RM-F04 remote not working

Huge thanks to everyone for their input on this - it's really appreciate, and very interesting to read the developing thoughts.

I'm not going to have time to look in to this for a while, so will pick it up probably next week or so.

I'm considering trying out replacing the cap first as that seems to be more likely, and probably easier to start with.

I think i've had this HDR from new since about 2011 or so - therefore the components are getting on a bit I guess.
 
Stummery said:
You may be correct.

I have just checked the circuit, the sensor is powered from the 5v supply via a 100 ohm resistor and decoupled by a 47uF capacitor, if the capacitance value reduced it could cause these symptoms.
The fact that aod said "Thinking about it, the remote does seem to have been getting less responsive over the last few years" could be another clue.

Checking the in-circuit ESR reading on mine = 8 ohms this is poor for a 47uF and does, as BH suggests, lead to it being another suspect capacitor and a possible source of problems and would be worthwhile replacing first.


Edit: In the datasheet for the IR receiver the recommended capacitor value is 100uF.
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Please can someone link me to a suitable capacitor I can order for this please? UK based.
 
aod said:
Please can someone link me to a suitable capacitor I can order for this please? UK based.
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They're cheap in bulk; individually you're pretty much paying for delivery. PM me your address and I'll send you a suitable 100uF capacitor (or 47uF if you would prefer to stick with OEM – but the datasheet spec says 100uF so Humax were on shaky ground).
 
I'm pretty certain the wrong tree is being barked up here.

I've used many of these devices with a 100R/10u combination on the supply with no problems even in one application where an undocumented property of the IR Rx was being used.

This thread has prompted me to pull the DTR-T1000 out of the loft so I could swap its front panel onto the main HDR whose blue LEDs have faded to the point of uselessness.
I had wondered if they'd used the programmable input pull-up resistor on the AVR ATmega164 but there's a 2k7 pullup on the Rx's open collector output. I'd use >=10k but it shouldn't be a problem.

It would be easy enough to check the output of the Rx with a 'scope but not everyone has one. An alternative would be a small piezo sounder, one without driver electrics, which would at least give some indication of it working or not.

I'm still going with it having the signs of the IR Rx being swamped by another source of pulsed IR, although this doesn't explain the TV apparently being OK.
 
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everthewatcher said:
I'm pretty certain the wrong tree is being barked up here.

I've used many of these devices with a 100R/10u combination on the supply with no problems even in one application where an undocumented property of the IR Rx was being used.

This thread has prompted me to pull the DTR-T1000 out of the loft so I could swap its front panel onto the main HDR whose blue LEDs have faded to the point of uselessness.
I had wondered if they'd used the programmable input pull-up resistor on the AVR ATmega164 but there's a 2k7 pullup on the Rx's open collector output. I'd use >=10k but it shouldn't be a problem.

It would be easy enough to check the output of the Rx with a 'scope but not everyone has one. An alternative would be a small piezo sounder, one without driver electrics, which would at lease give some indication of it working or not.

I'm still going with it having the signs of the IR Rx being swamped by another source of pulsed IR, although this doesn't explain the TV apparently being OK.
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We might have some very decent tree surgeons here!

I have the remote working now, but it could be a combination of things that have helped.

1. It's been powered off for about 1 week
2. I did have a switchbot hub mini set up
3. There was 1 other remote control in line of the Humax.

I have since plugged the switchbot hub back in and the remote still works. I've only had this for about 2 months.

I'll monitor and see how it goes, if it fades over time I'll try removing the hub and other remotes to see what happens.

There's a chance the capacitor might still be on the way out maybe, but we'll see.

Thanks again!
 
everthewatcher said:
I had wondered if they'd used the programmable input pull-up resistor on the AVR ATmega164
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My HDR Fox T2 has an ATmega 324_PA on the front panel.

Checking for IR swamping is a simple process, just move the unit to another location or even make a shield with a cardboard box/tube.
 
Stummery said:
My HDR Fox T2 has an ATmega 324_PA on the front panel.
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Same device but double the memory across the board. Didn't note which one I read it off but both PCBs were '12 production within a couple of months.
[Edit] It's a '164 on both.

Stummery said:
Checking for IR swamping is a simple process, just move the unit to another location or even make a shield with a cardboard box/tube.
Click to expand...
That's what I suggested back in my #17.
 
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