How do I troubleshoot my IR Blaster (Samsung Galaxy Tab 4) I've had my Samsung Galaxy Tab 4 for many years now and I have occasionally used the built-in "IR Blaster" with the Peel Remote app.  Now I have a more pressing need to use this, I found that the Peel app no longer shows any remote configured, and when I go to set it up, the only options offered are to connect to a ROKU device via bluetooth or to setup a 'Pronto' external IR Blaster device. This tells me that Peel no longer 'sees' the internal IR circuit. 

I compared this to my Samsung S5 phone which also has an IR blaster built in.  Peel Remote app on the phone correctly sees the IR Blaster, and will change channels, etc.   On my proven Samsung S5 phone, I downloaded a simple 'remote control' app called ASMART Remote IR, which I then configured it to control my Vizio TV.  Worked. I downloaded the same App onto the tablet and it failed to work (no error messages, just failed to work). 

I figured some combo of apps / settings had messed up the tablet so did a factory reset, and chose NOT to restore any prior apps or data - a totally clean start.  On this clean tablet, I then installed Peel again; but again, it did not 'see' the local IR blaster, and offered to setup a Pronto device (which is a 3rd party IR Blaster). I also re-downloaded the ASMART app, and it also failed to work.  

So I'm baffled as to what could have happened (other than the IR blaster circuit is dead). 

Anyone have any thoughts?  Thanks! 

Edit To Add: looks like the Android 5 (lollipop) upgrade from Samsung removed support for the IR blaster. So I may have to downgrade to Kit-Kat (Android 4). Darn. There's some suggestion out there that this can be made to work, but I haven't figured it out yet. I guess it's time to get a standalone IR device that talks to the phone wirelessly.
In galaxy S5, we can use *#0*# to open the Hardware module test app. So I guess it needs to work for your galaxy tab 4. If it works, then click on the IR module to test it.