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Another broken laser - HeNe 612nm. Tube lights fine.. but

Joined
Nov 17, 2009
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So, I received a Melles Griot 05-SOR-851 612nm HeNe laser today. Seller claimed, of course, that it worked fine, "no damages."

Well, try to start it up -- with the internal Melles Griot PS - nothing.

Tried wiring in my Melles Griot PS of the *exact same model internally* (the 'brick' is the same)

and the tube lights, the gas color looks fine but... No beam.

Any ideas?
 





Yeah, thats why I jumped at the chance... Any idea what could be up with the tube, if it does light fine but doesn't lase?

The PS that came with it was certainly dead, I was hoping the tube would be OK... Could improper grounding or anything keep it from lasing?
 
If the gas discharge looks good, it must be out of alignment. I'm not a gas laser expert, but HeNes are pretty simple.. If the gas glows and the mirrors are right, it should lase. Sealed mirrors are very hard to realign.
 
I've never seen the insides of that model HeNe, does the cover come off easily? Are the mirrors attached directly to the tube? If so, it will be more difficult to re-align, but it can be done. The only other thing I can think of is the current. When you attached your supply, do you have still have the ballast resistors attached? I've heard, though I've never seen this, that too much current can actually cause them not to produce a beam.
 
I know people have said you can sometimes bend them back into alignment... but with it being sealed, Id ont know. Maybe this happened in shipping. (likely.)

Some images of it...
 

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I am keeping the ballast resistor in line yeah. I can try a lower powered supply, but this is the same supply that came with the thing (external with the same 'brick' this had in it)

Just tried two other power supplies; a 5.0mA, 6.0mA and a 6.5mA one. I know on the PS that came with it there was a "Calibrated Current Output" sticker over a little knob, basically saying "don't turn this". I suppose the externals I have could be too high (but even at 5.0 ma?)
 
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Both supplies are spec'd to put out the same current? If that's the case, then it's most likely an alignment issue. You gotta be real careful trying to re-align them, and know that the tube itself acts like a big capacitor, even with the supply removed, the thing can nail ya, don't ask me how I know! I've used the plastic middle part of a highlighter to flex the ends of tubes like that before. If it's off, I doubt it's by much, just a little flexing of the one side, then the other and you might get lucky.

Just speculating, but lowered gas pressure may be at fault.??

Tube pressure could certainly be an issue, I'm going by the assumption that it worked prior to shipping.
 
Tube pressure could certainly be an issue, I'm going by the assumption that it worked prior to shipping.


That's giving the ebay seller too much credit...unless they are a known laser seller with 100% feedback, then I am sorry I said that, but in my experience, unless the guarantee NO DOA, I lack the faith to trust them.
 
The guy wasn't a laser guy, but claimed it was "Great condition, well preserved, no damages." I'll try flexing the ends (barely) with a highlighter and see what happens; but i'm not getting my hopes up.

EDIT: Flexing of the ends, no change, no go, nothing.

I am betting that this is as close as I'll *ever* get to a 612nm laser.
 
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Dayum Dood!

You are getting hella used gas laser education hella fast.

With the construction of that housing, you can see that it would be darned near impossible to knock the mirrors out of alignment without damaging the glass. All of the support is on the glass tube, NOT the metal ends.

Since you have it opened, certainly try wiggling stuff around (not too vigorously). If you get it to lase, SWEET! However, I highly doubt that it was lasing when the seller packaged it up.

The plasma color looks good (although the camera often alters subtle color variations). If you are getting a solid plasma (without "clicks" or a "buzz" from the PSU) the PSU is working. Either the gas mixture is bad or the mirrors are out of alignment.

The former you cannot fix. The latter is VERY difficult to fix.

Peace,
dave
 
Or the seller is a scammer, drop the seller a line, ask for a refund and see what happens.

If the seller refuses to refund, the seller is a scammer.

I got a broken hene not too long ago, the seller reversed the paypal and told me to keep it.

I gave him a A+ feedback. Integrity is everything.
 
Dayum Dood!

You are getting hella used gas laser education hella fast.

Sure am, Dave! Definitely this got my hopes down though. My kind of "can die happy" laser was a 612nm, and since I bought it a week ago I've been pacing around waiting for it to come... Sweating the moment I tried to turn it on..

And.. nothing. Of course. (my luck.)

No cracks in the tube and i've looked all over to make sure. It hasn't broken free from its mounting.

There are no clicks from the PS. It's lighting solidly. The gas mix, from what I can tell, looks good. Red-orange-pink, not pink-purple.

Just no beam.

I hate feeling so close but yet so far. And it wouldn't surprise me if this was the last 612nm laser "floating around" *anywhere*.
 
Talk to the Seller fists....
Did the eBay Listing state that the laser lases and.or is guaranteed.
Or did he state AS IS...
If you believe you've been duped... open a PayPal Dispute and escalate it
to a claim if the seller is not helpful or cooperative..

BTW... from the plasma in the capillary tube it looks like the mirrors are
out of alignment...IMO


Jerry
 
He did not state 'as is'. He stated, "Well preserved, no damages." However, the seller has not been communicative so far , early on when I asked him right out if it worked or not.

As far as the plasma goes - you can tell the mirrors are out of alignment by that?
 
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