fluorescent tube failure

Postby mlee2 » Mon Jan 14, 2008 9:41 pm

hi all,

i am about to pull my hair out! please help!

i have a fish tank with a built-in fluorescent tube inside the lid unit.

i know its a strange one to ask, but i am not sure if all tubes behaves the same way, be it for the house or for a fish tank.

I had the tank since feb 06, and the light worked ok as usual.

the just before x'mas, it basically dimmed to half of its brightness. The tube ( about 8 inches long) had both ends 'burned' inside.

it still worked, but it flickers from bright to dim.

ok, bought a replacement tube soon after. Then it happened again over the weekend.

thinking it was bad luck with the tube, i went to a local place that also stock the factory brand and bought another new tube.

i put it on, went to the gym and yes, it went again. same problem. Dim but inside either end looked burned.

The tube is inside the whole lid console unit, and is protected from moisture.

i am no great electrician, but don;t know where has it gone wrong.

please help.

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Joined: Sun Dec 23, 2007 12:37 am


Simply Build It

Postby 333rocky333 » Mon Jan 14, 2008 11:41 pm

The lamp is proberly not connected direct to the mains supply, it is usually controlled by a small unit which adapts the mains first to run the light.

It may be electronic or possibly have a starter lamp with it that needs replacing.

Follow the leads from the lamp they will lead to the control unit, that runs the lamp, this unit may be worn out and needs replacement.

These small lamps do go black at ends but usually still run for a while .
But it does sound possibly like the unit is going allowing too much current through the ends causing premature failure and excessive blacking to the ends.

Also check the WATTAGE on the lamp matches what is on the unit.

Isolate supply first.
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Joined: Sun Nov 25, 2007 11:03 pm

Postby mlee2 » Wed Jan 16, 2008 12:17 am

thanks 333rocky333,

these units are all 'seal' up and hard to get to. never the less, i will try.

its not rubber sealed as such, just all screwed together tightly. Its not dangerous to unscrew the bits.

might be harder to get the bits for replacement.
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Joined: Sun Dec 23, 2007 12:37 am

Postby ericmark » Wed Jan 16, 2008 11:29 am

It looks as if your unit is poted. That is after it is made it is filled with something to stop water and any maintainance. Never the less what Rocky says still is correct but looks as if only cure is complete new unit.
One thing Rockey did tell you was to check on tube size. For specialist tubes often the wattage is greater than tube the same physical size for standard use. And if for example designed for 11 watt and you fit an 8 watt then you will get the problem you describe. Often with fish tank units there is no fitting as such just two plugs and longer or shorter tubes can physical be plugged in but will not electrically be compatible. Also some are thicker than others. Do therefore check the details on unit match details on tube.

Postby 333rocky333 » Wed Jan 16, 2008 8:06 pm

Thought I recognised the name
Remember your laptop/extension lead.!!!!!!!!!!!
Posts: 182
Joined: Sun Nov 25, 2007 11:03 pm

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