5973 High Coil Voltage/Difficulty in Mass Filter Electronics

Discussions about GC-MS, LC-MS, LC-FTIR, and other "coupled" analytical techniques.

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I've been working for a few months now on getting a long-neglected 5973 up and running.

I hit a snag in that, initially, tuning would error out with "difficulty in mass filter electronics". I spent a while playing with dipping the coils, and at m/z 20 the lowest I could get them was ~1700mV. The software maxes out at 2000mV, and I couldn't get a voltage reading at much over 20 m/z(forget the standard 100 m/z then 500 m/z dips).

After some consultation with a few folks, we diagnosed a bad sideboard, and I was able to buy a working used one.

I finally got around to installing it today to find...the same thing. I'm getting roughly the same RFPA voltages as I did on the old sideboard, which I'm guessing means that there's a problem somewhere outside it. I find it hard to believe that two sideboards would fail basically identically.

As I understand it, RFPA only deals with the quads/RF coils, so any issues with too high of a voltage there is a problem somewhere in that.

I'm at a bit of a loss as to where to look, though. I did-carefully-remove, clean, and reseat each of the wires going to the coils. I've verified that they're not touching each other or the quads.

Looking down the quads with the source removed, the gold foil looks nearly perfect, so at least they pass a visual test.

This is a diff pump instrument and there was some oil splatter from backstreaming, but I think that's all cleaned up.

I'm debating about Agilents "never do this" clean quads by-hopefully-running DCM down them(just removing the analyzer door, but not removing the quads from it).

Can anyone suggest other places to look? Maybe something obvious I'm overlooking?

Also, is there somewhere else that ties into all of this? I'm if I should be paying attention to the BNC connector to the EM, which is kind of nasty looking, or to the white HV cable that looks sort of like a miniature spark plug wire.
The spark plug wire is the high voltage to the HED. I have had that go bad before. On a 5975 I had the tip of the connector break off in the wire or in the pass through(can't remember which one has the pin) and it caused all kinds of problems. It was probably the pin in the pass through which is easy to replace, it just has a plastic nut on it and an O-ring seal.

IF you clean the quads, remove the source, the board with the wires that connect to the source and the EM, I think those are the only plastic coated wires inside the analyzer. I can't remember if DCM is the recommended solvent or not. The last analyzer I cleaned was on an ICP-MS and the whole analyzer minus any boards was submerged in solvent, but of course that one took forever to dry since it has a lot more ceramic in it. Once you do clean I would reinstall it and let it pump at least over night to remove as much of the solvent from the ceramic end pieces as possible. If the diffusion pump did actually backstream then there will be some of that fluid on the quads, but there is usually a little just on the baffles above the pump even if it didn't.
The past is there to guide us into the future, not to dwell in.
Make sure all the electrical connections to the quad are good and tight. Had a thermo quad a while back that had essentially no RF on it. Simply tightening the nuts on the RF connectors fixed it.
Might be something as simple as dust/hair shorting on the rods. If you are really lucky a blast of compressed air might fix it.
In my experience dirty quads just have bad peak shapes, unless they are really dirty/dripping in diff oil. RF problems are normally an electronic/connection issue.
Wanted to FINALLY follow up on this one.

I got brave and pulled the it down to the quads. Once there, I cleaned the "springy" contacts themselves and also the place that they touch on the quads, then bent them a tiny bit to give better contact.

Once I pumped it all back down, everything worked beautifully. The coils dipped to a little under 700mV at 800m/z and the instrument tuned to 1600V on the EM.

As I type this, I'm waiting on my first test sample to come through it, and hopefully see some life fron an instrument that hasn't operated in 10+ years.
benhutcherson wrote:
Wanted to FINALLY follow up on this one.

I got brave and pulled the it down to the quads. Once there, I cleaned the "springy" contacts themselves and also the place that they touch on the quads, then bent them a tiny bit to give better contact.

Once I pumped it all back down, everything worked beautifully. The coils dipped to a little under 700mV at 800m/z and the instrument tuned to 1600V on the EM.

As I type this, I'm waiting on my first test sample to come through it, and hopefully see some life fron an instrument that hasn't operated in 10+ years.


Congrats!

I have not had the quads out of a 5973 and up yet so wasn't sure how those connected. I know the same part used to be a weak link in the 5971/72 models and replaced those many times.
The past is there to guide us into the future, not to dwell in.
James_Ball wrote:
benhutcherson wrote:
Wanted to FINALLY follow up on this one.

I got brave and pulled the it down to the quads. Once there, I cleaned the "springy" contacts themselves and also the place that they touch on the quads, then bent them a tiny bit to give better contact.

Once I pumped it all back down, everything worked beautifully. The coils dipped to a little under 700mV at 800m/z and the instrument tuned to 1600V on the EM.

