Uniphase argon advanced help needed...

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03-22-2009, 08:26
dxs

Uniphase argon advanced help needed...

Hi!
I just received a nice argon set, psu 2214-40mla (the gold box), head 25mlup. It was working before it was shipped to me, and was probably really jolted during that ;-)
Actually, it does not work for me (I know... it's not "my laser is broken" forum)!
Symptoms are:
- psu correctly issues trigger signal command (5,5v across violet and green if I remember colors correctly), a bit low according to Sam's faq (??)
- I jumpered pins 1-3 and 2-13
- key is turned to on ;)
- thermal interlock on the head is a short
- I checked all fuses in the psu, they're ok
- PS is set to 220v (I'm in France), I tried with a 110v transformer on the 110v setting, no change
- I can't get the psu to output DC+ (the hv 100v). I tried connecting only the round umbilical to the psu, and I checked for DC+ directly inside the PS: still nothing else than 0v.
- checked wiring from head to plugs, everything seems fine

Any hint?
Using the PS alone with no head at all, does someone know if jumpering the thermal interlock should get me DC+ out? Will it damage anything?
I can make measures if needed.

Many thanks for help.

Edit: Pictures will follow ;-)
03-22-2009, 08:32
mixedgas

cathode lit?

Steve
03-22-2009, 09:15
Diachi

Quote:

Originally Posted by mixedgas

cathode lit?

Steve

If you can't see the cathode lit down the bore, go inside the head and measure the resistance across the two pins at the back (cathode), it should be almost a dead short.

-Adam
03-22-2009, 11:54
LesioQ

Don't forget to wait about a minute. This much time is for cathde heating-up, only then the high voltage is applied to head followed by start pulse.
Do You have a factory remote for it or just a DIY panel ?
A picture might help with help :eek:
Piotr.K
03-22-2009, 14:41
Laser Ben

A picture would for sure help. How are you controlling the power supply? Did you get the factory control panel?
03-22-2009, 16:30
dxs

Stupid me, I forgot to say. Yes, cathode is lit, voltage across it is fine (around 2,5v). Resistance is a short when cold.
I wasn't sure if HV should be applied as soon as the PSU is powered, or after the delay when trigger command is sent. When the delay expires (around 25s on this ps), the 2 contiguous red and green LED on logic board light up, and I can measure the trigger signal command at the head. But no HV, and hence no starting. I tried waiting more, up to a minute, nothing else happens (there's even no magic rabbit going out of the ps :)).
If of any interest, the red LED in the middle of the logic board is always lit.
I don't have the full blown commercial remote... euhhh... just 2 jumpers for now. I'll make the real thing the day I see coherent light out of this!
03-22-2009, 16:43
dxs

A thread if worthless without...

The head with start module visible:
http://g.imagehost.org/0543/f1.jpg

How it looks with cover:
http://g.imagehost.org/0769/f2.jpg

Inside PSU:
http://g.imagehost.org/0126/f3.jpg

Logic board, you can see the red and green LED I was talking about on the left, and the red alone in the middle:
http://g.imagehost.org/0024/f4.jpg

Head detail:
http://g.imagehost.org/0016/f5.jpg

PS detail... don't shoot at the guy who made that, I'll buy a male plug asap:
http://g.imagehost.org/0113/f6.jpg

According to Sam's Faq, using those 2 jumpers the system should be idling peacefully... Mine doesn't :eek:
While checking for HV, it's possible that a few times I saw a random voltage at the very moment when the trigger start command is issued, but so short my meter had no time to give a real value. I'm not brave enough to plug the HV output in my oscilloscope ;)
03-23-2009, 01:28
LesioQ

Interlock in OK (1-3), so is the discharge command (2-13).
I'd suggest adding IDLE (11-4) and current control (11-5), as ot me it's not sure if You order the head to run light controlled with zero power request will it issue HT at all.

Oh, and measure voltage between 13 and 11 - do You see 15 Volts ?

Piotr.K
03-23-2009, 02:28
mixedgas

Sounds like you have no drive to the fet gates, or bad FETs/Reverse diodes.

NO drive could occur if you have no potentiometer or control voltage, so I'd add the wires LesioQ suggested.

Just for a sanity check, do you see a bore flash on a white card when the ignitor fires?

remember to keep you meter away from the ignite pulse.

Steve
03-23-2009, 02:48
dxs

I'll try that LesioQ and keep you informed. Right now I'm away for my job, I'll be back tomorrow.
Steve, I have no start pulse, because on this laser, the start pulse is made from DC+ (no boost voltage). No DC+ ---> no start pulse. HV pulse is made by the blue box you can see on the head (it's written "assembly..." on it).
13-11 was checked, 15v as it should. I also checked 2-11, about 12v, so it's floating high unconnected.
Thierry
03-23-2009, 05:32
Diachi

Just a question, does the green interlock light on the front of the PSU come on ?

