CMG Infinity-Problem

Hi! I have a CMG Infinity, and it doesn't work. I've tried various batteries and it just won't turn on. Anybody else have this problem? Thank you!

There were several infinity models, the earliest ones suffering from flakiness due to the roll crimp around the PCB. Anyway, first thing to do is clean the contacts. If that doesn't help, then try punching down the roll crimp with a screwdriver. Use the search function to find some old threads with photos about how to do this.

My CMG died on me long ago, back when it was still the only light I had. I think it would flicker about every fifth time I tried to get it to activate and maybe, for a time at least, could be made to stay on with enough persistence. I searched around and found the PCB issue paulr mentioned, tried the screwdriver and hammer fix for it (gently), and got no improvement. In the end, I think I got it working again when I cleaned the negative contact with a clean pencil eraser and maybe a little sand paper. And, not surprisingly, it's still going strong today. So definitely try cleaning up the contacts, it would have been the first thing I tried if I'd been a little more experienced at the time. Hope your problem is as easy to fix as mine ended up being, these are still great little lights that get a lot of respect.

Mine is comming up on it's 10 year anniversary! hate to hear your's has a problem. I bet it need a little TLC.

Yup, other than gunky contacts (threads on the head, on the body, the (+) contact on the head, and the (-) nub inside the battery tube) there's little else that can go wrong with the Infinity lights.

Unless... you have one of the earliest versions with the reversed polarity battery tube and a metal contact on the head for the (-) contact. Those were unpotted, and a couple of things can go wrong with them.

greenLED said:

Yup, other than gunky contacts (threads on the head, on the body, the (+) contact on the head, and the (-) nub inside the battery tube) there's little else that can go wrong with the Infinity lights.

Unless... you have one of the earliest versions with the reversed polarity battery tube and a metal contact on the head for the (-) contact. Those were unpotted, and a couple of things can go wrong with them.

Click to expand...

I was just thinking this as I read the post. The black bodied RED CMG I have is reversed polarity, AA goes in upside down.

Oh right, those reversed ones were even earlier, I forgot about those. I don't know if they used a roll crimp. Anyway, cleaning the contacts is always the first thing to try.

Paul, IIRC, they were the very first iteration. The details of the build are fuzzy in my head, but I do remember the board being unpotted, and I broke the metal contact thingy on a couple of those.

Even so, I regret getting rid of the ones I had. Big CMG Infinity fan here.

Another vote for thoroughly cleaning all contacts before trying other fixes. I usually clean mine with some rubbing alcohol and Q-tips. Also, make sure the battery ends themselves are clean. If you only clean the contacts on the light and not the battery as well, you're only doing half the job.

I'm glad I have 4 or 5 CMG Infinity Ultra's. They are great lights to have when camping. I put one on a lanyard around my neck. They run for a very long time, and can use cells that won't light up other flashlights anymore. An all-time favorite of mine.

I think Gerber really mucked things up when they changed the Infinity Ultra. They should have left well enough alone. It seems that things like that happen whenever a small company (like CMG) gets bought out by a larger company (like Gerber).

I think I may have the older version...The back of the head has a metal contact, and looks different than some I've seen in pictures online. I think that the battery goes in + down, and I may have put it in wrong. Will this viod the warranty? It is old, almost ten years I think! Dug it out of the drawer and want to put it on my keychain.

http://www.putfile.com/pic.php?img=7459086 <This picture shows the inside of the body, with corrosion which looks like it is from the + end of a AA battery.... I may have put the battery in wrong

http://www.putfile.com/pic.php?img=7459085 <Picture showing reverse side of head, with metal battery contact and my failed repair using screwdriver and hammer method.

Yeah that's the old version where the cell goes + end down into the tube. Try carefully examining the pc board for cracks in the traces. I think they had some problems with the board flexing and that's why they went to the new design. Putting the battery in the wrong way shouldn't bother it other than preventing the light from turning on until you put the battery in the right way. If you contact Gerber for a warranty repair the most likely outcome is you'll get a new Ultra model which is a different design, better than the old Infinity in some ways, but less solidly built and less popular here. If you really want another Infinity, PM me and I'll figure something out for you.

