[uisdean]

I'm not sure about the fader, but the rest sounds likr the PSU, I'm assuming that you havn't replaced the PSU yet, here's a previous post of mine for repairing the PSU, when ours blew we lost the monitoring and the faders, sounds like yours isn't so far gone, Good luck.....

Like many others I've had problems with the C24 causing me to lose faders and monitoring, I had the added hassle of the product never having been registered despite being purchased from a major UK reseller, registration took 5-6 weeks to complete due to a mix up with serial numbers (the origional desk had been recalled from the reseller before we took delivery of it) as the C24 was not registered I had to speak with digi through their premium rate line which is a bit much when you have purchased £30000 worth of their products! The PSU finally arrived after 2 months but minus the caps and instructions for the fader board mods this took another 2-3 weeks. Thankfully, despite recieving no information from digi I repaired the old PSU which kept our dubbing suite running during the registration fiasco. I'm passing on the details of the repair for the electronically minded amongst you, the PSU is a fairly standard design and the components are all off the shelf.
First check that the fuses ZF8 and 9 are blown,
Replace the following components: IC1, IC2, IC4, IC5 (voltage regulators)D7, D8, D9, D10, BR2 and the 2 associated smoothing caps.
This should restore the +/- voltage rails for the monitor and fader sections.
Make sure that you replace the fuses with the same anti surge 3.15A type as 3 amp fuses will burn out within a day. (This is probably the cause of the failure, the PSU is being run hard)
This repair allowed us to continue operating although there was a hum present on the mic pres so an external mic pre was required.
The repair is only intended as a stop gap as the PSU is continuing to run hot and many of the components are showing signs of thermal damage. Has anyone else repaired the PSU?