Repairing a bricked Karbonn A9+/Cherrymobile S100

As you can see the cherrymobile logo while booting your device, so it is a softbrick and can be recovered by flashing original or Custom ROMs. Now, as you told above, I can make out the problem is with you Karbonn A9+ drivers. Try to check if your device is being properly detected while connecting it to PC. For doing so, connect your Karbonn A9+ to PC via USB cable. Now, press and hold volume up key and power key so as to enter Fastboot mode. Now when the Fastboot logo appears on your device, just right click on "My Computer" and select "Manage". Now click "Device Manager". If you see an exclamatory sign (in yellow) on any of your drivers (probably the device drivers), then you need to first fix this problem.

To fix this, you need to first download ADB drivers from here:
http://androidxda.com/download-best-android-adb-driver

Now extract these drivers and install them on your PC. Now head back again to "Device Manager" and right click the driver which is marked exclamatory (in yellow). Then click "update driver software" and then select "browse my computer for drivers". Now select the adb driver which you downloaded and click next to apply the changes.

Now, disconnect and then reconnect your Karbonn A9+ to your PC and enter the Fastboot mode. Now, you can flash the official or any custom ROM for your device without being getting into any errors. However, I recommend you to download and flash the official firmware.