Troubleshooting dead 30XP and 1000G3

[MtnMann]

Hello,

I’m trying to get two dead machines going.

The 30XP does nothing when powered up. 244v is getting to the power board just fine (past on/off switch). Voltage at R-W is 344v instead of expected 375v. Voltages at R-B and W-B are both 172v. There is no voltage at J7 pins. No lights on. No fan on. No visually apparent damage or burnt spots on components or board. I’ll call Hypertherm techs tomorrow but just thought I’d post here in case someone has tips on what to check next? I pulled the board for a better look.

The 1000 is also dead and I haven’t started checking voltages yet but the low voltage transformer has a fairly loud sound somewhere between a buzz, hum, and hiss. It continues to make that sound after turning power off until the caps drain (I’m assuming). The board is immaculately clean with the only dark spot being on the transformer coating - prob just thick coating spots rather than from heat. Any thoughts?

I am considering making an IGBT tester per schematic in service manual but is that really necessary? Can’t an IGBT be tested with a DMM in diode mode?

Thanks in advance!

[MtnMann]

After checking voltages on the 1000, inputs are fine but the IGBT, PFC is only 336VDC when it should be 750VDC. If I check it on AC, I get 748VAC and with leads reversed, I get 0? (Leaking diode in IGBT?) The IGBT, Inverter readings are 1/2 what they should be. Fault light is lit on front control panel. Power supply capacitors are correct at 372V. Also I noticed R119 gets warm after power is on for a bit but R120 stays cool.

[adbuch]

It sounds like you know what you are doing with your diagnostic testing. I would just continue along until you identify the faulty component(s). If all else fails, then perhaps a trip to your local welder supply repair shop might be in order.

David

[acourtjester]

On the 1000 you may have a shorted transformer the hiss could be arcing internally. I would ohm out the transformer's windings with the circuit disconnected. Without a schematic it hard to say what is up with the resistors.

[MtnMann]

Well, Hypertherm tech support was not exactly helpful... unfortunately I don't think I got one of their best on the phone. Almost a useless call.

On the 30XP, I noticed that one of the two big caps has no voltage. Trying to diagnose that...

The 1000 has at least 2 revisions of the service manual and there are different tests in the two versions. I was originally working from the first Rev.0 and then found Rev.1 has more tests which I will go through.

I also ordered components to make an IGBT tester from Digikey for $14. Maybe that will help to see whether I have an IGBT issue.

[weldguy]

Thats a bummer but hopefully you will get somewhere with your IGBT tester. Curious to hear what you find out.

[jteller07@hotmail.com]

For the 30XP if you don't have power at J7 then the fly back circuit isn't getting power somewhere and the power board is most likely dead the power for the flyback comes off before the PFC and the capacitors. If you haven't already, check the capacitor it should be 2200uF, if that's correct then the power board is definitely dead.

For the 1000 the machine isn't boosting that is why you are only seeing half the DC voltage you expect. Any time there is a system fault the machine won't boost. Checking the fault lights on the control board usually tell you what the issue is but if they don't make sure you have a torch connected, air to the machine and try to fire it and see if any of them come on. If they still don't then one of the two boards is failed, and neither are available from Hypertherm. You might have a problem with the transformer since it does sound like it might be shorting internally and that could be where your fault is coming from without knowing exactly which transformer you're talking about I couldn't tell you what its function is.

[weldguy]

For the 30XP if you don't have power at J7 then the fly back circuit isn't getting power somewhere and the power board is most likely dead the power for the flyback comes off before the PFC and the capacitors. If you haven't already, check the capacitor it should be 2200uF, if that's correct then the power board is definitely dead.

For the 1000 the machine isn't boosting that is why you are only seeing half the DC voltage you expect. Any time there is a system fault the machine won't boost. Checking the fault lights on the control board usually tell you what the issue is but if they don't make sure you have a torch connected, air to the machine and try to fire it and see if any of them come on. If they still don't then one of the two boards is failed, and neither are available from Hypertherm. You might have a problem with the transformer since it does sound like it might be shorting internally and that could be where your fault is coming from without knowing exactly which transformer you're talking about I couldn't tell you what its function is.

Very interesting, curious if the OP will be able to look at these things and get back to us.

[MtnMann]

Thanks for the insight! I’ve been too busy lately to continue troubleshooting but I’ll be back at it soon. I did make an IGBT tester and the ones on the 1000 test fine. Haven’t pulled the ones on the 30 to test yet. Waiting for a new desoldering station to arrive. Damn lead-free solder is a pain to desolder.

[weldguy]

Thanks for the update. Sounds like your making progress

[MtnMann]

Finally had time to dive back in. On the 30XP, found a bad U9 (TOPSwitch 247), it had a hairline crack and was just being held together by the heatsink. When I desoldered it, it just fell apart. Anybody with more experience know if there is any likely other culprit that’s related? I’m not seeing any other signs other than heat around nearby R5&6 (20k ohm) but they check out fine.

[weldguy]

I expect that would not be an easy once to find. Hopefully you get it up and running shortly. Nice work

[MtnMann]

Luckily Digikey has those for $3.37
I’ll see if that does it…

On my 1000, still troubleshooting. Pulled the proprietary transformer. No windings shorted according to DMM but figuring out how to test it with VBUS applied to primary which from the looks of the half-ass schematic should be 750VDC?

[MtnMann]

Replacing that TOPS247 switching chip fixed my 30XP.

Still working on the PMX1000. Suspecting one of the optocouplers. Probably the thickest PCB I’ve worked on which definitely makes things more difficult for removing components.

[weldguy]

That's pretty awesome! Always a good feeling to find and fix something like that and the money saved is a major bonus. Well done and thanks for posting your solution

[SegoMan DeSigns]

This has been a good read, I like people who can figure things out on the fly..