[rv31rv]

I have an undercabinet fluorescent lamp fixture that suddenly quit
working. After verifying the tube works in another fixture & pulling
the board out of the housing, I checked all components & they seem to
be OK except for a component that looks like a black diode without a
band. It appears to be open & has DB3 printed on it & the PCB next to
it. I looked on line & have not been able to find the PCB name for a
"DB" device. Any help? Thanx.

[James Sweet]

rv31rv wrote:
I have an undercabinet fluorescent lamp fixture that suddenly quit
working. After verifying the tube works in another fixture & pulling
the board out of the housing, I checked all components & they seem to
be OK except for a component that looks like a black diode without a
band. It appears to be open & has DB3 printed on it & the PCB next to
it. I looked on line & have not been able to find the PCB name for a
"DB" device. Any help? Thanx.



Not sure what that is, but if all else fails you can probably pull the
ballast circuit out of a cheap CFL.

[rv31rv]

On Feb 10, 11:05 am, "rv31rv" wrote:
I have an undercabinet fluorescent lamp fixture that suddenly quit
working. After verifying the tube works in another fixture & pulling
the board out of the housing, I checked all components & they seem to
be OK except for a component that looks like a black diode without a
band. It appears to be open & has DB3 printed on it & the PCB next to
it. I looked on line & have not been able to find the PCB name for a
"DB" device. Any help? Thanx.

Found it. It's a Diac, which fires the scr.

[Jamie]

rv31rv wrote:

On Feb 10, 11:05 am, "rv31rv" wrote:

I have an undercabinet fluorescent lamp fixture that suddenly quit
working. After verifying the tube works in another fixture & pulling
the board out of the housing, I checked all components & they seem to
be OK except for a component that looks like a black diode without a
band. It appears to be open & has DB3 printed on it & the PCB next to
it. I looked on line & have not been able to find the PCB name for a
"DB" device. Any help? Thanx.


Found it. It's a Diac, which fires the scr.

which does not mean it's bad just because your meter
said it's open.
you need to apply the level of voltage required to
switch it on.


--
"I'm never wrong, once i thought i was, but was mistaken"
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5

[Homer J Simpson]

"rv31rv" wrote in message
ups.com...

Found it. It's a Diac, which fires the scr.

It takes about 32 V to switch on.

[W. Curtiss Priest]

Prior to the electronic "ballasts" and prior to designs that
were "self-starting" -- there are typically only 2 parts --
the ballast transformer and the "starter"

So, we presume this item is the starter. Such starters
were originally in aluminum cans and had two prongs for
replacement.

If this is the starter, get a starter from a hardware store for
the same wattage flourescent lamp.

Presumably, if you just solder that starter in place, it should work.

Or, you might let some smoke out of something.

Curtiss
"rv31rv" wrote in message
oups.com...
I have an undercabinet fluorescent lamp fixture that suddenly quit
working. After verifying the tube works in another fixture & pulling
the board out of the housing, I checked all components & they seem to
be OK except for a component that looks like a black diode without a
band. It appears to be open & has DB3 printed on it & the PCB next to
it. I looked on line & have not been able to find the PCB name for a
"DB" device. Any help? Thanx.

[Eeyore]

rv31rv wrote:

On Feb 10, 11:05 am, "rv31rv" wrote:
I have an undercabinet fluorescent lamp fixture that suddenly quit
working. After verifying the tube works in another fixture & pulling
the board out of the housing, I checked all components & they seem to
be OK except for a component that looks like a black diode without a
band. It appears to be open & has DB3 printed on it & the PCB next to
it. I looked on line & have not been able to find the PCB name for a
"DB" device. Any help? Thanx.

Found it. It's a Diac, which fires the scr.

That makes sense. DB = diode (breakdown).

Graham

[James Sweet]

W. Curtiss Priest wrote:
Prior to the electronic "ballasts" and prior to designs that
were "self-starting" -- there are typically only 2 parts --
the ballast transformer and the "starter"

So, we presume this item is the starter. Such starters
were originally in aluminum cans and had two prongs for
replacement.

If this is the starter, get a starter from a hardware store for
the same wattage flourescent lamp.

Presumably, if you just solder that starter in place, it should work.

Or, you might let some smoke out of something.



This is obviously a newer electronic ballast rather than the old choke
and starter arrangement. Reliable as that is, it's not seen as often
anymore.

[Franc Zabkar]

On 10 Feb 2007 08:05:58 -0800, "rv31rv" put finger
to keyboard and composed:

I have an undercabinet fluorescent lamp fixture that suddenly quit
working. After verifying the tube works in another fixture & pulling
the board out of the housing, I checked all components & they seem to
be OK except for a component that looks like a black diode without a
band. It appears to be open & has DB3 printed on it & the PCB next to
it.

It crosses to an NTE6408 "bilateral trigger diode", ie a DIAC. As
already mentioned, the breakover voltage is 32V.

See http://www.nteinc.com/specs/6400to6499/pdf/nte6407.pdf

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.