Chromatography Forum

We have a 5890 we use in our GC-MS setup. It stopped responding so we powered it down and then it would not power up anymore. When you turn the power switch you can see a faint flash in the run and not ready led's. We have a parts 5890 and were going to try to swap the power supply board to see if we could get it running again. This issue is the original board says Rev C and has a pig tail on the one corner with three wires going to a metal cylinder with a bolt coming out the end that you bolt to the frame. The card we have that we wanted to try in it does not have those three wires on that section of the PCB. There is just a resister in that area. Here is a picture from the net (not from our machine) of the power supply board with the pig tail. I think it is a triac maybe?



Would it be possible to use the board without the pigtail (maybe a triac?)?

I was discussing this with someone else and wondering is it possible for the AC board to be working and the the DC transformer to go out. Nothing powers on when you plug it in. Just a flicker in the ready/not ready led's. The oven fan does not come on. We checked the fuses on the mainboard and AC board.

Check the AC voltages coming out of the transformer , you must measure some voltages on some pins , if the transformer is not completely out of function.

If you have no voltage , then check the power switch.

If you have voltages , connect the AC board , and check the voltages on the main CPU board.

The AC board has robust components ; capacitors , relays etc ; very difficult to destroy.

We have a spare parts GC and noticed on the back of the GC on the power supply tray it lists 200/220/240v and there is a yellow sticker around the 240v. However this is a 120v machine. The current machine we have just has the 120v designation on the back of the power supply tray.

Also the current GC we are working on has an AC power supply board with rev C on it and a pigtail which I think is a triac. The one we have for parts is a rev A with no pigtail. Would these two boards be compatible?

If the revisions are that far apart, you want to look at the other boards and see what revisions they are. There were many changes throughout the life of the 5890 so what will power one revision of main board may not power another.

Check the AC voltages coming out of the transformer , you must measure some voltages on some pins , if the transformer is not completely out of function.

If you have no voltage , then check the power switch.

If you have voltages , connect the AC board , and check the voltages on the main CPU board.

The AC board has robust components ; capacitors , relays etc ; very difficult to destroy.

Just wondering if you could give some guidance on which pins to test to the voltage on the transformer?

I don't know the pin connections of the transformer , but anyway you can test it.
There must be a socket directly coming out of the transformer.
Adjust your voltmeter to measure AC volts.
Connect one of the voltmeter probe to any of the socket pins , touch the other pins one by one ,with the other probe.
If you can not read a voltage , try another pin and so on.

If the transformer is working , you must read AC voltages , at least on some pins.
If no voltage , then proceed to check the mains switch and mains fuse.
Also check the power cable.

Good luck !

Here is a link to a copy of the service manual: http://ipes.us/used/58901.pdf

It should (last I checked) include points on the main board where you can check voltages.

We tested the voltages and they all looked good. We also test the voltages on our extra power supply and they looked good. We tried plugging the extra power supply in and it does the same thing so we are thinking its the motherboard. Our current GC has Rev F motherboard. Our extra GC is Rev B. Are they compatible?

If you have EPC on Rev F it may not be supported on Rev B. Those are several years apart. Are the two instrument the same 5890 or 5890A or 5890 Series II? Each change in instrument used different mother boards and supported different options that were newly introduced. Look at the control panel on each and see if they have the same labels on each button on the keypad. That will tell you how compatible they are with each other.

There are a couple of in-line fuses on the 5890 motherboard that will give you exactly the symptoms that you are describing. if you have the 5890 service manual it will show you the exact location of the fuses. You should check them and make sure that you didn't blow them.

There are a couple of in-line fuses on the 5890 motherboard that will give you exactly the symptoms that you are describing. if you have the 5890 service manual it will show you the exact location of the fuses. You should check them and make sure that you didn't blow them.

Thanks for the info. We did check all the inline fuses for continuity as one of the first steps.

We ended up getting a used main board and that fixed the GC. Thanks for all the help.