Molecular Devices SpectraMax ABS Plus - Optical Alignment Procedure (SOLVED)

[fmashockie]

Hey y'all.  I know this is a long-shot.  But I'm pretty desperate at this point so I figured I'd tap the EEVBlog to see if anyone can help.

I am an in-house engineer maintaining the lab equipment for biotech company.  In >90% of the ~400 pieces I am responsible for, the manufacturers will not provide service manuals, schematics, etc.  Very limited resources for the customer to repair the instrument themselves.  This is a topic in itself.  But it is the most challenging part of my job.

I am trying to repair a Molecular Devices SpectraMax ABS Plus. It is a spectrophotometer (called a microplate reader) for measuring absorbance of 96-well/384-well plates for biological/chemical samples.  The unit has developed a 401 error - which according to the manual states 'the filter wheel is unable to find its photo interrupt'.  Usually, when the manufacturer uses the term 'photo interrupt' they are referring to an optical homing sensor.  However, the filter wheel in this unit has no optic homing sensor.  The predecessors to this unit (such as SpectraMax M2) did have homing sensors for their filter wheels.  This is just an example of how bad this company's manuals are - they just kept the old error code descriptions.  In fact, the only note they provide in the maintenance section of this manual (besides the error codes) is how to replace the fuses!!!! 

Anyway, I found out that this error usually means the optics are misaligned.  I can see that aligning the optics is accomplished by making adjustments to set screws on the diffraction grating (or monochromator).  But the problem is, I have no way to control the Xenon flash lamp manually.  It only comes on while running an experiment or during the unit's initial start-up calibration/initialization.  I need to be able to control the lamp to keep the beam on as long as need while I make adjustments to the diffraction grating.

Usually lab equipment like this has two operational modes 1) normal use mode 2) service mode.  The service mode is usually kept hidden.  It is either a different application entirely (buried in the program files folders if you're lucky) or it is enabled by some keystrokes within the regular software app.  I was unable to find any service mode for this unit.  I was however able to open a 'chat window' by pressing CRTL+SHIFT+ALT.  In this window, I can type 'error' for example and get a list of all error codes triggered by the instrument over its lifetime.  I tried typing things like 'lamp on' to see if I could turn the lamp on, but no success.  I was even able to externally control the lamp with my power supply and pulse generator, but this doesn't seem practical either.

I apologize for the lengthy post, but I am hoping someone on here might know a procedure for the optical alignment of these instruments.  As I said, it is definitely a long shot.  It would probably have to be someone who worked for Molecular Devices or has lengthy experience repairing these model microplate readers.  I don't have high hopes, but I figured I would at least try.

Thanks in advance!

-Frank

[vindoline]

Hi Frank, I feel your pain regarding analytical lab equipment! HP has such wonderful old service manuals for it's electronics test gear and ZERO available for it's HPLC's. Like yourself, I maintain and repair a lot of chemistry and life sciences lab equipment - however I don't have any experience with the company or model that you're working on. That said, I would be hesitant to start 'adjusting' the optical alignment without the proper tools and documentation. Usually these adjustments are locked down pretty tight and, unless there has been physical trauma to the instrument, they rarely 'go out.'
I would start by looking at the mechanicals. If this unit does have a filter wheel, can it move freely? Does the stepper motor function? etc. Another area to check are cables and interconnects. Then there is the gospel according to Dave "always check the power rails!"
I know I'm stating the obvious. No insult intended! I wish I could help more and I'd love to see more discussion of chemistry/biotech lab gear on the eevblog.
Good luck!

[fmashockie]

Hi Vindoline,

Thank you so much for your reply.  I started out as an analytical chemist and got my degree in chemistry.  I worked for years with HPLC and GC.  I eventually got a job repairing HPLC/GC at GSK.  And then changed to my current role working for a biotech company.  No HPLC/GC here.  But my favorite HPLCs were Agilent/HP.  While yes they also had poor manuals related to servicing, like their electronic test equipment, they do keep serviceability and ease of use a top priority.  They will at least sell you spare parts and provide some details about servicing.  For the 1100/1200 series, I used to use a module (we called it the gameboy) that would give you a bit more manual control of the instrument.  It could do testing on the pump and mixing valve to verify they were in working order, as well as lamp intensity tests.  So I do give them credit there.  However, not sure if their latest offerings are still as easy to service.

It is a real shame that these companies all employ these repair preventation strategies.  All of them do so in some form or fashion.  But this company Molecular Devices is one of the worst offenders that I've seen.  They refuse to sell spare parts, and provide no help whatsoever when it comes to servicing.  Also, they charge an arm and leg upfront for any repairs.  A quote from an email exchange with one of their tech support reps 'Molecular Devices does not support customer servicing of instruments'.  How did it get this way???

But anyway, unfortunately I have confirmed with certainty that this is an optic alignment issue.  The filter wheel moves freely and its stepper motor operates.  The diffraction grating motor also works and homes itself as it should.  I am not ready to give up yet, but I know if I had a procedure and/or additional service tools (for example I fear that Molecular Devices might use an additional service app not available within the software provided to the customer) I could get this fixed easily.  It things like this that make my job the most challenging.  I still love it though!

Glad to hear from another fellow lab engineer.  I don't run across too many people in roles like mine.  I wish there was a forum like this for people in our line of work to share tips and tricks - especially with the way these companies employ these repair preventation practices.

Thanks again for your input.  I truly appreciate it!

-Frank

[fmashockie]

Update: I was able to teach myself how to optically align the instrument successfully.  I made a video that I posted on my YT channel on how to do this.  It is too long (like most of my videos  ) because I go into additional details on how the instrument works and I do a lot of ranting, but I tried to thoroughly timestamp the video so people can sift through what they need to perform this alignment.  It is possible with patience and the right tools!  AND you can save yourself a ton of money doing this yourself.  Because if you/your company owns this instrument, and this happens to you, Molecular Devices will likely charge you upwards of $5k to fix it.  Good luck!