DP9 breaking contact with 2408mk3 & 24i/o

[lampfilmusic]

Using DP9 with MOTU 2408mk3 and MOTU 24i/o. Usually everything works fine, but lately with one project, DP9 keeps losing its connection with the converters. I've checked the cabling and the settings for MOTU PCI Audio Setup, all looks correct.

Does anyone have any tips for how to fix this issue?

Thank you.

[mikehalloran]

The first step is to do some normal maintenance on your old Mac:

Shut down. Remove the power cord.

Replace your NV RAM battery. If original, it will be a high-heat BR2032 which you can get at Amazon but if you've replaced the HDDs with SSDs, a common CR2032 medical battery from the drug or grocery store will be fine—electrically, they're identical but the BR is heat shielded.

Burnish all peripheral connections at both ends by unplugging and re-plugging at least 3 times.

Burnish the 424e card by removing and replacing 3 times (if I had to guess, this is the second most likely cause).

Check the heat sink fins over the CPU and clear them if clogged (this is the usual culprit).

Put everything back together.

Do a Safe Boot by holding the Shift Key — log in, wait for any desktop icons to rebuild. Shut down and reboot your Mac.

Start DP 9 in Safe mode by holding down the Shift key. Quit DP and start normally.

Now see if you still have a problem. You might but if you do, you'll have narrowed down the potential causes to your 424 card or one of its interfaces. Far better than chasing the symptom first and then finding out the actual cause was a maintenance item.