Late in the afternoon of Thursday April 12th we experienced catastrophic instrument failure on Yosemite, the walk-up 400 MHz NMR in SBC. Without going into too much detail, the problem was that the instrument was not producing the proper frequency radio frequency (RF). As you can imagine incorrect frequencies lead to a myriad of problems with NMR spectroscopy.
Unfortunately, I could not get parts to repair before my trip to ENC (my flight left Saturday morning) so I tried to patch together a work-around, which did not seem to work for anyone. Hence we had no walk-up NMR in SBC the week of 4/15/12. Yikes! My top two priorities upon returning were #1) get a work-around and #2) fix Yosemite. With the gracious help of Frank and Conrad of the SCC and CMLD, respectively, I was able to provide access to displaced Yosemite users on BigSur. To fix Yosemite, I spent a lot of time with the oscilloscope troubleshooting (aka scratching my head saying - "is that the way that output is supposed to look?"). Once I thought I'd isolated the problem I contacted Bruker center but they told me (in essence) "you have to replace your 10 year old fans before we'll send you any board so that you don't burn up our boards!" Then they gave me a quote for the fans ($30/fan) and mounting screws ($1/each) with 2-4 delivery time! Realistically, they probably could have delivered faster, but the price along with the delivery time and a delay in response prompted me to find the fans from a third party. The fans (NMB 4710KL-04W-B50-E00) were easy to find (I got them from newark.com). The mounting screws were tougher. Thanks to the resourceful Geoff Akien from CEBC I found them on Xoxide.com.
An ordering and delivery delay set me back a couple of days, but when I received and installed the fans, I was stunned to see my signal generation unit behaving. I borrowed thermocouples from HotRod Todd Williams in the MS lab and compared the temperature of Yosemite and BigSur. Holy cow, these console produce a lot of heat. It seems that microbay consoles are engineered on the edge (with regards to heat dissipation) and any diminishing cooling power can lead to terrible consequences. Moreover - and I put this as a warning to fellow managers - the fans Bruker will try to sell you are not perfect replacement in terms of air flow. Get the exact same fans or (if your fans are no longer sold) call NMB and make sure you get equivalent fans.
I have the hunch this story is not finished yet, but I've opened Yosemite back up to all trained users. I'll have to keep a close eye on this. Also, I replaced the fans in BigSur in 2009 with fans I bought from Bruker. I'm concerned they have a lesser airflow, which explains my strange problems with the GCU earlier in the spring and last fall.
Keep on precessing.
Justin
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