Need Assistance with Verdi V5 and FAP-1

[haltan]

Hi anyone that can help is appreciated. My verdi v5 pumps a home-built ti:Saph laser. Two days ago I had a problem with my UPS that's behind the coherent Verdi V5 power supply while the laser was on standby mode - basically the UPS was giving a fault warning. So I did a shut down procedure (cooled the LBO) and then turned off the Verdi V5 and then turned off the UPS and turned back on a again the UPS and saw that it was working fine. So after waiting a day this morning I turned on the V5 using the cold-start procedure. Waited about 2-3 hours and then turned on front key, after for my power level setting of 4W the diode current ramped up to a similar level (a little higher than usual, typically it would be at like 22.8A but ramped up to 23.1A). Then I opened the shutter and the laser power was very low and it tried to ramp up the current to achieve 4W and basically the current went up to 35.4A max after which it gave an overcurrent fault and started the shutdown count. As I lowered the power to less than 0.04W I saw that the laser would stay on and the current levelled at 26A. My laser is pretty old (2005). It is chiller supported and the chiller works fine. The diode has 11k hours on it. I am worried it is a FAP-1 problem but a new one is out of budget and I don't know what type of FAP-1 I could purchase and test to solve my problem. I am attaching photos of the FAP-1. If anyone can offer thoughts on whether my problem can be fixed with a FAP-1 replacement and what type of spec I should look for in a replacement FAP-1 for my 5.5W max verdi V5 I would appreciate it. I am attaching photos of my current system

[kecked]

Hi anyone that can help is appreciated. My verdi v5 pumps a home-built ti:Saph laser. Two days ago I had a problem with my UPS that's behind the coherent Verdi V5 power supply while the laser was on standby mode - basically the UPS was giving a fault warning. So I did a shut down procedure (cooled the LBO) and then turned off the Verdi V5 and then turned off the UPS and turned back on a again the UPS and saw that it was working fine. So after waiting a day this morning I turned on the V5 using the cold-start procedure. Waited about 2-3 hours and then turned on front key, after for my power level setting of 4W the diode current ramped up to a similar level (a little higher than usual, typically it would be at like 22.8A but ramped up to 23.1A). Then I opened the shutter and the laser power was very low and it tried to ramp up the current to achieve 4W and basically the current went up to 35.4A max after which it gave an overcurrent fault and started the shutdown count. As I lowered the power to less than 0.04W I saw that the laser would stay on and the current levelled at 26A. My laser is pretty old (2005). It is chiller supported and the chiller works fine. The diode has 11k hours on it. I am worried it is a FAP-1 problem but a new one is out of budget and I don't know what type of FAP-1 I could purchase and test to solve my problem. I am attaching photos of the FAP-1. If anyone can offer thoughts on whether my problem can be fixed with a FAP-1 replacement and what type of spec I should look for in a replacement FAP-1 for my 5.5W max verdi V5 I would appreciate it. I am attaching photos of my current system

you have another problem if you change the fap. They are serialized and won’t run in a different unit. There is a way to defeat this but I don’t know it. Try temp tuning first.

[haltan]

Thank you for the warning, I did not know that they may be keyed to their serial number. I can not do any temperature tuning I tried but the laser says that required power level is not reached for LBO temperature optimization. I don't know how to change the temperature manually on the other parameters such as diode and etalon. The chiller is operating normally and I regularly flush the system monthly with an alcohol/di water mix.

[mixedgas]

How many hours on the diode?

Steve

[haltan]

The diode has 11100 hrs and the head has 10400hrs

[VDX]

... depending on presets and use this could be near end of lifetime for the diode(s)! -- some vendors intentially "overdrive" the diodes slightly, so they will "age" noticeably after some ten thousand hours ... pretty good for the "replacement-service"

Viktor

[mixedgas]

That version of the laser is not known for long FAP lifetime. I suspect you need at the FAP replaced. Last I heard this was just under 8,000$ perhaps two years ago. Probably time to have a talk with Coherent support for diagnostics, and then Coherent service, although we have one professor at work who has done this himself.
He has many of their products so they might have made a dispensation for him.


Steve

[kecked]

That version of the laser is not known for long FAP lifetime. I suspect you need at the FAP replaced. Last I heard this was just under 8,000$ perhaps two years ago. Probably time to have a talk with Coherent support for diagnostics, and then Coherent service, although we have one professor at work who has done this himself.
He has many of their products so they might have made a dispensation for him.


Steve

there is a way to get around the serial number but I don’t know it.

[Loic74650]

Greetings
I don't think the diodes are "serialized". They have an EEPROM inside which holds 6 fields of data, see below a typical EEPROM content:

1. Header: V18
   
2. Diode temp. setpoint (°C): 23.30000
   
3. Diode hours (H): 9004.83007
   
4. Diode wavelength (nm): 810.49578
   
5. RCM: 55.00000
   
6. RCF: 0.02000
   

Perhaps what was meant by serialization is the header tag "V18" which perhaps prevents it from running in another type of Verdi (never tried it in another laser), but that can be overwritten, hence not a big issue I think.
There are plenty of second hand FAP modules on eBay but most would be wornout. You need to get lucky.
Finally you can also override the RCM parameter in the EEPROM which is the max current at which the laser will run the diode, perhaps that lets you squeeze a bit more juice out of it...