A day of sewing disasters!

Yesterday I managed to finish drafting up my Versatile Wrap skirt pattern and cut my fabric.  Today I thought I'd finally get around to sewing up the main panels.  Everything seemed to be in my favour, 2 out of 3 kids were sleeping and the only child awake was fairly happily entertaining himself.  I pinned together two of my panels, dug out the sewing machine from under my desk, blew off the dust and started to set it all up. 

Drafting up the pattern onto lightweight interfacing for future use. A challenge in our small dining room!

Then things started to go wrong - there were some teething problems with threading the machine (was I doing it correctly?) and then the bobbin, the first one I used got all jammed up so I switched back to the one that I used for my last sewing project even though the colour wasn't a match (it was for inside seams so I wasn't too worried).  Then I couldn't get the stitches right, the thread was tangling up on the underside, so I started tweaking some knobs to see if that would help.  It was getting better but with the tension down to "0" it was still too loose on the underside.  I played around and played around but I couldn't get it right.  I started to Google the manual (this machine is a hand-me-down from my Mum and she still has the manual somewhere to be found.) 

Singer 502

Then the baby woke up, she had a good run sleeping for 4 hrs so I couldn't complain.  I forgot to switch off the machine... about half an hour later while I was in the lounge room I heard a noise that sounded like something fell on the floor so I thought I'd just check and to my dismay the machine was smoking!!!!!! Something had blown (hubby says maybe a transformer).  I'm really peeved because I paid $100 for a service last year and the machine has be sitting idle for most of that time.  Anyway, now I'm at a loss as what to do... should I take the machine for repair or just take the plunge and buy a new one (not that I can afford one at the moment anyway).  It's a Singer from the 80s and the repair guy said it was in really good nick since Mum hadn't used it very much.  Still I don't want to find that it'll be one thing after another that needs fixing.  I still don't know how much this sewing hobby is going to interest me (I do tend to go through fads).   What would you do?