This window had been broken for a while, in the sense it would not slide up or stay up when opened. After researching on how windows works and the various parts of a window and their functions, I found out that the spring balances had dislocated from their locations in the window jamb which is why the window would not open or stay open.
While examining the window sash, noticed that the right window tilt lock also had cracked. I got the following replacement from home depot. I had to file off some plastic of the side so that the piece slide in the slot on the sash easily.
After removing the sash from the window, examined the 2 spring balances. They had worn out, had rusted so decided to replace them.
Replacements were not easily available. Found them on only one site, SWISCO.com which were eventually the perfect fit.
Now insert the spring balance in the window jamb. Insert it on the edge and then twist it in by 90 degrees so that it fits in the window jamb.
Lock the spring into a position by turning the “U” shaped piece at the bottom of the spring using a flat head screwdriver. “U” facing up means unlocked and once turned by 90 degrees, means unlocked.
At the top of spring is a hook to be screwed into the window jamb. I used the same holes from before, but introduced an “O” ring, metal washer, for a snug fit. Used 1″ kreg screws.
Once the screw is in place, loosen the “U” shaped piece and pull the spring down to a level easy to latch the sash back in. Once it is at a comfortable level (around 6″ to 8″ from the bottom of the window) tighten it and insert the window sash back in place. Make sure the window tilt locks snap into place and the window can slide up and down easily.