Changing of Galvo

[kamakajee]

Hello All,
I'm using a 2.5 watt RGB laser projector purchased from Europe. Now it seems one of the galvo mirror is not working as I get a straight horizontal output line. It is pretty expensive to send the projector back & forth to the manufacture.
My concern how do I repair/replace the galvo?
Can I change the galvo at my end or is it a MUST to send the projector back to the manufacture.
Do I have to change both the galvo's
How do I know what type of galvo to order (any physical mark on the part),
Any precaution be taken to make these last longer (this is the 2nd time within a year that these galvos have gone off).
All the help is appreciated
Thanks Kama

[kitatit]

Hi Kama,
I'm not very experienced with fault finding scanner problems yet but I have no doubt you will find some excellent help here with this matter.

It could be a lost signal connection or as you suspect a failed scanner.

The scanners usually are tuned at the factory/supplier and the amp for each channel is tuned to that scanner.

After the more experienced guys join in on this thread and help you find the problem, shoud you need a replacement scanner and amp it is not too difficult to fit the new parts yourself.

Coming from Europe I'm sure there will be someone who is familiar with the projector you have.

To help them point you in the right direction can you give some more specific info.

-what make and model is it?
- take some good photos of the scanners and the scanner amps and write down any part numbers you can see.
- it's often hard to tell what make the scanners are as many look the same and have few marking. The scanner amps might give their identity away.

It is possible you are driving them beyond their capabilities. Are you doing complex graphics?

It may be worth upgrading the scanners if it's a recurring problem.

Good luck
kit

[Bradfo69]

Horizontal line? That sounds like the Y galvo. (I had a similar problem but mine was vertical and it was the X - supposedly the X works harder.) I got lucky in that it was a simple swap of the motor itself AND I was lucky enough to have someone with one that matched up without needing retuning.

When mine occurred, the story from everyone was doom and gloom but, I got very lucky. If you're able to acertain the manufacturer, you might get lucky as well but, it may be a complete replacement. Scanners and amps are tuned together so, you may be looking at replacing the set. Mine was either a case of overdriving or, it was just their time. I tend to think it was a little of both as I'd only had it 18 minutes before the motor died but, they were secondhand.

Before shipping back the whole projector, I'd definately suggest looking for a member here that's in your area and may be able to offer assistance.

[kamakajee]

It is a Medialas Mystiqe projector, does the galvo come in pair or I can order just the single damaged unit? & is it a must to get the AMP along?
Thanks for all the help.
Kama

[LaserCo]

catweasel comes to my foggy old mind! (and a name like Greg Malkov)

crossing my fingers for you, check here ::
http://www.laserist.org/Laserist/Tech_focus_p4.html

good luck

[andyf97]

Often scanners are fitted with a small fuse, check the fuse first as it could just be that. If the fuse is blown likely you are driving the scanners too fast than they can handle.

What acanners are they or more, what laser is it.

[Lasermad]

K
I have swapped out galvos and kept same amps and its been fine but it depends to an extent on your usage and how much of a perfectionist you are and to a certain extent how expensive the galvos are in the first place.

if just using for beams you might not notice any mis-tuning
if yousing for graphics or TEXT a lot mistunings would likely be more noticible and annoying
if expensive galvos , its likely worth ivesting in correctly tuned amps

Please note when i have swapped without changing amps the complete set of amps and galvos were only $60 , so it was low risk if anything went wrong which in the end it didnt , so its really for you to decide as mistuned galvos/amps might cause another galvo to go pop

Paul

[Picasso]

Medialas liked to use Cambridge Technology and made some scan amps for them as well. I bet you just have a power supply to a scan amp bad or you have blown the fuse on the galvo it's self. You can unplug the working scanner and swap the wires with the not working one to check if its a amp problem or a galvo. Take some pictures for us.

[kecked]

word of warning. Do NOT try to plug or unplug a galvo with the power on. It will blow the fuse on the galvo. I know all to well. Trust me it goes badly..

[kamakajee]

Hello to All the Helpful Members!
Touching base on my above post.. I changed the power supply & the 'deemed' dead galvo started working ... thus thinking & under impression that the fuse has blown off I changed the fuse but never the less the galvo does not work.... any suggestion will be highly appreciated.
I should take some snaps & post them.. hope that will help in suggesting a specific remedy .

Thanks in advance to all!
Kama

[kamakajee]

Hello to All the Helpful Members!
Touching base on my above post.. I changed the power supply & the 'deemed' dead galvo started working ... thus thinking & under impression that the fuse has blown off I changed the fuse but never the less the galvo does not work.... any suggestion will be highly appreciated.
I should take some snaps & post them.. hope that will help in suggesting a specific remedy .

Thanks in advance to all!
Kama

Any help will really & highly appreciated !
Tks Kama

[allthatwhichis]

I changed the power supply & the 'deemed' dead galvo started working ...

I must admit I am a bit confused; by the statment I am quoting, the power supply replacement got the galvo working... for a bit?

[kamakajee]

I must admit I am a bit confused; by the statment I am quoting, the power supply replacement got the galvo working... for a bit?

