After repeated unplugging toslink input on dac pcb it is intermittently noisy on one channel until wobbled then will work for a while. Physical connection with all cables is now qoute loose. Looks cheap. Is better with some cables than others. Already had to epoxy it to board to secure it when new as it is so flimsy. Are these things replaceable and electronically standard? Most irritating. Please help.
Thanks in advance.
Thanks in advance.
Sorry, Seems odd it only effects one channel. It is one ldr for both channels information after all. 😕
Have you reflowed the Toslink receiver's connection points?
When the connector loosens, the joints can crack, or the traces micro-fracture from physical stress.
The ones here have five pins arranged in a 2x3 grid - the first two appear to be for mechanical support - the three back pins are VCC, ground, and signal out with VCC the rightmost pin as you look at the connector.
It may be that your device has separate decode for each channel and that one channel's trace has broken.
Cheers
Jim
When the connector loosens, the joints can crack, or the traces micro-fracture from physical stress.
The ones here have five pins arranged in a 2x3 grid - the first two appear to be for mechanical support - the three back pins are VCC, ground, and signal out with VCC the rightmost pin as you look at the connector.
It may be that your device has separate decode for each channel and that one channel's trace has broken.
Cheers
Jim
As OP suggests, an input fault can't affect just one channel consistently. It's most likely that wiggling the toslink is merely causing a make/break of a bad solder joint(s) elsewhere on the board.
Thank you.
You are both correct as problem is identical if using coax input,cured briefly with a wobble of dac or inputs. No visible breaks, going to be an adventure finding problem as it is intermittent.
Are the through board connections the most likely to fail in this way? (2 layered board) is it pos. to reinforce these?
In all my future projects, connections to the outside world ( mine is teeming with wild children) will be firmly chassis mounted. Lesson learned.
Thanks again.
You are both correct as problem is identical if using coax input,cured briefly with a wobble of dac or inputs. No visible breaks, going to be an adventure finding problem as it is intermittent.
Are the through board connections the most likely to fail in this way? (2 layered board) is it pos. to reinforce these?
In all my future projects, connections to the outside world ( mine is teeming with wild children) will be firmly chassis mounted. Lesson learned.
Thanks again.
Hmmm - different kettle 'o fish if both inputs are noisy - not sure how your DAC handles switching between coax and Toslink, but the ones I've been playing with (and receiving quite an 'education' about, see here:http://www.diyaudio.com/forums/digital-line-level/272098-s-pdif-problems-muse-mini-pcm-1793-dac.html) use a hex inverter as a switch/buffer ahead of the digital receiver chip.
The common points of failure here would be the switching chip's VCC (pay attention to any through-hole decoupling caps and reflow all joints), its ground, and the output to the digital receiver chip.
Silly question - when you say "wobble the dac..." do you mean the whole blessed device or just the DAC chip?
If you haven't already opened the box & had a poke around recently, not a bad idea - with Young 'Uns on the loose all sorts of odd cruft finds its grubby way into HiFi components & sugary glorp can be remarkably conductive where you really don't want it.
For discovering and squashing physical connection gremlins, my weapon of choice is wooden cooking chopstick - they're not quite as pointy as a table 'stick, and allow you to apply a fairly localized jolt to suspect connections with little shorting or damage risk.
Cheers & good luck ...
Jim
The common points of failure here would be the switching chip's VCC (pay attention to any through-hole decoupling caps and reflow all joints), its ground, and the output to the digital receiver chip.
Silly question - when you say "wobble the dac..." do you mean the whole blessed device or just the DAC chip?
If you haven't already opened the box & had a poke around recently, not a bad idea - with Young 'Uns on the loose all sorts of odd cruft finds its grubby way into HiFi components & sugary glorp can be remarkably conductive where you really don't want it.
For discovering and squashing physical connection gremlins, my weapon of choice is wooden cooking chopstick - they're not quite as pointy as a table 'stick, and allow you to apply a fairly localized jolt to suspect connections with little shorting or damage risk.
Cheers & good luck ...
Jim
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