Waters 486 tunable UV detector woes.

[artie mckim]

Hello, everyone. I'm having problems with a Waters 486 tunable UV detector. Although fine yesterday, this morning it booted up to a 'Fail 402' error code.

So: I followed manual's advice and checked the lamp, and the flow cell. I believe they are fine. The final step was in the manual was to call Waters.

I did. They have given me directions to check the low voltage lamp power supply. I need to call them back, but there may be a problem with this.

My questions:

1. Is there a good place to buy parts for this detector, other than expendables (like the lamp, the flow cell, etc.)?

2. I need a detector! This is actually the second used detector I've bought, and I don't relish the thought of buying a third one, only to have it conk out on my in 6 months. Can anyonerecommend a good source to buy a used Water 486 unit, with any kind of warrantee/guarantee?

Cheers!
Artie.

[artie mckim]

Well: I spoke with technical service at Waters today, and we ran some simple tests with a volt meter to isolate the problem. It seems that the high voltage power supply is on the fritz.

Waters sells this part, and I've got one on the way. A relative bargain, at $750...if it solves the problem.

Out of curiousity, I tested another dead 486 unit we have in our lab, in an identical fashion. It also seems to have this problem!

I asked Waters Technical Service ifthis is a problem systemic to this particular instrument. It doesn't sound like it is; They thought that a power surge might have caused the failure. I was embarrased when I realized that our instrument was not protected with a surge protector! There is a fuse from the power supply, that had not burned out...

Anyway, the part will be here Wednesday. One of our chemists will install it while I'm away at the ACS meeting in San Diego. Keep your fingers crossed!

BTW: If anyone who participates in this forum plans to attend the meeting, perhaps we could meet. It would do me good to have more friends that are analytical chemists. I would particularly like to discuss the topic of preparative LC with someone.

Cheers!
Artie.

[tom jupille]

This may be small comfort, but I seem to remember one version of Murphy's law which goes something like "an instrument will always protect the fuse by blowing out first".

[artie mckim]

What happened:

I bought the high voltage power supply board suggested by waters, and installed it. Although it passed the test for this component after installation, the unit still wouldn't pass calibration.

I called Waters back, and they suggested a replacement lamp. The next day, new lamp, and the unit still wouldn't pass its calibration sequence.

The tech service guy said that we were at the end of what we could do over the phone. I'm going to have to send it in for repair at Waters.

Turn around for the repair is two weeks, a reasonable period.

Cheers!
Artie.

[JM]

This is a common problem with 486, most of the time it due to bad lamp or fogging of the optics. There is a glass lens after the slit , take it out with care and clean it in absolute alcohol ( be careful not to touch the lens with finger ). you may clean the lamp with IPA using soft tissue paper. This works for me most of the time.

JM

[artie mckim]

Thanks for the advice, JM. Unfortunately, it seems that my problem isn't the lamp, or related to the servicable parts of the optics system.

Waters tech service helped me identify a failed high voltage power supply board, and walked me through the replacement process. After repalcement, the high voltage power supply board passed the test for proper performance, but the unit still wouldn't calibrate properly.

We tried a new lamp, with no success. There were no problems with the flow cell, or the lens you mentioned.

My guess is that the photodiode is damaged, and that what ever occurred in the instrument that damaged the high voltage power supply board also hurt the photodiode. I'm sending the instrument to Waters today, for repair.

My dilemma with this unit is: If I can purchase a used unit for $2000-3000, at what point does it make more sense to give up on my old (trouble-prone) 486 for a different unit.

So far, the devil I know seems better than the devil I don't.

Artie.

[artie mckim]

As it turned out, JM was right. I recieved word back from Waters on my 486 unit, and the optics have been 'solarized'.

They recommend replacement of the grating, the optics window cover, and the lens. It will come to about $2500, about what it would cost me to buy a replacement used unit, with a limited warrantee.

It seems odd, though. I don't understand what could have happened to cause this to fail catastrophically, along with the High Voltage Power Supply (HVPS) board(which I replaced after testing using Waters repair guidelines). The instrument was fine one day, and then both the HVPS board filaed, and the optics became solarized.

The first seems like the result of a power fluctuation, while the second seems more like a chronic condition. It can't be coincidental that both failed simultaneously..

Cheers!
Artie.

[JM]

well !! i think they will replace everything except cabinet

Can you do one thing?? just remove the slit between the lamp housing and optics and put on your detector .and see if it pass through calibration cycle ,if not u need a C-clip opener to remove lense and clean as indicated earlier.

If this works just let us know and hey I cant suggest what u should do with that waters service engineer!!!

JM

[artie mckim]

I'd like to try what you've suggested, but my instrument is being repaired at Waters right now. I do have an identical 486 in our lab, that seems to be behaving the same way. It was left for dead when it could not be fixed using the troubleshooting strategy in the detector literature, and Waters tech service was unable to provide further guidance. I kept it as an organ donor for the replacement unit we purchased used.

I should try as you suggest on this original unit, as I have nothing to lose. I believe we cleaned the lens between the lamp, the flow cell, replaced the lamp (and aligned it), and swapped out the photodiode from our working unit to see if it would work. We tried the same test of the HVPS board given to us by the Waters technical service people, and it seems that the board is dead on this unit also.

I don't know why, but it seems that what ever happened to out current unit (under repair) might have killed the original our lab abandoned.


For the record: I've had a good experience overall with Waters Technical Service. They helped me test the unit beyond the simple things in their literature, at no cost. I realize the unit I am working with is an old one, and am glad I still get parts and service for it, although a little pricy. And: When I got to the end of the road and could not repair the unit myself, it sounds like it won't take long for them to get my unit repaired and sent back, so that we can get back to work.

Cheers!
Artie.