Help! Galvo's failing

[borgqueenx]

For some reason my galvo's are failing.
here is a photo:
http://d.pr/i/3o7y
(its the galvo to the right of the photo)
They do both get into normal position when they are powered on.

I was turning one of them because the beam was firing a bit off the centre.
Then all lasers suddenly went offline and i heard a steady squeek sound. squeek......squeek.......squeek. Like in one squeek per second.
Tried turning it back again and laser fired again. so i tried again and begin squeeking again. Now i can put the galvo however i want but the squeeking doesnt go away and lasers keep being offline.

What do to?
keep having problem after problem...

EDIT:

What da fuuu***** i dont understand any of this anymore.
Im not touching this device until i can get some help, im totally lost.
Now the galvanometers work again for some reason i do NOT know. i just touched the galvo that fails and it works again for some reason and scans my green beam correctly now and is set the way i want.
BUT....the blue laser is not working anymore. the led of the flexmod P3(where the blue laser is attached to) is blinking.
if the led of the p3 goes on it means there's a error. but i dont understand what it means if that led steadily blinks.
I also have the feeling it blinked when the galvos made the weird noise. because i saw some red blinking in the background of my eyes. the blue stopped working when the galvo's started doing weird too.(i could see because blue always has standby power. then standby power was suddenly offline, thus the whole laser went offline)

hopefully i didnt screw up the blue diode again that would suck ALOT! but i didnt touch any parts of the blue module so this is really not making any sense to me.

[svandescheur]

wow Boaz, that sounds really bad...
Maybe some problems with the psu ??
Or grounding problem ??
Can you do graphics without any problem ??
Not any weird lines or curves ??

Maybe the scanners need some oil ???

Good luck !

[borgqueenx]

wow Boaz, that sounds really bad...
Maybe some problems with the psu ??
Or grounding problem ??
Can you do graphics without any problem ??
Not any weird lines or curves ??

Maybe the scanners need some oil ???

Good luck !

thanks for trying to help mate!

I have looked at the PSU and it gives a steady 6.1V.
for the rest....i dont know, this doesnt make sense. i dindt touch any of the parts exept the motor of the galvo. And for some reason blue then stopped working.
I really really really cant understand the logic of this failure. When i installed blue i pulled a bit on all wires and connector to make sure all connection were tight - and they were!

[buffo]

Check the output transistors on your power supplies and your laser drivers. If any of them have the mica insulating pads that separate the metal tab on the back of the transistor (assuming a T-220 package) from the heat-sink, REPLACE the pads. (This assumes that the heat-sink is connected to the baseplate or otherwise grounded in some way.)

I had this exact problem 3 years ago, and I spent a long time looking for the source. It turned out to be a transistor in the driver for my Lasever green laser. The mica pad had a pinhole in it, and this was leaking +5 volts to ground. Not enough to blow any fuses, but enough to wreak havoc with my projector. I had the exact same issues with the galvos. (Locked to a position that is nowhere close to center, with a screech and a "pulse" of movement every second or so.)

If that doesn't solve the problem, then another source could be a short in the cables connecting the scanner amps to the scanners themselves. I have that issue right now with one of my projectors. If the cable is moved just right, it shorts to ground, which causes the galvos to freak out. It also trips my interlock... Looking for a new set now.

Adam

[borgqueenx]

Blue fails, but you think it could be something in one of the green drivers?(got 2 because 2 heads)

[michelrietveld]

So just to check
1. everything worked fine
2. you turned the projector on and displayed a picture
3. you unscrewed one of the galvo's in orde to reallign the image
4. when turning the sound from the galvo started and lasers turned off
5. you turned the projector off
6. bolted the galvo and turned the projector on again
7. it worked
8. now all lasers appear offline but galvo's work?

is this a correct summary?

[borgqueenx]

fixed already...
problem is i dont know what fixed it. could happen again....with some luck it will only happen again when editting galvo's, and that should not be nessacary again.

this is what happened.
1. displayed picture.
2. beam was off so wanting to reallign galvo just a bit so the center image would be in the center/front of the projector so i started turning the galvo a really little bit.
3. Suddenly blue laser went off(didnt use green in image) and galvo started making noise pulses.
4. immediatly cut power.
5. try again after putting galvo back where it was, worked again.
6. tried again, then it did desame and stayed behaving like that even when putting galvo back.
7. remember checking the power supply of the 445nm laser and waited about 5 hours or so before retry.
8. everything works.

.... weird.

[andyf97]

isolate the scanner block from the base plate.

[borgqueenx]

How can i do that while maintaining desame height?

[svandescheur]

Hey Boaz,

I have been thinking about that
Because my red is a little bit too low.
You can use thermal pads like this :
http://www.ebay.com/sch/Thermal-Comp...%2520Pad&rt=nc