Four things needed for proper spot welds..Heat, current, time, and clean,
properly prepared tips of the proper material. Dirty tips are a likely
culprit, if you have used it before. It is a sensitive area. Lightly
sandpaper and retest. I assume you're attempting to weld steel? Nonferrous
materials like brass and such require capacitive discharge welders, in my
experience.

RJ

"kklein" wrote in message
...
Need help with Miller spot welder. It's a LMSW-52. I bought at auction
while back and don't really have a steady use for it, but sometimes
something comes up and I'll try it. At first it would weld but now I
can't
get any heat out of it. The transformer hums but no weld. Any tips on
what
to check or look for would be greatly appreciated. Anybody have one of
these?
kk