Want to buy: Liconix 4240PS Power supply

GooeyGus · Post by **GooeyGus** » Fri Jan 30, 2009 3:32 am

Hello everyone,
I'm trying to get into holography and I recently acquired a liconix 4240N dual discharge 442nm HeCd laser. The laser worked great the first day I got it and it ran for about 6-8 hours without incident. I turned it off that night and went to start it the next morning, but half of the power supply was dead. I tried to repair it to no avail, it looks like one of the HV modules in the PSU went into self-destruct mode.

Anyway, I'm desperately needing a power supply for this unit. The power supply is a liconix model '4240PS'. This is the model with two HV connectors (because the tube is dual discharge) as well as the laser control connector. If anyone has a unit they would be willing to sell me, I would be very grateful. If you have one you're willing to part with, please send me a PM or e-mail me at EMGGuitarBoy at hotmail dot com 8)

142laser · Post by **142laser** » Fri Jan 30, 2009 5:54 pm

Hello,
That is really bad luck; the power supplies usually outlast the heads with no issues. I would check e Bay every week and program a search for Liconix. You should be able to get a supply for around $100. Even if not working right one of the modules should be good right? Best wishes, Phil 142laser

DPetreycik · Post by **DPetreycik** » Sat Jan 31, 2009 4:22 am

Hello,

The Liconix 4240 laser is great for DCG holography!

I have a complete system, but the head has gone just beyond its usefull life and shuts down during warm up. The power supply is still going strong and BOTH HV discharge outputs still work fine. I am looking to sell THE WHOLE SYSTEM because a refurb on the head is costly.

Let me know if you are interested.

Regards,
Don

142laser · Post by **142laser** » Sat Jan 31, 2009 12:47 pm

Hi Don,
Unless the tube is high hours and the Cd is gone it may come back with a week or two on. You must defeat the start timer long enough to get both sides to maintain; then leave it on for a week. MG used to provide this information but for liability reasons they will not any longer. I have a modified supply and will try to dig up this information ( a pin on a chip to pull down I think); the laser is burried under junk at the USF Physics Department. It is a good idea to remove the ballast resistor covers first (with the power off and laser unplugged after sitting) as the HV may jump to ground there and kill YOUR supply module. Best, Phil 142laser

Jeffrey Weil · Post by **Jeffrey Weil** » Sat Jan 31, 2009 10:38 pm

I have a 4620 supply. I think it will work but not sure. Its def 2 discharge. I haven't used it in a few years but last I did it ran fine.

Jeffrey Weil
NorthBeach Holography Inc.

142laser · Post by **142laser** » Sat Jan 31, 2009 11:52 pm

I would ask Amir at Melles Griot before trying a different model supply......BOOM, smoke...

Best wishes, Phil 142laser

GooeyGus · Post by **GooeyGus** » Mon Feb 02, 2009 5:05 am

I've been in contact with Amir at melles griot, originally for a repair quote on this supply. I was actually quoted for only around $750 for a repair, which isn't bad because other companies were wanting $1500!! Still, it is a bit more pricey than waiting for a surplus supply to show up on ebay for $100. I am confident I will find a more affordable working supply, but it is good to know that if I decide to get it refurbished, Melles griot will do it for a semi-reasonable price. I just e-mailed him to ask him about the compatibility of my head and the 4620 power supply. Hopefully I will hear back tomorrow as it would be really nice if I could buy this supply from Jeffrey. Also, if Don decides that he does want to sell his setup, that is also a great option. Hopefully I can figure out something this week to get my wonderful HeCd working again.

It sure was great while it was working!!

DPetreycik · Post by **DPetreycik** » Tue Feb 03, 2009 4:25 am

Hi Phil 142laser,
In an act of desparation, I tweaked the trimpot near test point #5 on the PC board under the little access panel on the head and it started lasing again. It is now brighter and more stable than ever. I ran it for two hours last night, but turned it off in fear of frying the head (I do not know what I am doing with that adjustment). Do you know the procedure for adjusting the four trimpots on the PC board? I will e-mail Melles Griot (Amir?) as well.
Best Regards,
Don

GooeyGus · Post by **GooeyGus** » Fri Feb 06, 2009 7:45 pm

Well after exhausting all my resources for the last two weeks, I've decided to send this power supply back to Melles Griot for a complete rebuild with oem components. The price is a flat fee of $750, regardless of what is wrong with the power supply. There is a 4-week turnaround time, so I have to wait a little bit, but when I get it back it will have a warranty and documentation proving that the work was done on it and everything. It is a bit pricey compared to buying a surplus supply, but I just haven't been able to find ANY surplus supplies, not to mention cheap ones. I figure I can spend $200-$500 on a surplus supply, or I can spend a few more dollars and get it fixed and know that it will easily outlast the head. In case you're wondering, a brand new 4240N head from melles griot is $12,000

. So when my head dies I'll just find another surplus one... haha.

dave battin · Post by **dave battin** » Sat Feb 07, 2009 12:15 am

if you could wait it out , i always see these power supplies go up on the big "E",as im always looking for a good tube (single, not double like yours) ....... and then they break in shipping! well thats what insurance is good for

sooner or later a power supply will come up. With the money you save get a nice diode laser !