Electrónica Nacional is one two places I know of to get all of your electronic appliances repaired. They used to be located to the right of the MoviStar office (which has now moved to Plaza El Terronal). I have had items repaired at both of these stores.
I was out this morning and happened to see the new location. It is located off Ave. Obaldia on a side street just past the Conase Insurance Office. If you are driving on Ave. Obaldia, toward down town, turn right at the corner past Conase.
On your left you see this sign. This photo was taken looking toward Conase. Here is a Google Map to Electronica Nacional.
This is a photo of Electrónica Nacional. You will see it to the right of Hondas Chiricanas.