HPLC Troubles

[Sallybeetle]

My lab recently purchased a "refurbished" Waters 2695 Alliance / 996 PDA detector system. Does anyone have advice on this type of system?

I have had nothing but trouble. No insult to Waters intended. I have heard that these systems can be real work-horses in the lab.

Even after replacing 3 boards, the detector has some sort of consistent spiking that occurs 30-31 minutes apart, with or without pump, with different lamps, on different HPLC systems, with or without UPS.

The 2695 fails the Static Leak Check, Valve Check (V1-V2-Above Seal-Below Seal), and Compression Check in the diagnostics mode. The Adjust Seals test passes. It also self-powers down if I run the attached column heater and/or sample compartment heater/chiller. I got good %RSD, Tf, and Rf on a 15 hour testrun using a 996 Detector that was already in the lab.

Any advice would be greatly appreciated.

[tom jupille]

I'm not trying to rub salt into any wounds, but your post said "refurbished" as opposed to "used". Generally, "refurbished" equipment should meet the same performance standards as new equipment, and should carry some sort of warranty. I certainly wouldn't pay for it until it had passed it's incoming qualification tests.

[Ron]

It can be a very bad experience if you buy refurbished equipment from someone other than the manufacturer or an established third party organization. With the amount of work that has been done on the detector already, I would suggest that you get in contact with the company you bought the equipment from and ask for a refund, or for the instrument to be put in working condition in a short period of time. Refurbished equipment can be very reliable and save a significant amount of money, or it can be buying someone else's headache.

[Consumer Products Guy]

My lab purchased a refurbished HPLC system (HP 1050) from Alpha Omega a few years ago, and it still works fine. It had a one-year warranty, had one issue during that time, and Alpha Omega replaced the VWD optical bench under warranty. We were very satisfied.

[DR]

I would send the system back unless the vendor is willing to send someone w/ a trunk of parts & a tent so that he/she doesn't leave 'till it's fixed.

The spiking sounds like maybe the power supply has gone south...

[kweston]

I cut my HPLC teeth on Waters equipment in the late 80's. I use to swear by Waters equipment, now I swear at it. We have several Alliance systems (ages from 1-3 years) and some work fine, others spend more time with Out of Service stickers than in service.

Is your system connected to a network? Are multiple systems connected on the same line to the server? I experienced a signal (very reproducable square wave) feedback through a SATiN Box. I discovered (not the Waters Srv Eng) that it was coming from the Pelttier cooler from a second system. They replaced the cooler and the problem went away.

The example may not relate to your problem, but sometimes problems are not what they appear to be. Do the simple things first, review instrument methods for events (Alliance and detector). The suggestion of power supply is valid and I recently (last week) had a conversation with Waters about this same issue.

Good luck.
KW

[BenNC]

How good is the temperature control in your lab, and how close to a vent is your detector? I had a similar problem that went away when I turned off the HVAC in my lab. I was seeing about a 2 degree swing in temperature, but more importantly the vent was blowing cold air directly on the detector. I'm still working on a solution. Fortunately I don't have to run the A/C much this time of year

[Sallybeetle]

Thanks for all of your replies.

The system is on a surge protector plugged directly into the wall outlet. Two other HPLCs are plugged into an UPS which is plugged into the same wall outlet. However, I observe the detector phenomenon even when the other LCs are down and when the detector is hooked up to the other computer system and UPS. This time of year, the heat is on. But, the problem has been observed at all times throughout the day.

DR: I like your solution of the trunk full of spare parts and a tent for the repair person.