My laser is broken :'(

[dpetrillo]

I bought a RGB1500 (R:300/638,G:200/532,B1000/445) from Golden Star in July of last year. I have used it for maybe 25 hours total. I noticed the last time I used it that green was not showing up correctly at first, but after about 15 minutes it warmed up and looked normal. Now green is so faint it's barely visible and does not change over time.

I don't have any DAC or software, and just use this on random mode with a $25 fog machine in my apartment when I throw parties.

I emailed Mimi who said:

"I think it is normal problem for 532 DPSS green, not only you have such problem, but also other customers also meet problem with 523 green." and confusingly offered to sell me 5W 520nm green for $1500.

If my chances of getting it repaired by golden star are out the window, I'm going to troubleshoot this myself. I am comfortable with the idea of opening it up, checking voltages with a multimeter or a scope, replacing stuff and then learning how to adjust everything so it works properly again.

My question is.. where do I start? This is my first time working on a scanner, and I am not very familiar with them. If there is a book, or a collection of things I could read, let me know. I looked around the form for similar stuff, but I have to admit, I didn't do it exhaustively. As a starter I think I would check to see if I can determine if it is getting the correct power from the supply to see if it is the laser or the supply. The problem is I don't have a way to check the laser easily without a DAC, so I guess I will have to buy a starter DAC and software package in order to do this.

Any suggestions are greatly appreciated.

[norty303]

Be aware that DPSS lasers are fickle beasts. They are complex technology to the uninformed and require a few things to be correct in order to function effectively. Temps, and alignment predominantly.
This is confounded by the fact the pump diode that needs aligning is an infrared wavelength and hazardous to eyes even though invisible means you need to go into this in an informed way.

The common reasons for low power on DPSS are misalignment of the primary lens meaning the IR beam onto the crystal isn't correctly focussed or on target, the temp of the SHG not being optimal or the crystal itself having deterioriated due to moisture ingress, as they are hygroscopic.

I have successfully realigned a couple of my DPSS heads, but i've also killed a diode completely due to shorting it in the alignment process. I made sure i had IR goggles for when i ran the laser with the case open.

https://en.wikipedia.org/wiki/Diode-...id-state_laser

If i was in your position i would find someone on the forum who could build you a simple 700mW 520 module and switch it out.

For testing your laser without a DAC i can thoroughly recommend the ILDA Gem from Rob Stanley (Stanwax Laser)

[Bradfo69]

While 532 DPSS was the standard for green for a long time, most have moved on to the 520 diode based green, in part due to what you are describing. Generally most I think tend to have been pretty solid, since they've been used in everything for years but, one common problem has been the gradual dimming over time. The problems with DPSS just don't happen with diode so, many, including most manufactures have made the switch over to 520. It's also usually something internal with the module and often not an easy or safe fix without the proper tools, knowledge and safety considerations. A lot of what comes out of that laser is power you can't visibly see so, popping the cover and playing around with alignments can be a dangerous thing.
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The issue you may find is getting a replacement at 200mW. Yes, I assume there are still companies making them but even a search of Goldenstar's site brings up 520 diode modules starting at 1 watt. It may be something you have to look for second hand. The green diodes themselves start at 700mW. You can get a single mode 520 green diode in much lower power that may be a good match to your green and blue but, I don't know anyone selling just a 200mW or comparable 520 module. Maybe a search of eBay is in order. I have no idea why they would have tried to suggest a 5 WATT green! That's kinda crazy.
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Swapping out a module in theory shouldn't be hard but, there are a lot of things that come into play and you'll want something roughly the same size, and beam height to put back in your projector. Biggest thing I can suggest it letting us know where in the world you are from to see if there is someone close that can help you with this.
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(Norty got his reply posted while I was working on mine and it's a bit more descriptive but, you would be getting into very unsafe territory trying to actually get into the thing and realign the inside. Best to just find a whole 532 replacement or, as was suggested switch to 520.)

[dpetrillo]

Thank you very much for the fast and insightful replies. The ILDA Gem looks like the perfect tool. Troubleshooting the module sounds like a large undertaking.

If the module itself is just swapped with another identical one, knowing full well that they aren't very reliable, would it be very dangerous or difficult to swap and align it to the other lasers and scanners? I am prepared to really dedicate some time to understanding how to do that correctly.

I figure I could probably convince Golden Star to send me an identical replacement module for a reasonable fee. I don't want to spend more than the price of the original laser to just swap to a similar power 520 green just yet.

[Bradfo69]

Swapping an identical module out should be fairly simple and just take an allen wrench and maybe a screwdriver and a few minutes of your time. Same with alignment. That's usually takes just a few minutes too and is basic maintenance every laser owner ought to become familiar with at least how to do.

[norty303]

A 200mw 532 module should be very cheap these days.

[planters]

dpetrillo,

You should go ahead and tell us where you are. This is an honest request and there really might be someone close by that can help you. This does not mean you have to meet, but it can save a lot in shipping and the recommendations you get for suppliers may depend on where you are.

That being said and although you must be frustrated that a "turn key" projector is turning out not to be, you might discover that repairing this projector can be interesting and even fun.

Blow off Mimi.

Open up the projector and look at the name of the manufacturer of the green module. Goldenstar does not make laser modules, at least they didn't a couple of years ago. They assemble projectors from lasers and scanners and power supplies, made by other manufacturers. Laserwave was one of their green DPSS suppliers in the past.

See if you can operate the projector with the cover off. Confirm that the green is actually dim and not simply grossly misaligned. If you can identify the manufacturer then you might find that they will sell you a replacement laser for MUCH LESS than $1,500. Don't even attempt to repair a DPSS laser. Unless it is over 2W it is not worth the steep learning curve and the kit you will need to do a repair that could be due to any of a number of system failures.

Your power requirements are so low that a direct green diode is a viable alternative, but it would mean a little more complicated swap out due to module height and the need to provide a compatible power source. These direct diodes are not necessarily an upgrade. The beam quality from a good DPSS is very good and some users prefer the slightly red shifted color of 532nm when mixed with the blue and the red. Some users do not. The direct diodes are more reliable, but most DPSS lasers should run for thousands of hours.

[dpetrillo]

Planters - I totally forgot to mention that I live in New York City, Chinatown to be exact. If anyone wants to meet up I would be more than happy to do that. I went to SELEM 2015 and had a great time and would go again if this became more of an important hobby for me.

Also thank you for your advice, I will definitely open it up and take a look to see what I can find. I think I know what I need to do now.

[VJ AIWAZ]

I could take a quick look i need to go to cielo one day this week to return their lasers (just not sure what day I'm waiting on them cutting a check )

--
Thanks
John Loughlin
Technological Artisans
http://taiserver.com
(347)606-1076

[Bradfo69]

I know there are some members close by that could assist you if you want any help. HankLloydRight is just into CT a little bit although he's a bit busy this month, getting all like married and stuff.