Galvo Help with X-Laser Mobile Beat RGB MKVs

[Braindead3xl]

Hi, I have three of these great little class 3b lasers. I really love them in spite of them only having 15k scanners. Their beams are super tight, and for a cheap TTL laser, the color from these (especially the whites) is pretty impressive. But all three of them seem to be exhibiting the same issue from time to time. Maybe someone here can help.

They were all manufactured in the summers of 2013 and 2014. So they're getting some age on them. All three of them from time to time will have the horizontal width of their projected images go wacky. After a few minutes, it usually clears up. And it seems to only be relating to the X axis, not the Y.

Here's a poorly shot iphone video. The flicker is severe because of the phone's shutter speed, but you can get the idea. As you can see, the yellow heart has a jittery width.

https://drive.google.com/file/d/1cJy...ew?usp=sharing

I was guessing that maybe it's something related to aging caps in either the power supply or maybe the driver boards. But if that's the case, why isn't the vertical galvo affected as well? Since the X and Y galvos are identical, it doesn't seem to point to a galvo failure since A: it clears up over time (usually, not always), and B: all three are exhibiting the same problem, only on the X axis.

What would be super cool is if I could hire a repair shop to replace the scanners with new 30k scanners. That'd be amazing. But short of that, I'd love to just get these back to their original working state.

Any suggestions of where I might start looking?

Thank you.

[buffo]

Have you tried reaching out to X-Laser to see what they think? I don't know what it would cost to repair your units, but if the repair cost ends up being cost-prohibitive, you might ask them if they'd be willing to sell you a set of replacement scanners - assuming you'd be comfortable swapping them out yourself, that is. Then too, they might be able to suggest some other repair that you could try yourself first.

Another option would be to simply purchase a cheap set of 30K Chinese scanners and install them in place of the original scanners. However, I'm pretty sure the scanner amps in all of the Mirage projectors run off just +/- 12VDC, instead of the +/- 24 VDC supply that most other scanner systems use. Installing a new +/- 24VDC PSU inside a Mirage projector would be a real challenge due to the limited space inside.

I agree that the beam quality on a Mirage projector is very good. (I own 3 of them myself.) That tight beam makes the Mirage projectors appear much brighter than they really are, and it also makes them an ideal projector for graphics and complex abstracts. That's a solid reason to invest a little money to keep them going, I think.

Adam

[Braindead3xl]

Great input. That's good to know about the voltage of the scanners. I've never opened up a laser projector before, so I'm rather intimidated by the idea. But like you mention, I like these little boxes so much, I'm willing to give it a shot. I'm sure I can handle a few basics. Hopefully I won't get in over my head if I have to repair it myself.

I dropped X-Laser support a line asking if they'd repair a box that's so old. If they say no, then I may just go the Chinese galvo route. If I need to add a 24v secondary wall-wart power supply just for those Chinese galvos, then so be it. Could be a fun project.

Thank you.

[buffo]

I think you'll find that working on the internals of a laser projector is not nearly as difficult of a task as it might seem. Honestly, in my experience, the hardest part is often related to things like adjusting the mounting heights of components, rather than any electrical concerns.

I do need to address a serious mistake that I made with my post above, however: upon further reflection, I'm certain that X-Laser will not be able to send you a set of replacement scanners, no matter how much they might cost. The reason is that according to the CDRH, you, as the consumer, are not allowed to perform "service" on the projector; that can only be done by a laser product manufacturer, since once the case is re-sealed with the new components installed, the projector must be re-certified, and you don't have a laser product manufacturer's variance.

Now, you could still open the case yourself and install whatever scanners you want, but when you're done, technically the projector will no longer be a certified projector. If you're just using them for your own amusement in the privacy of your own home, then that's not a problem. But if you ever wanted to use them for a public show, then they would not be considered compliant anymore.

I also missed that you were talking about the original Mobile Beat RGB projectors, and not the newer Mobile Beat Mirage units. I think those older Mobile Beat projectors did in fact come with 15K scanners, but I think they also used a +/- 15VDC power supply, which might make it easier for you to find a modern replacement set. (I've seen lots of modern 20K scanners on Ebay that use +/- 15VDC supplies, for example.)

Also, because we're talking about these older projectors, it's very possible that X-Laser no longer has parts available for these units. So even if you were willing to send the projector to them for repair, they might not be able to repair it.

Note that the power supplies we're talking about for the scanners are dual-rail supplies - that is, they supply both a positive voltage and a negative voltage. So a +/- 15VDC power supply has three terminals on the output: +15 Volts, Ground, and -15 Volts. So that's a bit more complicated than a simple wall-wart PSU.

[Braindead3xl]

More great info like I've come to expect from photonlexicon experts! Thank you!

