Laserworld CS-400RGY repair, help please!

[cyaniron]

I have 2 of these units. All 4 of the red diodes stopped working about 50 hours from new. The guy I bought them from in Germany wasn't too helpful, so I am on my own. I replaced all the red diodes with Rohm RLD65PZB5 diodes. I put them in the mounting 'barrels' using conductive paste. I set the current to 130mA for each diode, put the lasers back together, and after about 50 hours, all the reds are dead again.

Here is a picture of what the laser looks like inside. The brown/orange PCB towards the centre is one of the ones that controls the reds.


more photos are here: -
http://www.flickr.com/photos/26748851@N04/3589248046/in/photostream/

Has anyone got any ideas as to what is going on with these lasers?. Poor diodes?, poor driver circuits?, poor heat dissipation?, something else?.

[bridge]

Hi Cyaniron, welcome to PL forums.
for answer your questions, do you had any data sheet of RLD65PZB5? I just check it and know it is a pulse 240mW red lasers, what it's Spec of CW working? 120mW unit or just 100mW unit, it is working current is 130mW? which brand is laserworld before used?
All you mentioned all will give your problems:
Poor diodes?, poor driver circuits?, poor heat dissipation?, something else?.
Poor doides, I don't used any Rohm products, so can't say anyhing, but most people here are used ML series products.
Poor driver circuits?
from you words, 2 times are the same problems, 50hours working, so it is make me doubt the driver design, some poor driver made in China who only had TTL design, we test it and find it had over current when you TTL using, a sample, when you CW using, it is 130mA, but when you TTL using, it maybe 140-150mA then down to 130mA.
poor heat dissipation?
This is easy to know, power your doide and let it CW working(normal hours and you always using), to see the heatsink is hot or not, as laser show using is always TTL or Analogue using, which product small heat than CW using, if CW no problems, TTL or Analogue is not problems.
Something else?
Yes, most terrible is Static, the driver consider static design is very important for lasers. Lasorb is a good unit that will help you protect your doide. there also many other consider, just like voltage wave, spine etc of driver.
sorry for my poor English, wish it will be helpful for you.
Best regards!
Bridge

[cyaniron]

Thanks for your reply.
Here is the datasheet for the Rohm diodes I used.....
http://pdf1.alldatasheet.com/datashe...RLD65PZB5.html

I have a degree in electronics, but this is my first time dabbling with lasers. Anyway, I set the current at 130ma when the diode was warm, say after 5 minutes on CW. I cant remember if I measured the voltage across the diodes. I figured that this was well below what they should be capable of, and so they would last a long time. Regarding the original diodes. I dont know what they were, but they looked identical to me, ie. they were some closed can DVD burning diodes. I know that after I set the lasers up with the replacement diodes, the beams were much less bright than new, but I was happy with this, hoping that they would last a long time. Its a lot of work stripping down the laser, replacing diodes, soldering, refocussing, setting current, aligning, rebuilding. I didnt want to do it again in a hurry!

When I said 50 hours. Read 30-150 hrs, I didnt measure the time, but it was that kind of order. The original diodes lasted marginally longer.

I beleive that these lasers may have been marketed before as Big Dipper F-01, or F-01+

The red driver boards have this text on them (give or take a few letters/numbers, it was hard to read)
E246366
LDD-Red
RL250-300905
Ver 2.01

It would obviously be nice to pinpoint the problem, before I move on and figure what to do with these lasers.

[White-Light]

I'm pretty sure Laserworld doesn't manufacture these - they're bought in from China.

I had heard this and searched around and found the exact same laser casing with a different power claim (maybe Laserworld tweaked) under a different brand. Can't remember the manufacturer off the top though.

[JimmyV]

I'm pretty sure Laserworld doesn't manufacture these - they're bought in from China.

I had heard this and searched around and found the exact same laser casing with a different power claim (maybe Laserworld tweaked) under a different brand. Can't remember the manufacturer off the top though.

The brand name of the cheap unit is LANTA (350mW RGY)

[Mr.Coffee]

Hi Cyaniron, welcome to PL forums.
for answer your questions, do you had any data sheet of RLD65PZB5? I just check it and know it is a pulse 240mW red lasers, what it's Spec of CW working? 120mW unit or just 100mW unit, it is working current is 130mW? which brand is laserworld before used?
All you mentioned all will give your problems:
Poor diodes?, poor driver circuits?, poor heat dissipation?, something else?.
Poor doides, I don't used any Rohm products, so can't say anyhing, but most people here are used ML series products.
Poor driver circuits?
from you words, 2 times are the same problems, 50hours working, so it is make me doubt the driver design, some poor driver made in China who only had TTL design, we test it and find it had over current when you TTL using, a sample, when you CW using, it is 130mA, but when you TTL using, it maybe 140-150mA then down to 130mA.
poor heat dissipation?
This is easy to know, power your doide and let it CW working(normal hours and you always using), to see the heatsink is hot or not, as laser show using is always TTL or Analogue using, which product small heat than CW using, if CW no problems, TTL or Analogue is not problems.
Something else?
Yes, most terrible is Static, the driver consider static design is very important for lasers. Lasorb is a good unit that will help you protect your doide. there also many other consider, just like voltage wave, spine etc of driver.
sorry for my poor English, wish it will be helpful for you.
Best regards!
Bridge

And that, ladies and gentlemen is why I'm buying my lasers from Bridge.
That's like a Ford dealer trying to help fix your Dodge. Ya just don't see it every day.

[djlorenz]

laserworld is shit... waste your stupid red diodes and put inside a real red diode

[White-Light]

The brand name of the cheap unit is LANTA (350mW RGY)

That's the one! I'm guessing Laserworld buy these in the tweak the power levels up.

[dream beamz]

newer issue big dipper red diodes. I the second set died in both cases in the same way maybe you are getting minor back reflection from the pbc. the power supplies for these are pretty robust so i do not think you have two bad sets of power supplies.

replace or reseat the pbc at an angle and the diodes again, make sure your current is good and you should work fine. hope this helps

[cyaniron]

Dream beanz,
Thanks,
That sound like a very plausible theory.
There are 4 power supply boards that would have to have the same problems if it were them, and they look pretty good (they aren't skimpy, and have lots of components, so I must assume that they are well engineered, and that every RGY400 doesn't have this identical issue!?).
The reflections of the reds do go directly back to the source. Does this mean that in other better designed units that the cube is at a slight angle to stop this happenning?, or that the cubes are better quality in others meaning loewer reflected energy?.