I have a Luxman DC-114 CD player which does not respond to IR commands. The remote control is working correctly. I am having trouble locating a service manual for this manual. Does anybody have info on where I can obtain one? Thanks in advance.
Speaking now as a tech, most (98%) of problems are down to remotes rather than faults in the equipment. That always leaves that 2% or so though, so lets be sure 🙂
Are you 100% sure the remote is OK and that it is the correct one for the player ?
Has it worked the player OK before failing ?
How have you tested the remote to be sure it is OK ?
99% of remote faults are the ceramic resonator (crystal) and open circuit IR diodes.
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If you suspect a player issue then its easy to troubleshoot. The IR receiver should be easily identifiable on the front panel and normally has 3 connections of 5 volts, ground and output. A scope check on the data out will show if the receiver is outputing data (5 volts pk-pk of signal). Try other remotes for other equipment... the data will still be present on the receiver, just not recognised by the unit as valid.
Are you 100% sure the remote is OK and that it is the correct one for the player ?
Has it worked the player OK before failing ?
How have you tested the remote to be sure it is OK ?
99% of remote faults are the ceramic resonator (crystal) and open circuit IR diodes.
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If you suspect a player issue then its easy to troubleshoot. The IR receiver should be easily identifiable on the front panel and normally has 3 connections of 5 volts, ground and output. A scope check on the data out will show if the receiver is outputing data (5 volts pk-pk of signal). Try other remotes for other equipment... the data will still be present on the receiver, just not recognised by the unit as valid.
Yes, I'm sure the remote is working. It is the remote that came with the player when I purchased it back in the 90's I started with the remote first by resoldering the entire board. I scoped the crystal and verified it is oscillating with button presses (f=4MHz or 10MHz, I can't remember). I can see light pulses from the diode using a cell phone camera. I purchased a second remote off ebay with no different results. I opened up the CD player and scoped the IR line back to the main board and can see 5V pulses when remote control buttons are pressed. I just can't seem to figure out where the IR line goes once it gets to the main board.
The IR data normally just goes to the system control IC. You must trace this line back to the IC to make sure the data arrives and that there is no broken print etc anywhere.
It's very rare to find RC issues with the actual unit itself but it does occasionally happen.
I'm not familiar with the Luxman so make sure that there is no small switch anywhere on the unit that selects different remotes (such as using a Luxman amplifier remote to control the player).
Does the player have any kind of backup PSU such as a rechargeable battery or "supercap" to retain any settings. I've never come across just a CD player that does but I suppose there could be one somewhere. If so it's always worth disconecting to reset.
Finally... (and speaking as a tech) the "big IC" is always the very very last suspect so you must make sure everything else is OK before condeming it.
It's also worth (and be very very careful to make sure all PSU caps etc are discharged) pressing a piece of aluminium foil hard over all the leads of the system control IC's to remove all charge. Leave for 24 hours like this. Sometimes uprocessors can get "locked" in odd ways and this resets them by removing all charge. I have had it happen on several occasions.
If all that fails then a new IC is needed... and if that doesn't work then something in all the above has been overlooked.
It's very rare to find RC issues with the actual unit itself but it does occasionally happen.
I'm not familiar with the Luxman so make sure that there is no small switch anywhere on the unit that selects different remotes (such as using a Luxman amplifier remote to control the player).
Does the player have any kind of backup PSU such as a rechargeable battery or "supercap" to retain any settings. I've never come across just a CD player that does but I suppose there could be one somewhere. If so it's always worth disconecting to reset.
Finally... (and speaking as a tech) the "big IC" is always the very very last suspect so you must make sure everything else is OK before condeming it.
It's also worth (and be very very careful to make sure all PSU caps etc are discharged) pressing a piece of aluminium foil hard over all the leads of the system control IC's to remove all charge. Leave for 24 hours like this. Sometimes uprocessors can get "locked" in odd ways and this resets them by removing all charge. I have had it happen on several occasions.
If all that fails then a new IC is needed... and if that doesn't work then something in all the above has been overlooked.
Thanks for the reply. I was able to obtain a service manual w/schematics and now am able to understand the IR circuitry. I did scope the IR input pin on the uC and find that the carrier freq (38KHz) is not being demodulated by the IR receiver. I'm not sure if this is the way it's supposed to be or if it's a failure of the IR receiver. I think that the uC is able to read only the raw data w/o the carrier freq. Of course the IR receiver is discontinued (Sony SBX1610-52) and I have not been able to locate a datasheet for it. So, I will replace the IR receiver with a pin compatible 38KHz IR receiver and see if this works. I'll also check on all the items you suggested in your reply post. Thanks again.
Receivers should be widely available. They are all essentially the same as long as you get the correct carrier frequency. Even then they still usually work OK but with reduced sensitivity.
HIM602V - HERO - PHOTODIODE, IR RECEIVER, VERTICAL | CPC
The signal from the receiver should be a clean data signal when a button is pressed. You shouldn't see any trace of the carrier on the output.
Also check the 5 volt supply at the receiver with the scope to make sure it is clean.
HIM602V - HERO - PHOTODIODE, IR RECEIVER, VERTICAL | CPC
The signal from the receiver should be a clean data signal when a button is pressed. You shouldn't see any trace of the carrier on the output.
Also check the 5 volt supply at the receiver with the scope to make sure it is clean.
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