EBME Forums Forums Maintenance Technical Assistance TUTTNAUER 3870E NOT WORKING CORRECTLY

Hello, maybe somebody can help me with a problem with a Tuttnauer E3870E atuoclave: It works fine but when it reaches the dryong cycles, the unit just stays there forever, never ends the cycle, the same will happen if I only choose the drying, stays there forever, and in both cases, the keyboard just stops working, nothinh ha´´ens if pushing the keys.
When I press the drying cycle only, after I hit the start button, I hear the valve for the air opens, the air pump never comes on. I tried the air pump by otself applying voltage directly and it works fine. So I amthinking maybe a short circuti soemwhere??
I have also tried to run the IN-OUT test described in the service manual, but it will just not come on.
Hope somebody could help me. Thanks a lot

maybe burned relay / fusible resistor

An open circuit is more likely - trace the voltages through and see where they disappear.
Robert

Thank´s for oyur comments, I have been tracing the voltages, can´t find it yet. When I get the answer I will post it in case somebody could need sometime.

Start at the beginning where you know there are some - such as the power supply then to the contacts of the realy that you can hear working and so on. If there are none at the power supply then you have your answer.
Robert

Time to check out the circuit diagram!

Take a look at the line from J16 on the main control board (AJUNC-3) to the drying pump. I see a solid-state relay (I also notice there is a fuse before the pump, BTW)!

I would say that "hearing the air valve" (43) is a Red Herring; the diagram shows it coming off JP12 (that is, not connected to the drying pump).


Try farther back - at the sold-state relay. Is it working?

On the other hand, I see that Juan is saying that the "In-Out test" won't run - which sounds a bit odd. Maybe he needs to confirm that (and if that is indeed the case, consider a system reset, fitting a new NVRAM, or whatever). Final thought - and it may sound like a daft question - but I suppose that the "UP" button is working OK?

Thank you very much for your responses. I have been tracing voltages all over the places and finally found that the FUSE HOLDER was the problem, most of the times are the simplest things was makes big problems.

Monday I will run some tests and see if everyhting is working fine.

Happy weekend.

The fuse before the drying pump?

Nice fix! And thanks for telling us about it.

Yes, it was the fuse holder, the fuse was OK, and that is were I was getting confused. I´ve tried today a complete sterylization cycle with drying and worked fine. But there still a problem when trying to run only a drying cycle, it is not starting

Look again at your repair.

Try bypassing the fuse (fuse holder) - temporarily, of course - or better still bypass with a jumper containing another fuse of suitable rating.