Hi,
I have this TV a small 20 inch that works perfectly except for the IR has stopped. I have confirmed that the remote control is fine and tried an alternative and even tried with IR blaster from phone. Remote 100% ok.
Tried installing latest firmware but no change.
TV won't respond to remote at all, not even to bring it out of standby. I have to use the touch sensitive front panel to operate, at which point TV is usable albeit with no remote.
Tried replacing the IR receiver diode/bulb on front panel and no change so put the old one back. After tracing the circuit a little I found that the SIGNAL line of the IR receiver board (and bulb) is always LOW (less than half a volt). I think i'm right in thinking that this line should be 3.3v all the time until you press a button on the remote. At least this is how it's always worked when i've played with IR on an Arduino!
Traced the line further onto mainboard and it goes into a WELTREND IC (microcontroller?). No bad SMD caps or open resistors. Seems like issue with WELTREND IC? Incidentally, the other lines on the IR receiver (GND and 3.3V) are present. I measured the SIGNAL line with Oscilloscope while pressing remote and could see a square wave IR code but extremely low voltage (like half a volt or less). So seems like the issue is with the voltage being pulled down on the signal from sub micom?
I'm not sure if doing a standard USB firmware update would also update the sub micom, maybe someone can confirm? If it does then perhaps the IC itself is bad because I initially thought it might be corrupted. I seem to recall having a Samsung one time that needed to have the sub micom chip reflashed to fix this kind of issue. Wondering if anyone has experienced this or even has a copy of the firmware for this IC? or any advice in general?
Many thanks,
James.
I have this TV a small 20 inch that works perfectly except for the IR has stopped. I have confirmed that the remote control is fine and tried an alternative and even tried with IR blaster from phone. Remote 100% ok.
Tried installing latest firmware but no change.
TV won't respond to remote at all, not even to bring it out of standby. I have to use the touch sensitive front panel to operate, at which point TV is usable albeit with no remote.
Tried replacing the IR receiver diode/bulb on front panel and no change so put the old one back. After tracing the circuit a little I found that the SIGNAL line of the IR receiver board (and bulb) is always LOW (less than half a volt). I think i'm right in thinking that this line should be 3.3v all the time until you press a button on the remote. At least this is how it's always worked when i've played with IR on an Arduino!
Traced the line further onto mainboard and it goes into a WELTREND IC (microcontroller?). No bad SMD caps or open resistors. Seems like issue with WELTREND IC? Incidentally, the other lines on the IR receiver (GND and 3.3V) are present. I measured the SIGNAL line with Oscilloscope while pressing remote and could see a square wave IR code but extremely low voltage (like half a volt or less). So seems like the issue is with the voltage being pulled down on the signal from sub micom?
I'm not sure if doing a standard USB firmware update would also update the sub micom, maybe someone can confirm? If it does then perhaps the IC itself is bad because I initially thought it might be corrupted. I seem to recall having a Samsung one time that needed to have the sub micom chip reflashed to fix this kind of issue. Wondering if anyone has experienced this or even has a copy of the firmware for this IC? or any advice in general?
Many thanks,
James.
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