If it doesn't , it could be the second interlock in the head that is causing this ( if there is one in this model, I am only familiar with the insides of model 2211 heads ) this would explain why it isn't starting anyway.

EDIT: Read the first post again, if the trigger command is being issued it's probably not an interlock issue. :rolleyes:

-Adam
03-23-2009, 15:27
dxs

Actually there's an interlock in the head, it's the thermal protection. And yes I get the green Led.

I tried that:
http://g.imagehost.org/0925/f7.jpg

Still nothing out :(
At that point, I think I'll try to find someone with a working set to confirm the ps is faulty. Too bad no one has real shematics of the ps.
What else could I do? I can't think of anything I didn't try.
03-23-2009, 19:07
Laser Ben

WOW! There is a lot less stuff in those power supplies then the ones I have had! Usually there is a huge capacitor and transformer.
03-24-2009, 03:03
dxs

Maybe parts are missing in mine, that would explain it doesn't work :D
03-24-2009, 06:54
Laser Ben

Yours doesn't look like there are any major voids or cut wires in the power supply. That would lead me to wonder if you have checked for continuity in the umbilical and if you are getting discharge but not lasing due to mirror misalignment.
03-24-2009, 07:53
Diachi

Quote:

Originally Posted by dxs

Actually there's an interlock in the head, it's the thermal protection. And yes I get the green Led.

I tried that:
http://g.imagehost.org/0925/f7.jpg

Still nothing out :(
At that point, I think I'll try to find someone with a working set to confirm the ps is faulty. Too bad no one has real shematics of the ps.
What else could I do? I can't think of anything I didn't try.

Yeah I know the temperature cut off interlock is in the head, but im sure my 2211 head had a second interlock in the head.

-Adam
03-24-2009, 08:36
dxs

Thanks to all for your inputs, I really appreciate your valuable help.

Alomst hopeless, I just tore down the psu to bits...
http://f.imagehost.org/0290/f8.jpg

And guess what I found... Do you notice something on this pic?
http://g.imagehost.org/0421/f9.jpg

And now?
http://g.imagehost.org/0169/f10.jpg

Part number is 67L090. According to what I googled, it's a thermostat, 90°C, opens on temperature rise (to protect the psu from overheat as it's mounted on the main power heat sink). I checked: it's open at room temp, so basically it's dead (not a surprise I confess).
Mechanical damage was caused by stress on the heat sink, as the component opened with the back still attached on the heat sink.
I can't exclude I did this will tearing the psu, but not very likely.

I'll replace it by a short for a test, and if it works I'll source a spare.
I'll let you know if it worked or not...
03-24-2009, 09:23
Diachi

Quote:

Originally Posted by dxs

Thanks to all for your inputs, I really appreciate your valuable help.

Alomst hopeless, I just tore down the psu to bits...
http://f.imagehost.org/0290/f8.jpg

And guess what I found... Do you notice something on this pic?
http://g.imagehost.org/0421/f9.jpg

And now?
http://g.imagehost.org/0169/f10.jpg

Part number is 67L090. According to what I googled, it's a thermostat, 90°C, opens on temperature rise (to protect the psu from overheat as it's mounted on the main power heat sink). I checked: it's open at room temp, so basically it's dead (not a surprise I confess).
Mechanical damage was caused by stress on the heat sink, as the component opened with the back still attached on the heat sink.
I can't exclude I did this will tearing the psu, but not very likely.

I'll replace it by a short for a test, and if it works I'll source a spare.
I'll let you know if it worked or not...

I hope for your sake that this fixes it, then you'll get to see the lovely blue colour that argon lasers emit *warn:D:cool:

-Adam
03-24-2009, 10:12
dxs

Damn, I replaced the thermal switch by a wire...
and...

It works flawlessly guys! I'm so happy!!!
Again, thanks to all for your help!!
03-24-2009, 10:39
Diachi

Post pics or it never happened !!

Do you like the colour then ? :D:cool:
03-24-2009, 13:45
dxs

It DID happen :)

http://g.imagehost.org/0058/f11.jpg

Poor pic but I did it in a hurry as my fan burned (I won't repair that one), so it's only idling.
The color is awesome, and even at idle it gives 5 lines (maybe 6, not sure). What a great laser!
03-24-2009, 14:07
Diachi

5 lines on idle ! :cool:

Nice laser ya got there, can't wait to see some full power pics :eek: Nice one man, keep lasing *warn:cool::p

-Adam
03-24-2009, 15:08
mixedgas

*warn NICE *warn

*warn JOB *warn

Just dont aim it at any ducks while fishing....!!

Enjoy!!!

Steve
03-24-2009, 16:01
Laser Ben

OHH!!! VERY NICE!!! I can't want to get my Argon laser!
03-25-2009, 02:58
dxs

It gives 5 mw, 5 lines at idle... According to the seller, it will give 65mw at 10A, which is pretty good for a 25mw rated laser. However I'll keep it a low amps to keep it happy for a long time :)
Trust me, after all the hours I worked on that, I do enjoy!!
Thierry