Chromatography Forum

I started browsing the forum and it surprised me when I found so much users for Varian 3400. I´m having problem with one of these (power suply overheating) and need the schematics to check some conections. Anyone knows where can I find these schematics? Or service manual?

Thanks,

Redi Siqueira

Please describe the exact nature of your problem

The cable that goes from power suply to J31 on the mainboard has overheated. I replaced the wire and took the voltage reading (20v) but I don´t know if this is the right. The GC started ok (but the error messages I mencioned at the other post).
Till now, it is working well, but I would like to have a better understanding of the equipment.

Thank you for your interest.

Regards,

Redi

There is no J31 in any schematics I have.

Please re-check and take a picture so I can see the actual position.

It might be J21 which carries the net voltage.

I sending you a photo of mainboard and signed J31 conector and also a little burned path.
First time I try to put an image here, if you can not see it, please, let me know.



Thanxs,

I don't see an image, please give the URL.

Link for GC 3400 Mainboard photos:

https://picasaweb.google.com/1003974325 ... directlink

Well... the part number hints towards a mainboard for a Varian 3600.

The burned path carries one of the terminals of the ignitor voltage for the FID (J 18).

None of my diagrams show a J31 but the visible connected line between J 18 and J 31 on the circuit board carries one terminal of the voltage for TSD no. 2.

HbJ:
Do you know which would be the rigth voltage for the ignitors? Both of them (2 FIDs in the system) are open and I´m thinking if its not related with this conector.

Open in what way?

If you can't ignite them, it's said connector. According to the specs, it's delivering 3.8 V to the ignitor coils.

The coils are open. The analyst is doing the ignition manually, with an eletric lighter till new ones arrive, but I´m afraid the new ones can burn again if the circuit is not ok. I even thinking in recommend they do not change the ignitor probe and live with the problem till buy a nem GC.

At J31 conector (wires from power suply to conector) I read 20 v !!

That is okay as J31 is the TSD voltage which is around 18 volts.

J18 carries the ignitor voltage.

Just a hint: The ignitor voltage must only be present when ignition is demanded. If it's stuck on you have an electrical problem (just saying).

OK, HbJ,
The system is running without the ignition (I´m using an external ignitor) and seems is ok. I´m still afraid to replace the ignitor for a new one and burn it again.

Thanxs a lot.

OK, HbJ,
The system is running without the ignition (I´m using an external ignitor) and seems is ok. I´m still afraid to replace the ignitor for a new one and burn it again.

Thanxs a lot.

That's fair Have fun with your 3400!