Hey All,
So I have a Metcal RFG30 power supply that I've purchased because it was knackered. After opening it up, I took some pictures (after staring in marked wonder at the simplicity and straightforwardness of the circuit boards) of the circuit boards and a gratuitous one of the transformer. The unit was stated as being unable to power on, and from the first picture I can see that the R8, R9, and R10 resistors are burned out.
I've read the thread
https://www.eevblog.com/forum/projects/broken-metcal-rfg-30-soldering-base-unit-fixed/ and I also have located the thread
https://www.eevblog.com/forum/projects/diy-metcal-13-56-mhz-rf-supply/.As such, I have the Metcal MX-500 schematic, and what's listed as values for those resistors are R8 = 3K3 and R9, R10 = 4K7 5% Carbon Film resistor.
Now, I can blindly replace the parts but I was wondering if someone could help me identify what may have caused the damage shown in the first picture? I don't happen to have a scope handy, nor to I have a handle for testing (looking for a deal on ebay) so I'm restricted to my cheap multimeter for time being.
Besides the resistors, what should I consider replacing while I'm at it? For any general jellybean stuff I'm going to grab from Tayda Electronics as I think that everyone has raided all the resistors from Radio Shack, and I can't remember if they carried 5% ones anyway.
Thanks for any assistance and thanks to all that have posted before. Thanks to the DIY thread, I know all the options for finding a new handpiece if it comes down to it. If I have to purchase new, I'll probably go with Hakko's handpiece, although there are a bunch of used tips that are still in great condition available for Metcal's MX-RM3E.




