Anyone know of a decent handyman to fix a fridge in the Petchaburi road/Thong lo area?

If it is not too old and a proper brand like SAMSUNG or ELECTROLUX, those have their own services, i.e. SAMSUNG has a service center at Silom Rd. but they come as well if you call them. I recall they charge 500 THB for coming only. So if it is an older fridge and normal size, you better buy new one for 5k at BigC or Tesco...

Look for a local shop with used refrigerators for sale and they will have someone experienced in such repair - some air conditioner people are also able to repair simple units. But if expensive new type model probably best to have factory techs visit as some can be very complex electronically these days.