I actually heard back from X-Laser, and they confirmed that they can no longer get parts for the RGB MKV manufactured so long ago. Bummer. So, I'm about to take the sticker off (OH NO! It says it'll void my warranty if I do!) ... And let's see what's inside this little thing.

Great point about the laser no longer being compliant. I do have variances for them, and I had planned on using them in public shows, so this is something I'll need to consider a bit.

Thank you. I may come back around to this thread looking for help on installing / aligning new galvos. I just cracked open one of them and you're right, it seems pretty straightforward. It was easy to pull them out.

It looks like this is *almost* an exact drop-in. A lot of the parts look very similar to mine. Maybe this kit will get me going again? https://www.ebay.com/itm/385681484143

[dazebtwn]

"They were all manufactured in the summers of 2013 and 2014. So they're getting some age on them. All three of them from time to time will have the horizontal width of their projected images go wacky. After a few minutes, it usually clears up. And it seems to only be relating to the X axis, not the Y."

Just read through your posts...

If you are using the internaly generated graphics and the video shows all three projectors with just one failing then, perhaps...

It could be that the "pattern size" potentiometer on the rear of the units have developed an intermittent connection to the wiper for the x axis. I noticed that in some photos of these projectors they have seperate x and y size adjustments whereas the MKV are combined eg. stacked. Could just be that the x fails first. Your recent images shows the pot with a hole in the center so it is not even close to being sealed and that style pot may not age gracefully. Do you always have this pot fully clockwize on all units? Before you remove the galvo's you may want to try moving that pot to a different location and see if the problem still exists. The fact that all three projectors exhibit the same anomaly seems to point to an intermittent issue. My analog console will do the exact same thing on a few pots that are tempermental. Usually just moving the pot back and forth a couple times will clear the issue. If it is indeed the pattern size pots you could attempt to clean them with Deoxit or just replace them. Try scaling back the image size and see if it stablizes.

[Braindead3xl]

If you are using the internaly generated graphics and the video shows all three projectors with just one failing then, perhaps...

i use them exclusively with the ILDA inputs using Beyond.

That's a good point about the pots, though. A thought I hadn't considered. They have a big external pot on the back to adjust the overall beam size, and that is dirty on all three of them (and one is flat out toast - any adjustment at all turns the image to a single hot beam - although that's easy to replace).

So, are you suggesting that I apply some deoxit to the little gold pots on the driver boards, and work them back and forth a bit? They certainly are behaving like a flaky pot would now that you mention it. Sometimes fine, sometime glitchy.

You'll have to forgive me. I'm not sure what I'm looking at here. There appears to be separate X and Y control boards feeding into the galvos. Each board has 6 tiny gold pots on the boards housed in a blue plastic cube. I don't know what those do. Are these the ones I should attempt to clean?

[dazebtwn]

No, absolutly not with regards to the driver boards pots - and do not turn them. Sorry for the confusion.

I was only referencing the big external pot on the back. If that pot is dirty it could be causing your x axis fluctuations. You have now indicated that the external pots are dirty, do you see image distortion when you move them?

[Braindead3xl]

Yes, those external pots (well, the one that exists) is jittery when I turn it, but that affects both the X and Y axis. If I don't touch the beam size pot at all, it's OK. The issue really is with the X axis on all three of them. Very strange.

As a side note, do you happen to know what those little gold and blue pot adjustments on the driver boards do? The idea that perhaps one or more of those are flaky, and giving them a clean (attempting to mark and save their settings) would be a bad idea? I mean, it's kind of already broken anyway. Perhaps I am still looking at that ebay link posted earlier. It looks like a full "gut swap" kit for everything but the beams themselves.

Thank you again for your input. I'm learning as I go.

[dazebtwn]

Yes, those external pots (well, the one that exists) is jittery when I turn it, but that affects both the X and Y axis. If I don't touch the beam size pot at all, it's OK. The issue really is with the X axis on all three of them. Very strange.

1st question: If you disconnect the ILDA cable and run the internal images, do you still have the same X axis issues on all three projectors?
2nd question: Since you are using Beyond, and assuming and FB3 or FB4 DAC, how are you daisy chaining the 3 projectors as there are no ILDA out connectors?

As a side note, do you happen to know what those little gold and blue pot adjustments on the driver boards do? The idea that perhaps one or more of those are flaky, and giving them a clean (attempting to mark and save their settings) would be a bad idea? I mean, it's kind of already broken anyway. Perhaps I am still looking at that ebay link posted earlier. It looks like a full "gut swap" kit for everything but the beams themselves.

Yes I know what the little gold and blue pot adjustments do and that is exactly why I am saying DO NOT TOUCH THEM! Now if you are dead set on replacing the scanners that is always an option, except for all the reasons Buffo explained above, however I do not think that will solve your x axis jitter issue.