This one's for you, Dave. *Now with pictures*

Well the laser has been shut down for the night. It ran foranother 5 hours or so with no issues whatsoever. Everyone burry your frogs tonight and hopefully it will work tomorrow.

Oh yeah, make sure the frog is pointing towards Washington state.. especially you, dave!

awesome find! is that thing running at 442nm or 325nm? It sounds like you can see the spot, but it seems a little too purple to be 442 in the pictures. Maybe a mix of both?

In any case, sorry to hear about the power supply. If it were me while it was running (being careful of the hv everywhere) take some baseline measurements on what the signals should look like so that if the frog juice runs out you will at least have an idea of where to look. All else fails I vote you hook it up to a pile of neon sign transformers and see how long it lasts ;D

Well the PSU wont fire the other side today. Go figure. Ugh... so sick of this.

The laser is 442nm, my camera just has a hard time picking up the color

GG -- You have had this running long enough to get it "enlightened".
Now --- You say it's a split supply -- is there a possibility of a temperature sensative component in there causing the failure between right and left??? Would a warm room help it start ??
Also, you have some issues with power from the line ?. 3 phase? Balanced 240 volt ??
This tube should light up right now with power -- you have cooked it enough.

Mike

I feel like the king of the world when I figure things out in my head and then it works in practice!!!  

So here's the deal. The power supply has four big power transistors, two for each side of the PSU. Each set of transistors is matched, meaning you cant just start swapping them around, the pairs have to stay together. Anyway...

The power transistors drive a controller card which drives the PWM card which then drives the HV module. Ok... so I learned last night that the HV module was not the problem. Work back one step and you come to the PWM card. I know the PWM card is good or else the laser wouldn't have worked intermittently like it did last night, also I knew it wasn't getting power because the LED wouldn't come on. One step back brings us to the PWM controller card. This is where things get hairy. I knew that either this card was completely F'd or it just wasn't getting power. There's no LED indicator on this one. I decided to try the easier path first and assumed it wasn't getting power. This brings us back to the transistors. I wanted to pull them all out and swap them to the other side, this way if the other output started working and the working one stopped working, I would know that there is a bad transistor or set of transistors. So I pulled them all out, cleaned all the connections really well, applied some thermal grease and all that good stuff and got her patched together again.

I was very nervous to turn the key. I knew that each pair of transistor was matched to each other, but I didn't know if they were somehow matched to their designated HV module. It seems far fetched but these supplies are really weird. Anyway... I turned the key very slowly, and the second I heard the power relay click the head had already lit up like the griswold's house on christmas. No delay, no hard start, both sides started instantly and at the exact same time. *Whew*. I really hope my problem is solved now. Looks like it could have just been a bad connection at one of the transistors. It's lasing away as we speak so hopefully everything is good to go now!!  

~ smiles

I didn't think that the driver transistors are the problem ---- Only the driver circuits. Lase on GG

Mike

I'm about to just give up on this thing. I really thought I had it nailed away last night. Then today I go to turn it on and it does the same thing, same side, despite the transistor swap. I dont know what to try at this point.

Dude! You must have sucked in your past life . . . . . . j/k

I think that you need to take your girlfriend out for pizza.

Peace,
dave

clearly you need to ship the laser/supply/spare to me and I will fix it up for ya and keep it for all eternity

well after another two hours of tinkering I got it working again. I decided to swap the HV modules themselves. This way, if the opposite side started working and the working side was no longer working, I could trace it down to the modules. Well, keeping with the theme of "confusing the hell out of gooey", I swapped the two HV modules and then the whole thing worked again. This thing is such a tease... I get an entire night of good 442nm lasing but then I have to mess with the power supply for two hours before it will work after I turn it off!!!

I am very good at fixing things, and very good at troubleshooting, but when all my troubleshooting has the exact opposite effect that I want (well... ultimately it has the exact effect I want but it's not fixing the problem!!!) what am I supposed to do? As soon as I can replicate the problem on the WORKING side I will have my problem solved...

It looks like old gas lasers are a bit of a "hobby", eh?

Peace,
dave

The problem has been FIXED.... wahooooo. It was the PWM card. I pulled one out of my other PSU, plopped it in, and it's worked flawlessly ever since

GooeyGus said:

The problem has been FIXED

Click to expand...

How many times have you said that now?

Cyparagon said:

[quote author=GooeyGus link=1236993690/32#44 date=1237514821]The problem has been FIXED

Click to expand...

How many times have you said that now? [/quote]


This time it really is ;D

the first few times were just 'freak' incidents where the 'bad' PWM card would intermittantly click on. I verified that this was the problem by putting in a good PWM card, both sides worked. I then took it back out, put the original one in, and only one side worked. Put the new one back in again and both sides worked. I've started it about 5 times since then and it's never had another issue

Any chance of repairing the bad PWM card so you have a spare? It seems like having one around could come in handy..

Also, I was still wondering about the rated power output for a system like this..