Chromatography Forum

Hi, we have in lab a Varian GC 3400, this morning after turning on dislpay says 'HALT ILLEGAL ADDRESS.'
After having cycled several times on the screen appeared the words ' HALT BUS ERROR'.
Neither of the two messages appear in the accompanying manual .. does anyone have any suggestions?

Hi, we have in lab a Varian GC 3400, this morning after turning on dislpay says 'HALT ILLEGAL ADDRESS.'
After having cycled several times on the screen appeared the words ' HALT BUS ERROR'.
Neither of the two messages appear in the accompanying manual .. does anyone have any suggestions?

mai sentito questo errore mi dispiace

Is it hooked to some type of data system? Could this be the source of the error?

The 3400 has an auto test for electronics. With the GC in Ready sate push shift plus test. If anything on electronics fails it will show with a Fault number message.
Perhaps that test give you some more information.

The normal diagnostics are inaccessible in that state as the 3400 should freeze. This error hints towards dirt on the electrical connections or one or more broken board(s), most likely the CPU assembly.
If you have a Z80 board and it's broken I can send you a replacement from my spares.

Please follow these steps after you did electrically disconnect the GC and all accessories:

1.) Remove the upper cover of the 3400 (added fun when a 8100/8200 is installed). Left-hand you now have access to the electronics compartment.

2.) The main reason for this error is a fault at the door assembly. Check the electrical connectors of the door assembly which connects it over a flat ribbon cable to the main board (open and re-seat). Restart the GC so see if this did fix the error.

3.) Now connect the round connector "GND" with the connector "DIAG" (has a bar above the writing) on the CPU board with a crocodile clip. Then start just the GC and see if diagnostics starts. If so, you're getting an error code which should explain this mess. If not, proceed.

4.) You see several yellow levers labelled "CPU" etc. Flip those levers to release the cards. Release all levers except CPU.

5.) Check if GC starts. If so, turn all levers back (while the GC is OFF!) until you see the error again. The last board you did connect is the culprit.

6.) Ground yourself (earth strap to wrist).

7.) Pull each card out, blow softly over the connector, blow softly inside the GC or vacuum it. Then reseat the card softly.

I'm curious about the results.

The 3400 is a dependable workhorse (minus dirt in the electronics compartment, bad fans and oven motors and overheating of electronics).

Check if the rear fan is operating correctly and noise-free. If this fan fails the whole GC will die from overheating due to failed cooling (seen that in other labs).

Any news?

To me, the most important new is that you are a Varian expert. I have now three 3400 plus a 3800 and a 430 Gc's working. Sometimes I have problems with them...
May I have the possibility to have your e-mail to ask for help when necessary?

Thanks for the warm words

I believe in open access and public information. So it's more helpful to discuss those issues in public as more people can learn from it.

Please let me know if there's a justified exception from that

Not, really there isn't any reason to use private e-mail. I only was thinking over the possibility of boring other chromatographers...

I guess it's always worthwhile to increase the available knowledge and I'm sure nobody would be bored by any instrument problem.