Hi All,
I'm looking at a CYRUS CD8x which has no SPDIF O/P.
The Ananlogue works fine.
I can't find a circuit anywhere but as far as I can make out it is a AK4103AVF which performs the task of producing the SPDIF in this Player.
Datasheet here.........
AK4103AVF pdf, AK4103AVF description, AK4103AVF datasheets, AK4103AVF view ::: ALLDATASHEET :::
The chip has it's supplies and I can 'scope the MCK, BCK, LRCK & DATA entering it but no SPDIF O/P is produced.
As far as I can tell, though I hope to be proved wrong, there is no way of turning On & Off the SPDIF O/P either via the Front Panel or the Remote.
I have replaced the AK4103AVF but the fault remains.
Does someone know if the SPDIF can be turned On & Off on this Player? If so may I ask how this is performed?
Has someone come across this fault previously on this Player?
Any thoughts at all appreciated.
P.
I'm looking at a CYRUS CD8x which has no SPDIF O/P.
The Ananlogue works fine.
I can't find a circuit anywhere but as far as I can make out it is a AK4103AVF which performs the task of producing the SPDIF in this Player.
Datasheet here.........
AK4103AVF pdf, AK4103AVF description, AK4103AVF datasheets, AK4103AVF view ::: ALLDATASHEET :::
The chip has it's supplies and I can 'scope the MCK, BCK, LRCK & DATA entering it but no SPDIF O/P is produced.
As far as I can tell, though I hope to be proved wrong, there is no way of turning On & Off the SPDIF O/P either via the Front Panel or the Remote.
I have replaced the AK4103AVF but the fault remains.
Does someone know if the SPDIF can be turned On & Off on this Player? If so may I ask how this is performed?
Has someone come across this fault previously on this Player?
Any thoughts at all appreciated.
P.
Goes 'High' on first application of the Mains.
I have to say, strangely enough, remains High even when the unit is turned in to Standby.
Unfortunately, without a circuit I don't know where this is derived from. I am assuming the Main Micro (?). With the rest of the unit 'working' I had assumed (do you think incorrectly) that the Reset was OK.
P.
I can't 'scope it on Pin 19 or 20 of the chip though. And no, there's no shorts to 0 Volts.
I will check for continuity from the chip to the Output Sockets, Toslink & RCA though to be 100%
P.
As far as I can see..................(without a Schematic, but I have measured DC resistences where I can. But when the tracks disappear under IC's etc etc .... !!!!) the same DATA, LRCK and BCK lines feed the internal DAC's which are working.
(I appreciate your perseverence with this with me !!)
P.
That's great, thanks.
From memory (I'm not in front of it at the moment) that looks really similar.
And the circuit around the AK4103 is pretty simple. So what am I missing ? !!!! I need to have a good think about it !!!! It must be something really obvious I'm just not seeing.
Cheers,
P.
From memory (I'm not in front of it at the moment) that looks really similar.
And the circuit around the AK4103 is pretty simple. So what am I missing ? !!!! I need to have a good think about it !!!! It must be something really obvious I'm just not seeing.
Cheers,
P.
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OK, I have been checking my soldering and the voltages on the pins of the AK4103 I replaced.
All soldering OK.
But, and I'm not particularly proud of this but while checking the Voltages on the IC I inadvertantly shorted out Pins 15 & 16.
Pin 15 is tied to DGND and Pin 16 is tied to +5VCD
Now, I cannot explain why and I don't want to do it too many times as it's bad practice and not good for the 5 Volt Supply but, it will do it every time, shorting out these Pins obviously turns the Player into Standby but, it turns ON the SPDIF. If the Player is then turned out of Standby it reads the Disc and then if asked to Play does so and the Output from the SPDIF produces output from a DAC.
The Player can be turned into Standby and then ON again and the SPDIF remains. This is mainly due to the +5VCD not turning off when the Player is put into Standby.
But if the Mains is removed, the SPDIF will also disappear and not return.
There is no Reset on the AK4103. As far as I can tell, the +5VCD is not designed to appear after a delay of any kind.
Any thoughts or help would be appreciated as this is driving me nuts now.
P.
All soldering OK.
But, and I'm not particularly proud of this but while checking the Voltages on the IC I inadvertantly shorted out Pins 15 & 16.
