keith

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