Pioneer VSX-808RDS IR problems (Was: Testing an I.R. Receiver)

[Old Sparky]

How can these devices be tested with conventional instruments.? I suspect a faulty I.R. receiver in a Pioneer AV rreceiver, and, checking the 3-terminal device out of circuit witha DMM is, to me, inconclusive.  Using one of those Chinese multi-component testers, the device in question, a GP1U27X, reads like two back to back diodes between pins 1(Output) & 3 (Ground), with corresponding diode readings between pins1 & 2 (Vdd) or pins 2 & 3.  The associated remote control checks out OK using an I.R. remote control tester, and the circuit to which the I.R. receiver connects (basically a 2-transistor switch) checks OK, with +5v being supplied to it.  No doubt the easiest way to prove whether the I.R. receiver is faulty is to get and fit a new one, which I may do.  All functions of the VSX-808RDS work, btw, but operating the remcon has no effect whatsoever.

[Terry]

If you have an oscilloscope you can check for an output signal when the transmitter is operated. You can also use any other IR handset you have to confirm the result - it won't operate anything, of course - but should still produce an output.

This will tell you if the IR Rx is functioning or not - if it is, you can start looking further along the signal path for the problem.

[ppppenguin]

Any smartphone camera can "see" the IR from a remote TX. A veryuseful way to check a remote control handset. I wonder if there are any apps that can analyse and decode the signals.

[Old Sparky]

As I mentioned, Jeffrey, the remote is working. I have an I.R. tester, which confirmed that there is an o/p whichever of it's msny buttons is pressed, but the Pioneer Receiver doesn't respond to any commands from the remcon, even though it is otherwise fully operational. I can check the IR receiver from the Pioneer on my 'scope or by substitution with a new GP1U277X IR receiver, but I'm beginning to suspect that the fault is elsewhere in the circuit.

[Alistair D]

The ones I've come across before have an amplifier built in so would need to be powered to get any signal out. You would need to confirm from the schematic but most seem to work from a supply of +5V.

Al

[Refugee]

I bought a component tester after checking that it does what I want and when it arrived it had the same remote receiver in it and on a second read of the data right at the bottom it says remote tester.
It displays the initial signature pulses the remote uses to wake up the set before sending the code for what was pressed.
.

[Mark Hennessy]

Datasheet is here: http://pdf.datasheetcatalog.com/datashee...Xrvwrz.pdf

Yes, 5V. So to test this in isolation, a bench power supply and a 'scope is all you need. Alternatively, leave in situ and put a 'scope between 0V and signal output. It is an integrated circuit, so a Chinese component tester stands no chance of making sense of it.

I don't recall ever finding a faulty one, but anything is possible...

[Murphyv310]

The remote could still be U/S even though its outputting. I've had ceramic resonators going off frequency by quite a margin and then its unreadable by the micro in the unit.

[Old Sparky]

I've tested the receiver - out of circuit, with a DC supply from AA Cells, with the'scope probe connected between the ground and o/p pins, and am seeing very little on the screen , so, Trev, you may be right Now to open the R/C and check those resonators. Come to think of it, I've occasionally changed them in the past.

[Mark Hennessy]

At the risk of stating the obvious, I'd try another remote control before opening up the existing one (risking damaging it in the process). Yes, it might be the fault, but the receiver could be faulty, and also the test setup could also be a problem. Too many variables right now.