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.

Thanks for the advice, let´s see how it goes. I have already changed the Fuseholder for a new one, and is working for the other cycles, only if a choose the drying cycle is the problem

Going crazy with this unit. I start the day and choose the drying option, the unit blocks itself and does nothing, so just turn it off. COme back again next day in the morning, turn the unit ON and it starts the drying cycle on itself, its like it is picking up what did not do the day before?

Maybe a defective EPROM?

Have you had a good dig around the solid-state relay that controls the drying fan? Looking at the diagram, that is (should be) the only way the drying fan gets energised.

Yes, the SSR are working perfectly, and as I say, it only doesnt work when you select a Dry Only program, but the drying pump works when the drying is part of a Sterilization cycle.

..any development?

Waiting on a new EPROM, hope this will solve the issue.

...let us Know.

Just replaced the Eprom, now the crying cycle works very well. I recalibrated the income water time which was 140s to 40s, but now 2 new problems arised, one is with the water, the unit starts the water pump for the set time, stops 1s then turn on again the water pump for 20-25s more. The other problem is that the unit reaches 134° but pressure seems to be a little down for that temp. and once the temp is reached, it doesnt go into sterilization time????
When the cycles are for 121° is working just fine. Going crazy with this unit.

How come Eprom is the problem? maybe there's something else or there's a reason why?

For the lack of pressure I found a small crack in the door gasket, we will see how it goes after we replace it.

Ariel, perhaps do you have the user or service manual for a Maquet HS22K5?

No need to mention on me, if I ever have I'll send it immediately.

Have you ask our friend google?

Yes, google doesnt have it, very difficult ot find it.

My unit is now working fine on the 121°C programas.
When we choose the 134°C programs, temp and pressure rises up to 124°C in a correct relationship, then it starts to fall, temp. reaches 134 but pressure is around 30psi below what it should be, so the unit gives a too long time error, as I imagine, is waiting for the pressure to be the correct one. I will try to look for pressure leaks, or bad valves may be??? Any toughts are welcome.

Door seal?

Clog? bad valves?

Dear friends: Finally solved all the issues with this unit, so first of all thank you all for your colaboration and always good will. Problems found:

1. No drying cycles were taking place, and if chosen only a dry cycle the unit will block.

Solution: 1. Damage fuse carrier
2. Defective memory on the main PCB AJUNC3

2. Lost of pressure: 1. The seal on the door was with a crack, changed it for a new one.
2. Exhaust Valved worm out, changed with a new one.

3. Unit now working OK

Best regards to all of you.

What happened? how come the memory on the PCB got deffective?

I dont know. We took this unit from the customer after they had a bad experience with the technical service of Tuttnaer representative in the country. Maybe some kind of electrical pike??

There's a lot of them about here, too.