Aluminum weld problem

[H80N]

Ok folks here is my problem, I have a syncrowave 250 that I bought new 18 years ago and just recently while doing an aluminum job the welder started acting up. The weld bead is not smooth and shiny as usual it looks like the frequency is to high and is etching the weld bead I have checked the gaps, changed gas bottle and made every adjustment I know of. If anyone has had this issue any input would be greatly appreciated.

PICS of welds pls...

have you tried substituting another "known good" TIG torch..??

water cooled or air cooled...??

Have you measured gas flow at the torch cup... you may have a clogged gas diffuser in the torch collet

[Skunk1]

Ok folks here is my problem, I have a syncrowave 250 that I bought new 18 years ago and just recently while doing an aluminum job the welder started acting up. The weld bead is not smooth and shiny as usual it looks like the frequency is to high and is etching the weld bead I have checked the gaps, changed gas bottle and made every adjustment I know of. If anyone has had this issue any input would be greatly appreciated.