The fluorescent lamp on a Kenmore Model 250 stove (now
20 years old) has started wrecking new fluor. tubes
(Sylvania, 22-inch, 18 watts). Symptoms a
1. Dark grey bars appear at both ends of the new tube
within 5 min. use.
2. Tube lights only at the two ends (dark in the middle
for 18 inches.) One end shows white light, the other pink light.

What does this mean?

--
Don Phillipson
Carlsbad Springs
(Ottawa, Canada)

Don Phillipson wrote:
The fluorescent lamp on a Kenmore Model 250 stove (now
20 years old) has started wrecking new fluor. tubes
(Sylvania, 22-inch, 18 watts). Symptoms a
1. Dark grey bars appear at both ends of the new tube
within 5 min. use.
2. Tube lights only at the two ends (dark in the middle
for 18 inches.) One end shows white light, the other pink light.

What does this mean?

Hi,
The tube is worn out.

On 11/24/2012 1:18 PM, Don Phillipson wrote:
The fluorescent lamp on a Kenmore Model 250 stove (now
20 years old) has started wrecking new fluor. tubes
(Sylvania, 22-inch, 18 watts). Symptoms a
1. Dark grey bars appear at both ends of the new tube
within 5 min. use.
2. Tube lights only at the two ends (dark in the middle
for 18 inches.) One end shows white light, the other pink light.

What does this mean?

Starter/ballast gone...

--

On Nov 24, 1:40*pm, Tony Hwang wrote:
Don Phillipson wrote:
The fluorescent lamp on a Kenmore Model 250 stove (now
20 years old) has started wrecking new fluor. tubes
(Sylvania, 22-inch, 18 watts). *Symptoms a
1. *Dark grey bars appear at both ends of the new tube
within 5 min. use.
2. *Tube lights only at the two ends (dark in the middle
for 18 inches.) * One end shows white light, the other pink light.

What does this mean?

Hi,
The tube is worn out.

No - New tubes don't go bad that quickly. Sounds like the starter
contacts are shorted closed and not openiing after a few seconds like
they are supposed to. The warm glow seen by the OP is the heaters
staying on because the starter contacts are staying closed more than a
few seconds. The blackening is due to the filament material being
burned off by the filament staying on. Normally, only a little bit of
material gets burned off each time the light is started. When the
filament stays on ther material gets rapidly burned off and deposits
on the cooler glass where is turns dark. I'd bet a lot of $$ on a
stuck starter.

Don:

I'd phone Sylvania's 1-800 customer service phone number to see if they've had a problem with their small fluorescent range tubes and see what they say. Maybe talk to their tech support people and tell them about the dark grey bands.

Any leakage of oil from the ballast is a sure sign that it's kaput.

Do I read that you put a NEW tube in, which
gets grey ends in a couple minutes of being new?

That's a new one, to me, if so.

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"Don Phillipson" wrote in message
...
The fluorescent lamp on a Kenmore Model 250 stove (now
20 years old) has started wrecking new fluor. tubes
(Sylvania, 22-inch, 18 watts). Symptoms a
1. Dark grey bars appear at both ends of the new tube
within 5 min. use.
2. Tube lights only at the two ends (dark in the middle
for 18 inches.) One end shows white light, the other pink light.

What does this mean?

--
Don Phillipson
Carlsbad Springs
(Ottawa, Canada)

If the tubes grey-end in five minutes, that's my diagnosis also. Starter
stuck.

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"hr(bob) " wrote in message
...

No - New tubes don't go bad that quickly. Sounds like the starter
contacts are shorted closed and not openiing after a few seconds like
they are supposed to. The warm glow seen by the OP is the heaters
staying on because the starter contacts are staying closed more than a
few seconds. The blackening is due to the filament material being
burned off by the filament staying on. Normally, only a little bit of
material gets burned off each time the light is started. When the
filament stays on ther material gets rapidly burned off and deposits
on the cooler glass where is turns dark. I'd bet a lot of $$ on a
stuck starter.

"Don Phillipson" wrote in message ...

The fluorescent lamp on a Kenmore Model 250 stove (now
20 years old) has started wrecking new fluor. tubes
(Sylvania, 22-inch, 18 watts). Symptoms a
1. Dark grey bars appear at both ends of the new tube
within 5 min. use.
2. Tube lights only at the two ends (dark in the middle
for 18 inches.) One end shows white light, the other pink light.

What does this mean?

--
Don Phillipson
Carlsbad Springs
(Ottawa, Canada)

The starter has a capacitor across the contacts that has shorted and acts as
the contacts are stuck. The contacts have a resistive heater in series with
the filaments on the ends of the tubes that will go off when the contacts
open after the tubes glow. That causes the contacts to open in a very short
time when working correctly. Replace the starter when replacing the tubes.
WW

On Nov 24, 7:18*pm, "Don Phillipson" wrote:
The fluorescent lamp on a Kenmore Model 250 stove (now
20 years old) has started wrecking new fluor. tubes
(Sylvania, 22-inch, 18 watts). *Symptoms a
1. *Dark grey bars appear at both ends of the new tube
within 5 min. use.
2. *Tube lights only at the two ends (dark in the middle
for 18 inches.) * One end shows white light, the other pink light.

What does this mean?

--
Don Phillipson
Carlsbad Springs
(Ottawa, Canada)

Something here on the topic of fluorescent tube failure.
http://en.wikipedia.org/wiki/Fluores...ht#End_of_life

On 11/24/2012 1:18 PM, Don Phillipson wrote:
The fluorescent lamp on a Kenmore Model 250 stove (now
20 years old) has started wrecking new fluor. tubes
(Sylvania, 22-inch, 18 watts). Symptoms a
1. Dark grey bars appear at both ends of the new tube
within 5 min. use.
2. Tube lights only at the two ends (dark in the middle
for 18 inches.) One end shows white light, the other pink light.

What does this mean?


If you there is a starter and if it is stuck both ends should be kinda
pink from the filaments. You might evaporate the filament to blacken the
ends.

For ballasts that power the filament, if a filament opens (or bad
contact to ballast) you can get end blackening at that end. The tube
would light, and 5 minutes sounds real fast.

My guess would be starter (if there is one), contacts from ballast wires
to socket and socket to tube, then ballast.

You could try sci.engr.lightning. Some real smart people. It is pretty
dead now, but some of the regulars seem to still be around.