Help Needed: Melles Griot 85-YCA Laser System Issue

[mojo]

Hi everyone,

I'm reaching out to this amazing community for some guidance. I have a Melles Griot 85-YCA laser system (561nm, 10mW) that has been running flawlessly—until now. Suddenly, the laser stopped working. Instead of the usual two orange laser output LEDs lighting up, the red LED on the controller flashes six times, and that's it—no laser output.

The controller has an RS232 interface, but it seems to have a non-standard pinout, so I haven't been able to access any additional information through it.

Has anyone encountered this issue before or knows what the six flashes might indicate? Any troubleshooting tips would be greatly appreciated. Also, if anyone has a manual for the Melles Griot 85-YCA laser system, I would be incredibly grateful if you could share it.

Thanks in advance for your help!

-mo-

[mixedgas]

Those may still be supported by a company in Rochester New York that brought the remains of Melles and did the MBA split thing. Try at IDEX Health and Science. You'll have to call for tech support., you won't find it on the website.



Steve

[hologeek]

For the blue version of this laser, 6 flashes is head read error... I might have the 85-YCA manual on a different computer, will check.
Do you have a different cable you can try?

[mojo]

Hi everyone,

First, I want to thank everyone for their responses and apologize for the delayed reply as I was on a business trip.

To Steve: Thanks for the tip. I'll try to get someone on the phone.

To Mixedgas: I didn't expected the laser head would read anything other than analog signals (looking at the controller, quite old school)... I checked the cable—nothing unusual.

Current Status:

Now, the controller no longer blinks at all. When I try to start it, nothing happens except for a brief power spike. But no more error code.

I also checked the power supply I was using. Interestingly, it seems the power supply has failed. The oscilloscope shows quite high spikes, regardless of the load. Definitely not clean 5V anymore.

After all, the controller is from 2007. Wasn't that the era of low-quality capacitors? Tantalum everywhere...

I've attached a few photos, though there's not much to see at first glance. The laser is quite well-built, but the controller seems a bit over-engineered.

Without a service manual (test points), it will be quite difficult to find the fault.

- mo -

[mojo]

I only opened the laser head for a quick look. I'm not sure if a KTP or LBO is installed. Also, nothing (bad) to see here...

[hologeek]

I have an extra MG YCA-020 controller if you want it. Just pay shipping.
Also, the contact I had at MG/Idex was a guy named Amir. I have his contact info, but last I spoke to him was many years ago...

-George

[buffo]

I seem to recall Melles Griot had some sort of serial-number matching scheme in place between the head and the PSU for these lasers, and if there was a miss-match, you'd get that head read error and the PSU would not even try to power the pump diode.

I know George Mack had a pile of miss-matched heads and power supplies at one point, and there was some talk about this mystical software from MG that would have enabled a power supply to function with a non-matching head, but I don't remember how that all ended up.

Anyone else remember this, or am I hallucinating?

Adam

[hologeek]

Adam,

I don't think the YCA's had eeprom's in them. Do you mean the Melles Griot DPSS lasers with the larger heads on air cooled heatsinks? There is old software to adjust the lasing parameters, but you needed the 'magic' password to get access the parameters.

-George

[buffo]

Do you mean the Melles Griot DPSS lasers with the larger heads on air cooled heatsinks? There is old software to adjust the lasing parameters, but you needed the 'magic' password to get access the parameters.

Yeah, that's the one! Wasn't sure if they carried that through all of the Melles Griot line, or if it was exclusive to the DPSS greens that were so ubiquitous on the MoboLaser ML-10's back in the day. From what you're saying though, it sounds like that software won't help in this case. Bummer.

Adam