hi,my keyboard wont type the letters a,d,l,k and h.as of now i am using on screen keyboard.it's so disturbing. what can i do t

Solution
+1^ Nukemaster
I brought my IBM clickety keyboard back to life with a good cleaning. But be careful, some keyboards are so poorly assembled it is darn near impossible to take them apart and clean them... and get them back together again.
If it is a desktop keyboard. Open it up and try to clean it. Since it works in a grid type fashion, a contact issue in one place can mess up many keys.

For instance, dirt caused my SHIFT to not work with almost my entire top qwertyuiop row. Quick clean and it all works good again.
 
+1^ Nukemaster
I brought my IBM clickety keyboard back to life with a good cleaning. But be careful, some keyboards are so poorly assembled it is darn near impossible to take them apart and clean them... and get them back together again.
 
Solution
I take out the board and cheap bubble contact part and toss the rest into the sink to clean it for sure. Never used the actual dishwasher for it 😛