Where To Start ..?

[ThermO]

I am trying to fix a couple 'quite new still'
"TW163 Thermocouple Welder's" that just stopped spot welding.
There are 5 of them, and it seems almost like they are all faulty
(yes, sent them back for warranty repairs already, but they are goofed again)
Batteries strong @ 12.7Volts..can't wait the months it takes to get them done again,
What/where is the issue on these things do you think?
Caps? (non are exploded/leaking)
All other components not burnt, or any obvious damage
Where to start..?

Exact model can be seen in last pic here:
http://www.maritimestress.com/thermo_weld_units.html

 

[kellys_eye]

Only two real areas to look at - the controlling switch (to discharge the capacitors) and the capacitors themselves.

In my experience (of electric fence energisers), systems that rely on heavy discharge of capacitors to provide a pulse invariably suffer capacitor failure/degradation. Occasionally the switching device goes 'open' (sometime shorted, but not often).

Short-circuits and open-circuits are relatively easy to diagnose but the simplest way to prove a capacitor fault is just to replace them. Get a replacement and wire it in parallel with the existing capacitor first - it may just restore operation to prove the issue. Then swap out as necessary.

Pics of the internals would help a lot though.

 

[ThermO]

.
Pics of the internals would help a lot though.

Thanks a ton kellys!!
I have pics,
but the driver to upload from my cell to computer is now
down/missing/corrupted.. I scored the iinternet for the internals, but no luck.
There's 2 big Caps & 1 smaller one.

 

[dorke]

ThermO,
Please take care those caps are very dangerous !!!
Properly discharge them before handling and check with a DVM that they are discharged ,
don't ever short them !

 

[ThermO]

You Bet !!
And
Thx!!