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How to find if the remote control is bad?

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AlainB

Member
Hi,

My friend think that her Sony DVD remote control is not working anymore.

The DVD is working well if you use the commands on the unit itself.

Here is the remote that I am talking about:

SONY AUDIO REMOTE CONTROL Part Number 147655211 Generic RM-U305

Is there a way that I can test if it is the remote that is the problem? I have an oscilloscope and already find out that there is something going on if I touch the probe on any side of the battery and press any button of the remote.

For now, I am there. I can't even open the bloddy thing. I don't find the way.

Any tips on how to open it and/or diagnose if it is working or not would be greately appreciated.

Thanks!

Alain
 

Hero999

Banned
First check the battery.

Then check the waveform across the IR LED, it should emit bursts of about 38kHz squarewaves with an amplitude of about 1.5V. If that works, get an IR transistor connect a 10k resistor in series with it and hook it up to a 5V supply. Set the 'scope to AC coupled, shield the IR transistor from natural light, aim the remote at it and a monitor the waveform across the IR transistor, it should be similar to the LED.
 

PatM

Member
The simplest way is to point the remote into the lens of a digital camera.
If the remote is transmitting when you press a button, the light will be visable on the screen of the camera.
Should look like a flickering light.
PatM
 

AlainB

Member
That is clever! Thanks!



It is working with my cell camera too! And the light is flickering.

She said that she changed the batteries but they were comming from another remote that was working. I will put new batteries and see.

Thanks again!

Alain
 

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HarveyH42

Banned
Make sure the window on the player is clean, and have clear path. Some of my stuff have very narrow angles too, almost need to be straight on. Batteries are likely weak though.
 

unclejed613

Well-Known Member
Most Helpful Member
i've seen the IR sensors in the unit go bad or get gunk in the window from humidifiers. on Sony's there is a little IR icon on the unit where the sensor window is. sometimes customers put stickers on the front of the unit and cover the window. the IR icon is a small white square with the letters IR in it, the sensor window is usually right above the icon. on some home theater systems with the little 2 inch speakers, the IR sensor is in the base of the center speaker, and plugs in to the subwoofer amp with a 1/8" plug. most people think it's in the subwoofer because the FL display is in the subwoofer.
 

AlainB

Member
It is working fine now!

New batteries plus a good cleaning of both the remote control and the DVD unit IR windows fixed the problem.

Alain
 
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