Agree with BH. To add my experience. I have 4 HDRs that have been using various cheap RT3070 dongles for many years without any problems.
Maybe OS is not as good with hardware as they assume :laugh:
Since my previous post I have, in the simulation, placed a variable resistor in parallel with the 4.7uF capacitor and it needs setting to a value of less than 400 ohms before it starts to reduce the output voltage, less than 350 ohms before the output voltage drops below 10 volts and 330 ohms...
If anyone is interested and has any thoughts/comments I have copied the circuit in to Proteus simulation software. As expected without the 4.7uF capacitor the switching is more or less instantaneous.
I include the oscilloscope traces for switch on and off of the HDD control, that is 5v and 0v...
Heres a thought. You are obviously not going to get your questions answered.
So why don't you buy and fit one...... then you can answer all your questions and provide valuable feed back to the rest of the forum.
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.
Correct, that is why the EDS-88A does a low voltage DC resistance test first. As you say capacitors and other components can fail low resistance/short circuit as well.
I use an EDS-88A CapAnalyzer (from USA) that is designed for in-circuit capacitor ESR testing and uses less than 50 millivolts.
As you can see a 47uF ESR at 8 ohms is well into the red part of the chart! So I shall be replacing mine.
Edit: Measuring my capacitor value out of circuit reads 26uF...
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...
In that case you could try fitting a new sensor. They are readily available from Ebay (from £1.30 including post UK seller).
You need a VS1838/TL1838 this has the correct pin out.
@BucksLad Tried to DM but I think you have it turned off.
If you have no other takers I could use it for spares - but it would need to be posted as I am in Devon.
As long as someone is at home I believe Hermes will collect - or it can be dropped off at lots of stores/places.
I would be happy to...
I carried out an in-circuit ESR check on all the silver SMD electrolytics in my 3 boxes when this problem was discovered. All of the other capacitors checked as OK with low ESR readings apart from the 3x 4u7 capacitors, which read 6, 6 and 8 ohms. As standard 4u7 25v capacitors (not low ESR)...
From personal experience, with power supply PCBs etc, the capacitor I have ringed in red is also suspect as I have had many of this type go either open or leaky.
Comparing my graph to the readings taken by BH I have managed a reduction of over 30°C
A dedicated fan is the easiest way to obtain the lower temperature without a noticable increase in noise, my SoC fan is barely audible even with the lid removed.
Unlike the BH modification my SoC fan is...
Agree with BH. To add my experience. I have 4 HDRs that have been using various cheap RT3070 dongles for many years without any problems.
Maybe OS is not as good with hardware as they assume :laugh:
Since my previous post I have, in the simulation, placed a variable resistor in parallel with the 4.7uF capacitor and it needs setting to a value of less than 400 ohms before it starts to reduce the output voltage, less than 350 ohms before the output voltage drops below 10 volts and 330 ohms...
If anyone is interested and has any thoughts/comments I have copied the circuit in to Proteus simulation software. As expected without the 4.7uF capacitor the switching is more or less instantaneous.
I include the oscilloscope traces for switch on and off of the HDD control, that is 5v and 0v...
Heres a thought. You are obviously not going to get your questions answered.
So why don't you buy and fit one...... then you can answer all your questions and provide valuable feed back to the rest of the forum.
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.
Correct, that is why the EDS-88A does a low voltage DC resistance test first. As you say capacitors and other components can fail low resistance/short circuit as well.
I use an EDS-88A CapAnalyzer (from USA) that is designed for in-circuit capacitor ESR testing and uses less than 50 millivolts.
As you can see a 47uF ESR at 8 ohms is well into the red part of the chart! So I shall be replacing mine.
Edit: Measuring my capacitor value out of circuit reads 26uF...
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...
In that case you could try fitting a new sensor. They are readily available from Ebay (from £1.30 including post UK seller).
You need a VS1838/TL1838 this has the correct pin out.
@BucksLad Tried to DM but I think you have it turned off.
If you have no other takers I could use it for spares - but it would need to be posted as I am in Devon.
As long as someone is at home I believe Hermes will collect - or it can be dropped off at lots of stores/places.
I would be happy to...
I carried out an in-circuit ESR check on all the silver SMD electrolytics in my 3 boxes when this problem was discovered. All of the other capacitors checked as OK with low ESR readings apart from the 3x 4u7 capacitors, which read 6, 6 and 8 ohms. As standard 4u7 25v capacitors (not low ESR)...
From personal experience, with power supply PCBs etc, the capacitor I have ringed in red is also suspect as I have had many of this type go either open or leaky.
Comparing my graph to the readings taken by BH I have managed a reduction of over 30°C
A dedicated fan is the easiest way to obtain the lower temperature without a noticable increase in noise, my SoC fan is barely audible even with the lid removed.
Unlike the BH modification my SoC fan is...
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