I appreciate your response. I examined the circuit board with a magnifying glass and is appears to be free of any cracks.

In terms of Infinity Ultra vs Infinity, I don't think I'll mind the newer version...the Infinity feels EXTREMELY durable, but I think that I should be fine with the Ultra version. Just one quick question: Does the Infinity have a more focused beam than the Infinity Ultra? I got that idea from here: http://www.flashlightreviews.com/reviews_index/reviews_index_ledsingle.htm

I would prefer focus over flood, but I don't think it matters so much. Thank you again!

Oh, and a quick question about contacting the company regarding the warranty...is this the address I should ship the defective light to:
http://www.vicomptel.com/CMG/warranty.htm

If not, I'd appreciate the appropriate address. Thank you in advance.

I would not send it anywhere but to a CPF member!
You may get back a new gerber :thumbsdow
Let one of our own fix it up and get it going! A classic hard worker like that deserves a good repair or even a mod! Think about it before you give it up to who knows what.

Wow, Vicomptel, a name i haven't heard in a while (dealer who got out of the flashlight biz a while back, I think). CMG is long since shut down (absorbed into gerber). I'd call Gerber on the phone and discuss the situation:

http://www.gerbergear.com/contact.php

When you say "ultra version" you have to understand there are TWO ultra versions that are relevant here: the CMG version (that was also, confusingly, sold under the Gerber label for a short while):

http://www.flashlightreviews.com/reviews/cmg_infinity_ultra.htm

and the current, all-Gerber version which is a completely new design:

http://www.flashlightreviews.com/reviews/gerber_infinityultra.htm

The CMG version is basically a slightly updated revision of your Infinity, with the power level cranked up so that it's about 2x as bright as before, though the battery won't last as long. The metal parts are just about exactly the same (the very oldest Infinities, of which you might have one, had a matte finish that was less durable). It was discontinued a couple years ago though you can occasionally find them if you keep your eyes open.

The new Gerber version is a completely different design where you twist the tail rather than the head to turn the light on. It does not feel as solid as the old version (stamped rather than machined, etc). Conventional wisdom here on CPF is that Gerber messed up a good thing (the new version must cost less to manufacture) and the new version is less durable. Separately from durability though, it will be brighter than any of the CMG versions just because it uses newer LED technology. The old version is sought after and the new version is not very popular. Beam patterns will be about the same for all three of these lights.

So, the concern that people are expressing is that if you send your old Infinity to Gerber, you might end up with the redesigned Ultra which is less of a classic light.

I have three of those old ones and they all work fine. Love 'em.

Wasn't there something about a spot of soldering that wore away or got flattened? You just had to put on a new dab of solder...or was that the old Arc AAA?

Ive had problems with perfectly infinity lights. I put a small piece of aluminum foil under the (-) side of battery. That has helped.

Scott, that'd be the ArcAAA.

e2x2e said:

http://www.putfile.com/pic.php?img=7459086 <This picture shows the inside of the body, with corrosion which looks like it is from the + end of a AA battery.... I may have put the battery in wrong

http://www.putfile.com/pic.php?img=7459085 <Picture showing reverse side of head, with metal battery contact and my failed repair using screwdriver and hammer method.

Click to expand...

Use some fine-grit sand paper and the alcohol to clean the contacts. Rubbing the contact with a pencil eraser (and cleaning the eraser as you go) works well if you don't have sandpaper.

As far as the crimp goes, hit it again between where you reseated the crimp. I can see from the pics the roll crimp is still raised. Don't be shy - TWAK IT! - don't just tap the darned thing. Try to hit it closer to the edge of the head and bring the roll down inwards.


You know, my original Infinities had different metal tabs on the head; they had a (-) sign cut into them.

scott said:

I have three of those old ones and they all work fine. Love 'em.

Wasn't there something about a spot of soldering that wore away or got flattened? You just had to put on a new dab of solder...or was that the old Arc AAA?

Click to expand...

That's the Arc AAA.