Sony no control with remote

[tvtanner]

Hi- i'm working on sony tv model kdl 32l 5000 and everything seems to be working ok except remote. I tried different remotes. No luck. I pulled out sensor panel and checked for voltage on sensor and measured 3.28 volts on one side of infra-red det. But nothing happens when you press any of buttons on remote on any of pins of plug going to the board. I suspect the light detector. Has anyone had any problems with this?

[Andrew F. Ali]

Re: Sony no control with remote

Is the remote sending signal??
Test by turning on an AM/FM radio to the AM band then bring the remote very close to the radio and press the power button and hear if you are betting a series of beeps. If not change the remote batteries and retry. If nothing then carefully open the remote and wipe the carbod contacts on the pad and board with isopropyl alcohol and do adiode check on the infrared diode.

[Agent24]

Re: Sony no control with remote

You can also check the IR is working with a webcam or digital camera.

You may not see any change in voltage on the sensor with just a multimeter, you probably need an oscilloscope.

[martino]

Re: Sony no control with remote

You need to watch this video

http://www.youtube.com/watch?v=imF8_DHUPmU

[tvtanner]

Re: Sony no control with remote

Thanks Martino--Looked at the video and followed diagram. Found shorted cap. right away. Thanks you saved me a lot of work. Having a diagram sure helps.--Sam

[Andrew F. Ali]

Re: Sony no control with remote

Where was this shorted cap found.....Just in case I encounter the same issue... Thanks

[budm]

Re: Sony no control with remote

MLCC (failure mode for MLCC is shorted circuit) 10uF Filter caps (there are two of them, one of them failed) at the VCC pin of the IR receiver module. He removed MLCC and replaced them with electrolytics type.

[tvtanner]

Re: Sony no control with remote

I think the cap. was 9013 located near IR rec. There was 2 10mfd parallel which made 20 mfd. I removed bad one which left 10mfd. worked very good on 10 mfd so I left it that way. I did"nt want to take chance on soldering on that small board.

[tom66]

Re: Sony no control with remote

It is an odd circuit with so many MLCC and resistors, I'm not sure why Sony did it like that.

[Andrew F. Ali]

Re: Sony no control with remote

Thanks for the feedback.....I'll jot that down in my 'tough dog' note book