24 I/O works after "cold" start, but then sample rate starts flashing endlessly
Posted: Wed Dec 13, 2023 4:32 pm
I have a 24 I/O rack unit hooked to a PCIX-424 card.
When I first turn the unit on, the sample rate indicators do their normal "scan" before eventually settling on a single rate, which remains solidly lit (for example, "44.1", or whatever was last configured). I can then also configure the unit to switch to any of the four available rates, as normal.
However, after the unit has been on a little while (just minutes) the sample rate indicator will suddenly start flashing by itself and then never stops, no matter what I do. (The unit is set to use the internal clock of the PCI-424, so this is not due to a missing clock signal.)
Once in this "endless flashing" state, the unit is still detected by the computer (PCI Audio Setup can see it, with no error messages) and the unit still responds to sample rate configuration changes (in a way) but the sample rate indicator never stops flashing. Curiously, attempting to set the rate to either 44.1 or 48 always makes the unit switch to flashing only 44.1. Likewise, attempting to set the rate to 88.2 or 96 always makes the unit switch to flashing only 88.2.
Now, I have three other 24 I/O rack units which are working fine with the same PCI-424 card. I have tried every unit on all four AudioWire ports on the card, as well as swapping all the cables around between them. The issue does not appear to be the card or the cables... the three working units always behave normally (no matter the port or cable) while the one "endless flashing" unit always exhibits the problematic behavior described.
The flashing behavior, since it occurs after the rack unit has been on for a while, seems possibly to be heat related? Once the unit starts flashing, power cycling it does not change anything (already too warm?) -- the indicator starts out flashing and never stops (never goes solid). The only thing that seems to restore normal behavior (briefly) is to leave the unit powered off for many hours (cooled off?), at which point, the sample rate will light solid as normal, albeit only for a short time (until too warm again?).
I have opened up the unit and tried changing the large 15000uf capacitor on the main board, as it seemed possibly domed (though not clearly) as someone else had posted that a similar behavior with their 24 I/O was magically fixed by replacing this capacitor. But, this made no difference in my case.
Anyway, has anybody experienced this behavior with the 24 I/O, and has any advice?
When I first turn the unit on, the sample rate indicators do their normal "scan" before eventually settling on a single rate, which remains solidly lit (for example, "44.1", or whatever was last configured). I can then also configure the unit to switch to any of the four available rates, as normal.
However, after the unit has been on a little while (just minutes) the sample rate indicator will suddenly start flashing by itself and then never stops, no matter what I do. (The unit is set to use the internal clock of the PCI-424, so this is not due to a missing clock signal.)
Once in this "endless flashing" state, the unit is still detected by the computer (PCI Audio Setup can see it, with no error messages) and the unit still responds to sample rate configuration changes (in a way) but the sample rate indicator never stops flashing. Curiously, attempting to set the rate to either 44.1 or 48 always makes the unit switch to flashing only 44.1. Likewise, attempting to set the rate to 88.2 or 96 always makes the unit switch to flashing only 88.2.
Now, I have three other 24 I/O rack units which are working fine with the same PCI-424 card. I have tried every unit on all four AudioWire ports on the card, as well as swapping all the cables around between them. The issue does not appear to be the card or the cables... the three working units always behave normally (no matter the port or cable) while the one "endless flashing" unit always exhibits the problematic behavior described.
The flashing behavior, since it occurs after the rack unit has been on for a while, seems possibly to be heat related? Once the unit starts flashing, power cycling it does not change anything (already too warm?) -- the indicator starts out flashing and never stops (never goes solid). The only thing that seems to restore normal behavior (briefly) is to leave the unit powered off for many hours (cooled off?), at which point, the sample rate will light solid as normal, albeit only for a short time (until too warm again?).
I have opened up the unit and tried changing the large 15000uf capacitor on the main board, as it seemed possibly domed (though not clearly) as someone else had posted that a similar behavior with their 24 I/O was magically fixed by replacing this capacitor. But, this made no difference in my case.
Anyway, has anybody experienced this behavior with the 24 I/O, and has any advice?