[GanjaTron]

Hi everyone,

a heads-up for anyone still using one of these old dinosaur CDROM drives in/with their SGIs. I have two XM-3401s in my Crimson and PowerSeries, ca. '93 and '95 production, and the earlier one no longer reads discs. I noticed acrid smelling electrolyte on the PCB near the connectors, with a TTL and SMD cap nearby. Popping open the cast (!) lid revealed further leaked electrolyte on the PCB with the onset of corrosion!
 
The major culprits are a bunch of 10µF and 100µF 6.3V SMD caps in an unusual thin can package mounted on its side in a rectangular plastic case (see piccies). Desoldering these things released a stench so intense, I had to open a window and leave the basement. I'm now considering replacing these with 5mm diameter TTL caps, also on their side.

You may of course well argue why even bother with such an old drive if a replacement can still be obtained from eBay. But prices for these drives seem to have gone way up since I bought these in the early 2000s for just 10 DM apiece. Now they're listed for 100€ or more. And I expect the replacement may develop the same issues, unless it's a much newer model. But in my experience these old SGIs don't play nice with every CDROM out there. The XM-3401 is a known working config (once you modify the factory block size, ahem).

FWIW, my other XM-3401 from '95 has the same components, but shows no signs of leakage yet, tho ESR was high (>10 ohms) in some caps. I'm sure this one's timebombs will detonate too, sooner or later.

--Roland