My brand new green laser pointer "603" is not working

Hi ive just bought a brand new green laser pointer from China three days ago and it costs roughly about USD$25 and i have just used it today , i tried placing my previously bought 4.2V Ultrafire Li-ion batteries and no light came out of the laser. But it was working fine before changed the batteries. But however when i put my Ultrafire 3.7V(came with the laser) , the laser suddenly does not work. My surrounding temperature is around 30degrees celsius . May i know if the problem is caused by my batteries or wasi just unlucky to buy a faulty laser? By the way it says 200mW on the sticker, not sure if its real. Would appreciate some advice.

might have blown out the diode if the driver wasnt particularly flexible... i did that with a cheepy green by putting in a higher voltage battery as well

But the 4.2V battery did not really have any power in it , ive left it on the table for quite some time and just decided to try using it. Nothing lit up when i used that battery. Any suggestions on how to fix my laser?

Is it possible you put the batteries in the wrong way? If you reverse the polarity it will wreck a diode. Some drivers can handle reverse polarity, but based on the details you provided I am willing to bet that is not one of them.

Another question: have you dropped it or anything since you got it? Green lasers can be quite delicate due to the intricate crystal alignment that causes the Infrared diode inside to change to the 532nm light that exits the aperture. If the crystals got bumped out of alignment, your laser could be working fine but not doubling the frequency of the photons so all you get is IR light.

Last possibility I can think of, and I hope someone else can shed some more light on this because I don't know much, but IIRC batteries can be unstable when they are almost out of voltage(again...IF I remember correctly). So it is possible that your batteries, being almost out, "over discharged" causing a current spike? Anyway...don't know much about the battery thing, but I seem to remember reading about it somewhere so thought I might mention it.

Hope something in the above rambling is able to assist you,
Isaac

Nope , I definitely have not placed the batteries on the wrong side nor dropped it before . And my batteries are brand new . Still not sure what the problem is .

You probably killed the module, you placed in (If I understand correctly) two 4.2V batteries in your laser, instead of the 3.7V batteries. That equals in a 1V difference between the 2 sets. Since you paid $25 for a 200mW green laser, it's probably under-spec and has a crappy driver that couldn't handle the extra 1V. So if the module is blown there is no way to fix the laser.:cryyy:

Only 1 battery is used for the laser and i dont think my 4.2V batt had any power in it at all.

Still the rule still stands: You can't expect to get a high quality green laser for only 25 bucks! Even if it wasn't the batteries' fault, the laser wouldn't have lasted long

Hmm so how much would a laser that could last for at least a year cost?

How strong laser do you want? The prices vary hugely on the power

What's the cheapest laser that can burn ? Any recommendations on where i can buy from?

As for red lasers you will need 200mW+ to light a match (Which can be done fairly easy with those levels of power), which will cost you about $60 with batteries here: PowerCheck Laser: 650nm Red Focusing Laser 200mW V3 Class 3B laser - Detailed item view - OdicForce Lasers Online Shop

As for a green laser you will need around 150mw+ to light a match. You can get one here with batteries and a charger for around $80: Powercheck Laser: Focusing Shutter-head Green (532nm) Laser with Power Options of 100 - 200mW - Detailed item view - OdicForce Lasers Online Shop. The supplier for both of these are Odicforce which is a good company for buying lasers and associated with lasers situated in the UK.

I have my old CNI 532nm laser from way back in 2006. It all depends on what you want to pay, for what quality, and how you treat the laser.