I just want to give props where props is due. Last weekend I finally made it to Mang Mario Reyes' place to get my aircon fixed.
We got there a little before 8am expecting to be the first. What do you know there were already six other people ahead of us! So if you're going on a weekend (heck even a weekday), I suggest you go really early. And you've to be patient too, in case you don't get there first. Bring something to read, and go when it isn't raining because your car will be parked just along the street.
Anyway, the diagnosis took a while, since the mechanics were shuffling from one car to the other, but in all we were able to get the car out by 1pm. Instead of replacing the whole thing which would've cost me 20k++ - a plate was just repaired. I was P4,300. I thought it was a fair price so I didn't 'make tawad' given Mang Mario's legendary expertise.
It has been a week and the aircon's still cool and working!

Mang Mario!