As I type this, I'm waiting on my first test sample to come through it, and hopefully see some life fron an instrument that hasn't operated in 10+ years.


Congrats!

I have not had the quads out of a 5973 and up yet so wasn't sure how those connected. I know the same part used to be a weak link in the 5971/72 models and replaced those many times.


Thanks!

Honestly too the school where I am now doesn't know what to make of the fact that I just kind of walked in and did this.

They got a $10K quote a few years ago for Agilent to come out and set up "assuming we just have to hook it up". Considering that they didn't have a computer and what I've done has gone beyond just "hooking it up" I think they'd have spent a lot more than that with Agilent.

Also, they have a 5890+ TCD/FID that they've had for YEARS. The computer died a while back and they junked it, and they had removed the autosampler because apparently "it kept bending syringes." They had been using a stopwatch and the signal display for the FID on the front panel to collect RTs on compounds, but of course that doesn't give area. This one has an EPC packed column inlet-actually I think it has two of them-but the only one active is on the FID. Among other things, the ignitor hadn't worked in a long time, so I did an FID service and both improved sensitivity and got the ignitor working again(it was a bad ground-the nichrome wire was fine). The TCD isn't connected, but I need to explore it and see if it's dead or not.

In any case, I set up the autosampler again(it's fine) and I'm running the 5890 system off MSD Chemstation(I think James that you were the one who clued me in on doing that, and I like it better than the standard version of Chemstation). Once I can get a G1512A box, I'm likely transplanting the tray and tower to the 6890, although those are inexpensive enough these days that I'd be tempted to leave the 5890 autosampler intact.

I'm pretty sure I could install G1701DA-I have the install media, and have been told by someone who would know that my BA key will likely work. The only issue is that I'm not sure what 5890 support looks like on DA. Agilent's compatibility matrix says no, but I seem to vaguely recall that there's a simple-ish patch to get DA talking to a 5890(I know 5971/5972 support is a lot more complicated, although CA supports the 5972 on a 6890).

Longer term, though, or actually maybe with leftover budget money this year, I'm hoping to have Geoff with Great Lakes Technical(who's helped me get this working all along) come out and do the "low budget" JetDirect/SCIII LAN conversion and supply an E.02.02 install in Win10. He's told me about $6K(waiting on a formal quote) for the parts, labor, and software to do it.

On another note too, I've been trying to scrounge up an HPLC. I learned on an HP 1050, so that's my go-to choice. I asked Geoff about it in a conversation yesterday and he said that he'd really advise against putting time and money into a 1050 and instead going to an 1100. I spoke with another independent engineer out of Cinncinnatti who I respect a lot and who actually is the reason I like 1050s so much(convoluted story there) and he was a bit more...colorful...in telling me that it was a bad idea and instead to get an 1100. It sounds like that's where I'll be headed-I just need to find a budget system!(although I've been trying to negotiate some 5971 service for a 1050 from a school I'm very well tied into back in Kentucky-they just don't want to let go of their long-idle 1050 quite yet).
I would vote for the 1100 also. I think for software it would be much easier to find something compatible and I believe you can bring the firmware up to about the newest version so it is compatible with most any generation of software.

You might even look into the 1200, which are pretty much the same hardware with better electronics. Those are old enough now that the price is about the same as the 1100.

I think Geoff is the one who did our 5973 upgrade from HPIB to LAN a few years ago. I have since upgraded it from W7 to W10. W10 can be a little picky with the connection if you have two LAN cards in the PC. I have to disable the one to the house network, open MSDChemstation, then reconnect the house LAN, or it gives me the "Already in Use by another Chemstation" error. Easy way is to pin the Network window to the task bar then it is just two clicks to disable/enable the card when starting up the instrument.
The past is there to guide us into the future, not to dwell in.
I have a computer around somewhere with an LC A.03.08 license on it, so that part actually funny enough isn't a huge deal to me.

Still, though, I'm pretty well sold on the 1100 since the support and so forth is there for it. Someone else I was talking to called the 1100 the "5890 of LCs", which is high praise.

I might have a lead on an 1100 DAD system, which would be great for me. I'll see what happens.
That would be a good description, I have 4 1100 stacks that have been running for 20+ years. If you keep them well maintained they last a good long time.
The past is there to guide us into the future, not to dwell in.
A year and a half ago or so, our Agilent sales rep priced out a pair of refurbished 1100/DADs for us and the price was quite good I thought considering it included set-up/training/warranty. IIRC, it was $15K each for VWDs and more like $18K each for DADs.

At the time, I wanted to replace our two absolutely terrible, horrible, much detested by me Perkin Elmer HPLCs(200? They were semi-new, but before PE HPLCs were rebranded Waters systems). I ultimately wasn't able to "sell" it because "You already have two perfectly good HPLCs".

Granted now I'd settle for anything-even those PEs I hated.
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