Here is the simplest ir remote tester circuit which is completly made of general components like led , photododes and battery. It works just as any complex ir remote testing circuit with transistors and ir recievers. To test any remote you have to bring the remote close to the photodiode (atleast 7cms or closer) and press any button, then the led will start glowing as per the frequency of the remote's output and hence you will come to know that you remote is working and if it does not gives that flash then you remote is out of order.

Step 1: Parts

There are very few parts which are used in this circuit.They are:

250 OHM resistor *
3v Battery
Photo diode
LED
Photodiode covering.*
Switch*

Here * means optional. But photo diode covering is also pre fered you can use and translusent medium.

Step 2: Circuit & Making

Here is a small circuit diagram form 123D designing tool. The PCB foil is also given,(Scroll up putting your pointer over the circuit to zoom in and ignore the alone resistor at the right side. )

Now once you have made this circuit you have to do another job which is to put a traslusent covering on the photodiode so it won't catch too much light (You can stick it to the covering with hot glue or any transparent glue) , And then go with the casing. Now you are finished. Try some old remotes on it.