Coherent Sabre Issues

[MrNIFty923]

I recently woke up a Coherent Sabre white light from its extended hibernation. Was able to get it to lase initially, holding steady at about 6.5 watts. Everything seemed stable and running good the first couple of times I ran it. However, on the third startup I started getting some buggy electrical issues. On power up, the remote would throw an over temp error code, then that error code was replaced by a line phase error code. Now all I get is a line phase error code, and I can’t move beyond that. The line phase is correct, as it was lasing just fine on the previous startups. I did have an unusual chatter from the contactor assemble within the power supply during the countdown timer delay on a previous delay sequence.
What I need is the maintenance service manual, with electrical schematics would be nice as well. The operators manual is large, but doesn’t contain more detailed troubleshooting information, beyond “schedule a service call”? Does anyone have a service manual or schematics? Or recommendations for suggestions.i thought anbout replacing the main board or remote to start with. Also, where is the temp sensor located?

[mixedgas]

I have a service manual for its non-white-light cousins 208V version . My guess that 60-80% will be the same. Photocopying is well neigh impossible, as the manual is several hundred pages with some odd sized foldouts. It probably weights 10-12 pounds.
Manual was a gift from long ago when I received a donation of 8 units of UV lasers, PSUs and Chillers to my then employer. That customer was important enough to "C" to have a manual and he tossed it in the truck.

You'll have much more passbank. But I doubt there will be much difference in the motherboard, but I could be wrong.

Hopefully

Let me look at the flow switch and the phase sensing. Coherent made its own version of Proteus Flow switch.

You can't willy-nilly replace anything, its a matched set of head and PSU, and there are little storage EEproms (socketed) that need to match, or the unit will shut down after 20 minutes. Without a Service EPROM you cannot reprogram the tiny memory chips.

Steve

[MrNIFty923]

I have a service manual for its non-white-light cousins 208V version . My guess that 60-80% will be the same. Photocopying is well neigh impossible, as the manual is several hundred pages with some odd sized foldouts. It probably weights 10-12 pounds.
Manual was a gift from long ago when I received a donation of 8 units of UV lasers, PSUs and Chillers to my then employer. That customer was important enough to "C" to have a manual and he tossed it in the truck.

You'll have much more passbank. But I doubt there will be much difference in the motherboard, but I could be wrong.

Hopefully

Let me look at the flow switch and the phase sensing. Coherent made its own version of Proteus Flow switch.

You can't willy-nilly replace anything, its a matched set of head and PSU, and there are little storage EEproms (socketed) that need to match, or the unit will shut down after 20 minutes. Without a Service EPROM you cannot reprogram the tiny memory chips.

Steve

Thanks Steve. I was looking through all the manuals I have and I was able to find a complete Innova 100 Series service manual. Honestly, I have no idea where it came from. It’s a monster 3 ring binder. It has detailed diagrams and schematics of power supply and laser head. It is somewhat similar to the Sabre, but only in a few areas. I did find some helpful information in there. Anything you find in your manual would be greatly appreciated. I’m just going to swap out the thermostat, to try and resolve the over temp issue. As for the line phase order, it seems if the phases are physically correct, it was running fine initially. Then whatever component inside the power supply that does the initial phase detection on startup, would be the problem. It’s got to be the first thing that it does on startup. If it’s a decreet electrical component that is missing reading the line arrangement, that would be easy to fix. If it’s a motherboard glitch, that would be a more of a problem.
IMG_5750.jpeg

[laserist]

Have you considered the possibility that you've lost a phase or one has too much resistance? It's happened to me several times and it's the simple stuff that's the worst...

[mixedgas]

Bad news. My manual for the "Housekeeping" board does not have the phase sensing for each phase. They do it another way at 208. Your looking for three dual optocouplers, six plain optocouplers, or three to six miniture transformers. Otherwise they just monitor the DC voltage at the filter and gate the SCRs / MOSFETS / IGBTS accordingly.

Need to see more pics to be of any further help. HV fuses have been known to be an issue after storage, and some but not all are semiconductive after they blow. Can fool a meter once in a while. Usually I test them under load on a bench supply, but that was "back in the day", I havent touched a 440 laser in like 10 years.


I'll scan you in the flow sensor as soon as I can and post it here.

Remote is the same, motherboard looks very similar, but no phase information in mine. If you contact Coherent service with a head serial and a PSU serial, and if they match, they usually are pretty awesome with hints on such matters, if not fragments of what you may need.

Steve

[MrNIFty923]

I appreciate all the help. I’m going to check the resistance of each leg, meter all the fuses, probably pull the contactor and clean/grease it. Also, remove an additional set old cam lock connectors that were suspect and severely tarnished.

[buffo]

I did have an unusual chatter from the contactor assemble within the power supply during the countdown timer delay on a previous delay sequence.

This chattering sound could be an indication of a failing contactor, or it could be that the control voltage to the contactor is low. Neither is good.

I'd check that unit thoroughly. If the pull-in coil is weak, you often hear that chattering sound; this will cause arcing between the contacts on one or more phases, which might explain the line phase error...

Any chance you can disassemble the contactor and check the internal contacts? (Most of these are sealed units, but I've seen older designs that could be taken apart to get at the contacts.) If you see lots of arcing scars on the contacts, you definitely need a new one.

If the chattering continues, and you're sure the control voltage is right, I think I'd replace the contactor regardless.

Adam

[MrNIFty923]

This chattering sound could be an indication of a failing contactor, or it could be that the control voltage to the contactor is low. Neither is good.

I'd check that unit thoroughly. If the pull-in coil is weak, you often hear that chattering sound; this will cause arcing between the contacts on one or more phases, which might explain the line phase error...

Any chance you can disassemble the contactor and check the internal contacts? (Most of these are sealed units, but I've seen older designs that could be taken apart to get at the contacts.) If you see lots of arcing scars on the contacts, you definitely need a new one.

If the chattering continues, and you're sure the control voltage is right, I think I'd replace the contactor regardless.

Adam

Thanks. I’m not going to bother messing with disassembly of the contactor. It’s hermetically sealed. I’ll just replace it, whole hog. Bye bye. Plenty on eBay for bargain price. That’s got to be the issue. I will update on the repair!