it may or may not apply to you, but this is required reading:
http://www.rme-audio.de/en_support_faq.php?page=content/support/en_hdsp_pci
i just "lost" my HDSP card, which was a rev 3. no idea if it caused by the same
problem - it had been working in the same computer for several years.
unfortunately my card is a HDSP 9652 Rev1.6, and the regulators layout is not the same. So
no modification worth trying, it looks like they've already upgraded the capacitors in
this revision.
thanks for the info, interesting anyway !