Thermal Dynamics Pak Master 38 XL - anybody have a main board diagram?

[greenbuggy]

Have a TD Pak Master 38 XL plasma cutter I bought at auction for cheap. Has a "DC OK" light that is supposed to light up when the cap bank is at sufficient voltage but doesn't, popped the cover and the DC bus on the cap bank is at 296 volts which seems about right for an unregulated DC supply when powered by a 220V source. Anybody have a diagram for the main board? Got a copy of the user manual which outlines the major stuff like rectifier and cap bank but nothing deeper than that. AC OK and GAS OK lights light up and nothing on the main board appears to have let the smoke out, just trying to get this thing up and running again.

[Rondo]

Have a TD Pak Master 38 XL plasma cutter I bought at auction for cheap. Has a "DC OK" light that is supposed to light up when the cap bank is at sufficient voltage but doesn't, popped the cover and the DC bus on the cap bank is at 296 volts which seems about right for an unregulated DC supply when powered by a 220V source. Anybody have a diagram for the main board? Got a copy of the user manual which outlines the major stuff like rectifier and cap bank but nothing deeper than that. AC OK and GAS OK lights light up and nothing on the main board appears to have let the smoke out, just trying to get this thing up and running again.

Call TD. 800 426-1888 wait for the TD prompt. They have service manuals or archives with what you are looking for. No parts avail anymore but give it a try.

[ccawgc]

DC light only come on after the trigger is pulled. If it stays on then were good, torch may be bad. If it flashes on then off, torch is shorted.
electronics are all on one pcb. obsolete years ago. Sometimes a damaged torch will burn up a resister in the trigger circuit near where the trigger plugs into the pcb.

[greenbuggy]

Call TD. 800 426-1888 wait for the TD prompt. They have service manuals or archives with what you are looking for. No parts avail anymore but give it a try.

Got a service manual, sadly doesn't have any board level diagrams and emailing TD they say they can't get a new board and don't have any diagrams for this machine

[greenbuggy]

A reminder to try and apply the KISS principle to your diagnostics....plasma is working again, wasn't a board fault as I initially thought, but a problem with the PIP (parts-in-place) circuit on the torch head. Putting this diagnostic info out there for anyone else running across this thread in the future.

After disassembling the torch, discovered that the PIP circuit is in series with the switch, there's 3 wires coming down the torch cable, white, black and red, red is for the arc initiation, white and black are what signals the main board to fire the air solenoid and shortly after, fire the high frequency. Inside the torch the white wire runs to the trigger switch, other side of NO trigger switch goes to orange PIP contact, other PIP contact connects to black wire. When the cup is tightened down a copper or brass ring connects the PIP contacts so when you pull the trigger there is continuity. Previously when checking this out pulling the trigger had made air flow after the initial air purge so I assumed all was ok, but when I went back after it tonight had no continuity between white and black. Suspect a cracked shield cup making the PIP contacts bind, for now PIP is bypassed inside torch head but I've got a set of new torch parts on order so I can make this all work as factory.

Also worth noting, there's separate manuals for the torch and plasma power source, and I couldn't find the torch manual on the TD (now part of Esab) website, found a dated copy from 2004 on one of the godawful manual library websites that google brings up, which has some wrong part numbers for consumables. Electrode shown on the plasma body is a 9-6506, electrode in the parts manual is a 9-6542 and while the outside end looks similar I think the rest of the electrode is different enough that it won't fit, as the older torches like I have don't have a detent to hold the electrode as the newer Surelok torches do.

[Brand X]

Very few 38XL came with a PCH 42 torch (that has 2 different handle styles) The 9-6542 electrodes are very expensive,and what that torch uses.. I put one on my mint 38XL and it worked well.. I had to use PCH 28 torch on my old machine. Cheap electrodes in that one, and knock offs work well enough. 9-6506. My 35c air unit uses the PCH-42, and I would love to adapt to a PCH-28 just to run the cheaper electrodes with it.. Torch is way smaller too.

The pip will be problematic by using aftermarket cups.. They can work with the 9-6500 nozzles sometimes, and not with the 9-6501 drag ones..

I put a adapter to run a SL-40 /SL60 torch on a 38XL with success. These 38XL have a bit more power on 120 volt then the later Thermal machines.. Tough units.. I had three since about 1999 .

[greenbuggy]

Very few 38XL came with a PCH 42 torch (that has 2 different handle styles) The 9-6542 electrodes are very expensive,and what that torch uses.. I put one on my mint 38XL and it worked well.. I had to use PCH 28 torch on my old machine. Cheap electrodes in that one, and knock offs work well enough. 9-6506. My 35c air unit uses the PCH-42, and I would love to adapt to a PCH-28 just to run the cheaper electrodes with it.. Torch is way smaller too.

The pip will be problematic by using aftermarket cups.. They can work with the 9-6500 nozzles sometimes, and not with the 9-6501 drag ones..

Don't know if my machine has an aftermarket cup or not on it, but the cup does have a crack so its getting replaced either way.

My inference about the electrode is based on the part numbers listed on the top of the machine and what the parts in the torch parts kit tucked into the cable wrap assembly looked like, there's nowhere in my torch for the circled part to go, and the electrodes that are currently in there are flat and shorter, as well as being silver rather than copper colored unlike the one pictured

[Brand X]

It probably takes the older style 9-6506 style in your torch.
They came in either copper or plated from Thermal No difference It's what most of the 38XL came with.

https://www.ebay.com/itm/Thermal-Dyn...QAAOSwcp5fVTiH