I have a MX-500 that I haven't been using much because it doesn't seem to
put out the heat it once did, but works fine for small soldering  duties
(smt).  If I try to use a STTC-017 tip on a larger solder joint the tip will
cold-weld to whatever I'm soldering.  Over the weekend I opened it up and
found a 1 watt or so carbon resistor that was nice and crispy but intact.
The insulation on the outside burned off and I can see the metal wound
around the resistor.  I can't read the resistor codes but it reads 182 ohms
cold.  I don't have a schematic and am not sure what the resistor does but
I'm thinking that it could be possible that the resistor may fail open once
it gets hot.  Metcal's site doesn't have any support info on their site, but
I am going to try calling them later.  So, on the off-chance that someone
here might have one of these systems open, can you tell me what the value of
R2 is?  Hopefully this resistor is the fault, but friend of mine who is an
instrument tech at a large electronics company told me that he's never had
to work on any of the MX-500's they have.  One thing he did tell me was that
someone from Metcal told him that if the handpiece cord was crushed (for
example by rolling a chair over the cord) that the coax can form a notch
capacitor which can affect the performance of the tip.  Has anyone here who
has one had this happen?

Regards,
Bob
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