Hi.. let me explain.. I just had a straight horizontal line being projected from my Mystiq laser , on close examination I found that one of the galvos was not working, therefore to be sure i was dealing with a 'dead' galvo I switched the power supply & vola ! I had the galvo working. So the problem is not with the galvo, I even changed the fuse on the power supply.. but no use.
Hope that explains my statement
Kama

[allthatwhichis]

So you still have a problem but you are sure the galvo is now working..? I am still confused but we can plow along...

How do you know the galvo is now working?
If you don't mind, please explain again what the problem is... You only see a horizontal line when you project what?

Have you taken the impacted galvo's input signal and sent it to the other galvo?

It sounds like a wiring problem from my confused perspective. Swapping the input signals between galvos should tell you where the issue lies. If you put the impacted (I think Y galvo) galvo's signal to the other scanner and the problem moves it is a connection problem; if the problem stays with the originally impacted galvo the problem involves the originally impacted galvo or its amp.

[kamakajee]

So you still have a problem but you are sure the galvo is now working..? I am still confused but we can plow along...

How do you know the galvo is now working?
If you don't mind, please explain again what the problem is... You only see a horizontal line when you project what?

Have you taken the impacted galvo's input signal and sent it to the other galvo?

It sounds like a wiring problem from my confused perspective. Swapping the input signals between galvos should tell you where the issue lies. If you put the impacted (I think Y galvo) galvo's signal to the other scanner and the problem moves it is a connection problem; if the problem stays with the originally impacted galvo the problem involves the originally impacted galvo or its amp.

I think you have got it, but still let me walk you through the whole problem... lets try once again .. I had two laser connected with a 'y' cable. On firing up the laser, one laser played the cue perfectly but the other just shot a horizontal line. On looking closely I noticed one of the mirror on the galvo was just static there was no movement.

I switched the power supply from the 'stationed' mirror to the other galvo & the problem moved to the other galvo. So I guess the problem is not with the galvo but with the connection, I changed the fuse.. but no use the problem still persist.
& yes one more thing.. when both the laser were connected with the 'y' cable, the moment I powered on the problematic laser I saw a distortion in the image projected by the other laser.

Hope I'm clear now

[dsli_jon]

Sounds like you need to a) make sure you have +24V DC (referenced to 'common'), coming from the one-supply, and -24V DC, ref'd to COM, coming from the other... If it's not the 'fuse' of one of the supplies, could-possibly be a 'bad output' (either + or -); If both are good (+/- 24), b) check that the power-connections to both pairs of scan amps are solid - no lose male terminal pins / solder joints / female plug-pins .. +/- 24V DC @ each of the XY-pair amps' power-input terminals (..power, not 'signal'..)

..Of course, also-verify your signal-integrity to each scan-amps' signal-inputs, and try a different 'Y' cable; Then try each PJ, separately, with a 'single-ended' (not a 'Y' splitter..) as-well..

Check these things and report back to base..
cheers
j

[taggalucci]

A block diagram showing the wiring and which wires you swapped to get the "dead" galvo working again would be helpful, so we know which "power supply" wires you swapped round.

[kamakajee]

Corporal Kama reporting back to base Sir ,
I was able to take some some snaps, & i'm a total novice when it comes to electronics.. so please bear with me.
In pic 1 - when I switch the white plug between a & b galvo, the problem also moves from a to b.
In pic 2 - what I feel are the fuse, when I change it with a new one, there is no change in the problem.
Will appreciate if I could be directed as to what 'may' be the possible problems.
Thanks
Kama
Pic1.jpg
Pic2.jpg
IMG_2029.JPG

Sounds like you need to a) make sure you have +24V DC (referenced to 'common'), coming from the one-supply, and -24V DC, ref'd to COM, coming from the other... If it's not the 'fuse' of one of the supplies, could-possibly be a 'bad output' (either + or -); If both are good (+/- 24), b) check that the power-connections to both pairs of scan amps are solid - no lose male terminal pins / solder joints / female plug-pins .. +/- 24V DC @ each of the XY-pair amps' power-input terminals (..power, not 'signal'..)

..Of course, also-verify your signal-integrity to each scan-amps' signal-inputs, and try a different 'Y' cable; Then try each PJ, separately, with a 'single-ended' (not a 'Y' splitter..) as-well..

Check these things and report back to base..
cheers
j

[taggalucci]

Great, thanks for the pictures. This clears up some confusion...

When you said "I switched the power supply", I think we all thought you meant you swapped the connection between the power supply and the drivers, not the connections between the drivers and the galvos (which is what you actually swapped).

There is likely to be an issue with one of the drivers (not the galvo), or there is a problem with the power to that driver or the signal to that driver.

Keep the galvos connected to their original drivers. Now can you try swap the signal inputs (white plugs) on the drivers and see if the problem swaps? If the problem swaps the the control signals/wires are bad, if the problem stays the same then the driver is likely to be faulty.

[ImageLight]

Possibility of a bad Ilda cord? Was it the second projector in line?

[kamakajee]

Hi when you say 'second projector in line' I guess you are referring to my later problem of the image flickering on connecting the problematic projector? if so, yes the projector was connected. I have tried all possible, what a novice person like myself can do.. but I'm unable to rectify either of the problem.. any further suggestion??

Possibility of a bad Ilda cord? Was it the second projector in line?

[taggalucci]

any further suggestion??

How about providing detailed information as to what you have changed around and what results you get. I have suggested some things, but you have not yet provided responses to those tests.