Pin 15 is tied to DGND and Pin 16 is tied to +5VCD
Now, I cannot explain why and I don't want to do it too many times as it's bad practice and not good for the 5 Volt Supply but, it will do it every time, shorting out these Pins obviously turns the Player into Standby but, it turns ON the SPDIF. If the Player is then turned out of Standby it reads the Disc and then if asked to Play does so and the Output from the SPDIF produces output from a DAC.
The Player can be turned into Standby and then ON again and the SPDIF remains. This is mainly due to the +5VCD not turning off when the Player is put into Standby.
But if the Mains is removed, the SPDIF will also disappear and not return.
There is no Reset on the AK4103. As far as I can tell, the +5VCD is not designed to appear after a delay of any kind.
Any thoughts or help would be appreciated as this is driving me nuts now.
P.
But basically all I'm doing is shorting the +5VCD to 0 volts.
Why would this generate a Reset for the chip? That should happen then every time the Mains is applied and the 5 Volts appears ?
I think you're right about the PDN Pin though, I think this is where the fault must lie. Why would they not tie it to +5VCD if they just intended it to sit at +5V the whole time, even in STDBY? This should be dropping to 0V when the set goes into STDBY I think.
I will take another look.
Thanks for your suggestions so far, much appreciated. Two heads better than one and all that.
P.
Pins 15 and 16 are the the clock select pins. Any change to them that exceeds 3 MCLK cyles generates an internal reset. Shorting them changes them from 1,0 to 0,0 , changing the selected MCLK frequency and back again, enough to generate a reset.
Tying PDN permanently high would defeat the pins function as the power on reset pin. It needs to transition from low to high at power-on to initialise the chip. The image below is from the AKD4103 evaluation board.
Tying PDN permanently high would defeat the pins function as the power on reset pin. It needs to transition from low to high at power-on to initialise the chip. The image below is from the AKD4103 evaluation board.
Attachments
It looks like in the CD6/8 the PDN Signal is derived straight from Pin 20 of the Main Micro.
There's an internal Pull-Up Resistor within the AK4103 so a straight connection to the Micro. A bit of broken track or a dry on the Micro might be my trouble?
I'll take a look at what's happening there when I next get the chance.
Thanks again,
P.
There's an internal Pull-Up Resistor within the AK4103 so a straight connection to the Micro. A bit of broken track or a dry on the Micro might be my trouble?
I'll take a look at what's happening there when I next get the chance.
Thanks again,
P.
Checked for broken Track between the Micro and the AK4103, all OK.
The PDN Signal is derived from the Micro's /STANDBY Pin, PIN 20. This remains at +5V at all times. Even though the Player itself switches into Standby (Display OFF etc) when asked to do so.
It's a 'bodge', but if a 47uF is placed across the PDN Pin and 0V then the charging time for the cap allows the PDN Pin to become +5V with such a delay as to allow he AK4103 to 'turn ON' and therefore the SPDIF appears. It never turns off though even when the Player goes into Standby. But then the +5VCD doesn't disappear either (?).
I wondered about the Reset IC, IC508 so replaced this but still the same.
Main Micro ? I doubt I'd get one of these now. Would have to send the Player to Cyrus for repair @ ££ God knows !!!
It's 'working' now but it is a bodge of a repair and my curiosity would like to know what's going on.
Any thoughts rfbrw?
Cheers,
P.
The PDN Signal is derived from the Micro's /STANDBY Pin, PIN 20. This remains at +5V at all times. Even though the Player itself switches into Standby (Display OFF etc) when asked to do so.
It's a 'bodge', but if a 47uF is placed across the PDN Pin and 0V then the charging time for the cap allows the PDN Pin to become +5V with such a delay as to allow he AK4103 to 'turn ON' and therefore the SPDIF appears. It never turns off though even when the Player goes into Standby. But then the +5VCD doesn't disappear either (?).
I wondered about the Reset IC, IC508 so replaced this but still the same.
Main Micro ? I doubt I'd get one of these now. Would have to send the Player to Cyrus for repair @ ££ God knows !!!
It's 'working' now but it is a bodge of a repair and my curiosity would like to know what's going on.
Any thoughts rfbrw?
Cheers,
P.
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