1.go to sstationary shop to get new refill
2.check the refill by scribling on a paper
if properly writing purchase or ask for new one
3.remove the old refill from the pen
4.inset the neww refill into the pen to start writing

hi nice qs asked,

be smart enough while answering this qs. 
u start of my telling, first u start of with assupmtions 
w.r.to brand of refil, color etc.., den later check for its 
respective features(Brand features - viz renold - renold 
name on refil, )
usuability features, 
functionality and lastly durability.
you cannot do security checking for this.

regds,
swati.

1.Goto stationary shop and bring good refill ball pen.
2.test usability testing
3.verify the pen is writing or not
4.verify how many possibilities we use the pen
This is the test case for pen

Test the dimensions of the pen.
Test the quantity of the ink in the refill.
Test its usebality.
Test the brand.
test the color.
test whether the ink can be refilled or not.
test for the material.
test under what temperatures does it work.
like this the list goes on if u can think better......

Whether there is any leakage of ink in different 
environments like hot,cool,water etc
Is it comfortable to write(like grip)
Whether it is writing smoothly
Whether it is durable,check by droping from certain height
Whether all parts are fitted correctly
like that there can be many test cases

Test cases on refill ball pen:

1)First check the refill is filled with ink or not.
2)Then check pointer or nib of the refill because of smooth
hand writing.
3)Then check the Particular refill should be fit in the pen
or  not.
4)And lastly u must check after u place the refill in pen
then close the refill with cap because of security .

First of all check the basic functionality
1.check whether it is easy to write in paper.
2.check whether it is user friendly to hold the pen and write.
3.check whether is there any overflow of ink while writing.
4.check whether it is writing in hard surface.
5.check whether it is  easy while after changing the refill
 these are the basic..we can add so many like
color,structure,apperanace and so on..if anything wrong in
this..forgive me

It should be in 4 points,Hence according to me the four 
major things are :

1)Quality of ink : overflow of the ink or whether getting 
struck at the middle..
2)Look and feel of the pen : how attractive it is 
color,size etc
3)Reliability : It should give the same smooth writing from 
the begining till the last drop of the ink
4)Grip of the pen : Whether it is soft to hold and write 
for a long time.
Thanks in Regards,
Lakshmmi :-)

Hi 

i guess going to the shop will not be a valid test case for 
this scenario.

 1)Verify the quality of the ink
 2)Verify the usanblity, how ease to write
 3)Verify whether you can refill the pen
 4)Verify the quality of the pen(Easy to break) etc