Defect in an Item

Q: Zaid bought a device from Amar. When Zaid received it he switched it on and it gave a firmware error. (Firmware is a term sometimes used to denote the fixed, usually rather small, programs that internally control various electronic devices. Firmware is always involved with very basic low-level operations in a device, without which the device would be completely non-functional.) Zaid informed Amar of the error message but then it no longer gave the error. However, a short while later the same error occurs. Now the device is rendered totally unusable. Zaid has not yet paid for the device. What is the ruling in this matter?
Can he return it? Is Amar obliged to accept it considering that the error had recurred and was not new? If Zaid has to pay for the repair can he claim from Amar or deduct from the price?

A: The error in that device will be considered a defect in the item. The ruling for defects discovered after the sale is that the buyer can return it for a full refund, or keep it and use as is. But he cannot deduct any sum from the purchase price.
The fact that the error did not recur for a while makes no difference, as long as the initial error was pointed out to the seller. The reason for this is that modern-day electronic devices tend to malfunction at various intervals, and in this case the device has been rendered unusable. This is a valid reason for seeking a refund. Zaid may return it without owing anything. If he decides to keep it, he must pay the full price.