Chromatography Forum

Hi

I have an Agilent 1050 with a 79855A autosampler (21 vials tray). The tray is not rotating correctly. Sometimes it works sporadically.

Problems:
-the unit is making weird noises when it rotates
-it stops rotating before reaching the desired sample vial and stays stuck in position
-sometimes it's unable to return to the home position and rotates slower than usual

Any help would be greatly appreciated!

Here is the run log of a failed run:
443 41e0 55df6bb2 202
Method Method started: line# 5 vial# 5 inj# 1 12:57:38 08/27/15
67 41e0 55df6bb3 0
Method Instrument running sample Vial 5 12:57:39 08/27/15
d48 41ce 55df6bd8 400
ALS 1050 1 EA 4006 12:58:16 08/27/15
0 1da8 55df6bd8 0
Instrument PMP1 did not start a run 12:58:16 08/27/15
0 1da8 55df6bd8 0
Instrument LDAD1 did not start a run 12:58:16 08/27/15
0 1da8 55df6bd8 0
Instrument LFLD1 did not start a run 12:58:16 08/27/15
67 41e0 55df6bd8 0
Method Instrument Error - Method/Sequence stopped 12:58:16 08/27/15
67 41e0 55df6bd8 0
Method Method aborted 12:58:16 08/27/15

It probably needs to be serviced. Good luck with that...

Welcome to the forum.

That is a pretty old piece of hardware, and it probably needs at least a good clean up. I doubt very much that there is official service support, so if you do not want to do it yourself you will need to find a lab service technician who is able to take a look at it. The good thing is that the mechanics in the older generations of equipment are more robust than in the new stuff.

Good luck.

Peter

I have some parts scavenged from a working 1050 autosampler available, if you're in USA. And we just literally threw an entire working 1050 autosampler module (and other 1050 modules) into the to-be-recycled bin in our warehouse.

Could be a worn or defective IR position sensor for motor (IR sensors are rated for 10 years. Their output decreases over time). We see lots of worn out IR sensors on the older 1050 and 1090 units. These sensors can be replaced. A worn gear or belt drive is possible too. When the carousel "sticks" it is usually because someone has physically damaged the unit (not installing the tray correctly and breaking off the key-tab. I would confirm that the tray is in perfect condition and mates to the drive unit below before running any other checks.

I would also clean the entire unit and check for wear in the usual spots. Used parts and whole 1050 A/S assemblies are available on the web and can be used as source of spare parts. These are very rugged units (already over 20 years old) and if maintained, should be able to last 40-50 years!