Fluorescent Bathroom Light Issue

[Orion801]

Hi all,
I've been having some issues trying to fix a fluorescent light in the bathroom. Here's the steps I've taken so far after it suddenly stopped working:

1. Replaced bulb with identical spec part (Philips TL5C 40W). Let's call the original Bulb A, and the new one Bulb B.
No response when light turned on - Ballast A w/ Bulb B

2. Replaced ballast with non-equivalent but, according to product spec, compatible part. I'll call the original (Philips YZ-I40EAA T5-C) Ballast A and the new one (Philips HF-P I 22-42 PL-T/C/L/TL5C EII) Ballast B.
No response when light turned on - Ballast B w/ Bulb B

3. Bulb B fitted.
Light turned on (~0.5s delay) - Ballast B w/ Bulb A

4. Light cover refitted.
Buzzing and flickering when light turned on, then went dark - Ballast B w/ Bulb A

5. Bulb A and Bulb B both refitted several times, and connections checked. Bulb B never worked, Bulb A worked occasionally, but often would flicker and buzz. After several attempts to improve the connection, Bulb A also stopped working completely (and had some visible discolouration to the tube).


I'm now unable to get a response from anything. I've checked the condition of each item, and taken what measurements I can. Details below:

Bulb A: Has been seen to work earlier, but now showing discolouration and I can hear some debris moving around inside the tube. There are 4 pins, measuring across all combinations gives an open circuit reading.

Bulb B: Has never been seen working. No visual signs of any defect/damage. If I measure across pin combinations 1-2 and 3-4 I get readings of about 4.5 ohms. I get open circuit for all other combinations.

Ballast A: Wasn't working with either Bulb A or Bulb B previously. I haven't had a chance to re-check though, as now I have no bulbs that look like they're working. There are no visual signs of any issues on the circuit board when I open up the unit. If I measure across all 4 output pin combinations I get open circuit readings, and also when I measure from these to ground.

Ballast B: Was working earlier with Bulb A, before it blew, but not reliably (unclear if ballast problem or loose bulb fitting connection). Readings across output pin combinations and output pins to ground are all open circuit.


Does anyone have any idea what could be going on here? The new ballast did have slightly different output wiring positions, but I believe I connected these all up correctly. The only one I wasn't 100% sure of was for the 4 output pins as the diagrams/markings didn't match up too clearly between old and new, but would assume if I'd got this wrong that I would never have seen any bulb light up?

Any advice is appreciated. For now all I can think of is to just try a new ballast and bulb combination simultaneously, and hope I can return Bulb B and/or Ballast B to the shop.

EDIT: Forgot to mention, I've measured the mains input to the ballast and all looks to be as expected. I also checked continuity between the bulb pins and ballast output terminals when it was fitted to check the quality of the bulb fitting connection.

 

[DPG]

Personally I would replace the whole thing for an LED fitting. This will perform better and take less power.

 

[SJD]

Personally I would replace the whole thing for an LED fitting. This will perform better and take less power.

And be working in far less time than all this swapping of lamps and ballasts must be taking.

 

[ipf]

It's a 'tube' or a 'lamp', even.....not a bleedin' BULB......

As 'The Saint', Roger Moore had one of them above his head....

 

[pirate]

Maybe a dumb question, but have you changed the starter?

 

[Orion801]

Thanks for the responses guys. I've had a look but unfortunately there's no direct LED replacements that I can find that will fit into the same lamp housing. I could replace the whole unit, but would prefer not to if I can avoid it. A good back-up plan though if I can't fix this one.

As far as a starter goes, I believe in this system it's built into the electrical ballast.

 

[brianmoooore]

Is the replacement ballast the correct wattage for the lamp? If so, your best course of action is to buy a new one, fit it, and prove that the lamp works, then refit the first ballast you bought, and prove that it doesn't work again. At that point you have proved that this ballast is faulty, so can be returned to the supplier for a refund.

 

[DPG]

Any reason why you don't want to just replace the unit with an LED replacement. It is going to save you time and money, and will look better.

 

[i=p/u]

Sometimes new ballasts comes with less connections, ie two have to go in connector.