Please help me troubleshoot an incandescent mag build

I have the following mag build:

Host:
3D mag, quad - bored
FM 12AA - 3D holder (14.4 V, series)
12 x new eneloop AA batteries, 2 cycles on each
resistance mod on the tail cap

Switch:
1) AW softstart
2) stock switch with g4-PR adapter

bulb:
Generic 6V 20W G4 (can be overdriven to 14.8V, tested with 4 Li-ion)

The PROBLEM:
I can't get this light to light-up with the battery holder. I've tried the following power source with both AW and stock switches:

#1: 3AA series holder (4.5V) x 2 + 1 dummy cell

#2: 12 AA - 3D battery holder

Both switches will work with power source #1, but not with power source #2. I also did the paper clip test and the result is the same.

Based on multi-meter reading, the battery holder when loaded, has a voltage of 16+, so I would imagine there is no connection issue with the holder. And since power source #1 works, I think there is no issue with the host.

It seems that the only possible issue is the battery pack is not making connection either with the switch or with the tailcap, but when put together, there is no rattling inside.

I'm quite at a loss to figure out how I can get this thing to light up.

Any suggestions?

Thank you.

horizonseeker said:

Generic 6V 20W G4 (can be overdriven to 14.8V, tested with 4 Li-ion)

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I haven't seen such a bulb yet. Maybe total resistance is too high or batteries are too weak.
However, you can test same bulb with 12AA outside the flashlight to see if battery holder and batteries have good connection.
Again, I am not sure 6 volt bulb can be overdriven with 12 healthy AAs but if you flash the bulb, then try the test with 12V, 35W bulb.

Hi, FM:

I don't mind the bulb flashing, if it does, at least I know the connections are working, right now there is no light.

The bulb will light with 6 AA alkaline batteries in 3AA cheap carriers, using either the AW soft start or stock switch and I've overdriven this same bulb before in a g4 set up with 4 Li-ion so it should handle the 12 AA.

In any case, this bulb can be blown and I have more 12V coming in later from bulbconnection. It just happened to be the one I have on hand for testing.

fivemega said:

However, you can test same bulb with 12AA outside the flashlight to see if battery holder and batteries have good connection.

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Hi, FM:

are you saying I should test the holder outside of the light? do I just connect the positive and negative end of the holder to the pins of the bulb?

I measured 16+ volt using my multimeter on the holder when filled with 12 AA, wouldn't that mean the holder and batteries do have a good connection?

thanks.

PS, bulbs came so tried with a 12V 30W bulb, no light.

Is it possible that the positive end of the 12 aa battery carrier is not making proper contact with the switch? That's about all I can think of since you're able to read a 16+ pack voltage and different battery carriers work fine.

It is possible, although the positive end of the holder is a raised button and shouldn't have trouble contacting the switch, I will try to see if I can stuff some foil in the bottom of the switch as a quick test for connection.

david.

horizonseeker said:

are you saying I should test the holder outside of the light? do I just connect the positive and negative end of the holder to the pins of the bulb?

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Yes, outside of flashlight using jumper wire.

horizonseeker said:

I measured 16+ volt using my multimeter on the holder when filled with 12 AA, wouldn't that mean the holder and batteries do have a good connection?

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Forget about multimeter.
I need to know your pack (batteries and holder) are capable of such a current.

Ok, here to report:

I used the 12 AA battery holder and a cheap (DX) 3AA holder for test, the bulb is a 12V 10W bulb (GE) with wires directly connecting holder to the legs of the bulb.

3AA holder: 3 X Generic Alkaline, 3 X eneloop, both sets will light up the bulb (very yellow, but lit)

12 AA battery holder: 12 x generic alkaline, 12 x eneloop, no light.

Bulb is dead

by "bulb is dead" do you mean

1) bulb is non-functional? this is not the case since it will light up with the 3AA battery packs stacked

2) bulb is incorrectly functioning and only works with lower voltage? this is unlikely as this is the 3rd bulb I've tried and they all behave the same way.

horizonseeker said:

I measured 16+ volt using my multimeter on the holder when filled with 12 AA, wouldn't that mean the holder and batteries do have a good connection?

Click to expand...

horizonseeker said:

12 AA battery holder: 12 x generic alkaline, 12 x eneloop, no light.

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According to above statements, battery holder has loose connection.
Please remove batteries and clean all holder connections. Also clean all negative and positive battery terminals then recharge and retest outside and inside flashlight with good 12V bulb.
It will be helpful if you try following setup inside the flashlight with good 12V bulb.

horizonseeker said:

3AA holder: 3 X Generic Alkaline, 3 X eneloop, both sets will light up the bulb (very yellow, but lit)

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I will try it again after cleaning the contacts one more time.

The bulbs are fresh from bulbconnections. I'll try 3 different types and report back.

I have tried that set up from the beginning, but with 2 of the 3XAA pack + a dummy cell (it's what I have on hand), that will light up the bulb, just never with the battery holder.

THANK YOU EVERYONE!

I got it to work!

Found out the problem when I decided that a regular cleaning is not going to work since I've done that already. I took the entire thing apart and got out my sandpaper to polish everything. During the process I found that I missed one section in the previous cleaning process, the center of the battery holder where the center rod screws in, there is a brass contact underneath the strip that I didn't clean out enough. So I polished that and all the brass contacts I could get apart with sandpaper to make sure it will have a clean contact.

Sure enough, once I sanded it down to a shiny surface, it is now working with the 12 eneloops I put into it.

Glad to hear you sorted it out! Happy paper burning to you!