[marcotf10]

Hi everyone, I didn't know who to ask so I thought about posting here. I just finished preparing a new batch of standard and as I was about to validate them, the plasma wouldn't start. We have a Varian 735 ICP-OES and its in a terrible shape.

Previous user let the machine sits in strong acids and as I removed most of the covers, I was able to observe how bad it was. And it was BAD. But I showed some love to it, removed all the rust, cleaned all the dust, changed some parts, changed the coil and it kept working for a while, until the PSU and the power tube gave up and brought the power board with it. I had that fixed by our electrical engineer (I work for a multinational lab consortium), adjusted the voltages back to -4.44 and it worked for a month and a half.
Then today, it failed to ignite and it gave the dreaded error : RF Failure

Here's what I did so far:

1- Checked the power in the instrument status as the sequence progressed. Power wouldn't kick in in the ignite phase.

2- Checked the fuse TP1-TP2, working as normal.

3 - Argon is flowing as normal, nothing suspect here.

4 - Tried rebooting the PC and the ICP. Then I unplugged the ICP from the wall socket 20 seconds.

5 - Monitored the voltages with a multimeter during ignite phase, current would rise for a second or so then fail, but would never reached even half of the spec.

6 - Tried to trip the breaker on and off. Doing so produced a noticeable electrical short sound.

7 - Tried a longer ignite phase in case there had been a RF timeout. NO luck there either.

8 - During the ignite phase, I can hear a loud buzzing sound as if the generator was working as hard as it could but would produce no power.

I have access to service mode but I'm not sure what to look for to check whether the problems sits in the power tube or the PSU. And I'm not sure why they broke down so fast, they are brand new spare parts from Agilent. Might be a lemon, but still.

[Corribus]

Sounds like it's time for a service call. I run and maintain essentially the same instrument (720 ES). We recently had an RF failure accompanied by a torch malfunction. Turned out it was a problem with an internal component - power supply inside was shorted and some board was damaged. Took the technician the better part of a day to repair, far beyond my ability. Never figured out what caused it but suspected it was the crappy power in our building. We've had a computer blow and it's on the same circuit.

Anyway, I know it's expensive but you might save yourself time and money in the long run just to have Agilent come out and service the thing.  At the least, call them on the phone.  Our local technician in the past has tried to troubleshoot things over the phone and not charged us a dime.

[curiouscat]

I have access to service mode but I'm not sure what to look for to check whether the problems sits in the power tube or the PSU. And I'm not sure why they broke down so fast, they are brand new spare parts from Agilent. Might be a lemon, but still.

I can't help much but I wanted to commend you on at least trying to debug yourself.

So many people treat instruments like a black box these days: I've seen chemists that know nothing beyond injecting and pressing a few preset buttons on the LCD panels.

[ICP-OES]

Hi Marcotf10.
Have you solved your RF tube problem? I have same problem with our ICP-OES and our ICP model is same as yours.
Agilent ICP technician visited in our lab a month ago but problem is not solved. Could you advise me in this issue please?