Jobo ATL2 Problems

[DavePEI]

Hi Everyone:

I have received my ATL2 and as I knew when I bought it it is showing an air distribution error.

In diagnosing this problem, I checked for output from the air pump. Nothing. I then disconnected it, and found no 24 volts going into it. I then provided 24 vdc from an outside source directly to the pump, and it does operate.

So the problem appears to be an interruption of the 24 vdc going to the pump. Now, the next step I took was to check the fuses. There are three fuse holders in it Fuse1, Fuse 2, and Fuse 3. Only Fuse 1 and Fuse 3 was marked, and both their fuses are good. Fuse 2 is an unmarked empty fuse holder. So now, it is difficult for me to tell if the fuse 2 holder was merely used to close a blank in the board or whether indeed there is a missing fuse which should have gone in it (and if so, what amperage).

Other functions on the processor do work, e.g. to raise and lower the drum from the front panel switches.

A large part of my problem is my location - I live in Atlantic Canada, and to the best of my knowledge there are no longer any repair sites in Canada for Jobo's. The cost of postage to the US is approximately $100 to the US one way, so it would be impractical to send it to California, so I am going to have to diagnose and fix it myself.

The photo below shows the pump at the left front and behind it, the air distributor..

Does anyone know if the middle fuse is actually used in an ATL1, 2, or 2+ processor, and what value? Even more helpful would be a schematic or wiring diagram for the unit.

Can anyone offer advice?

Dave

 

[DavePEI]

I should have mentioned that when this machine is turned on, its display will quickly display a flashing "3", then a non flashing "7" then a decimal point along with a beep alarm.

Dave

 

[ZoneIII]

Hi Dave,

I see that you haven't received any responses to your question but I'm curious as to whether you have been able to fix the problem you were having. I ask because I'm thinking of buying an ATL-2 myself. If I do, I will open it up and see if it has a fuse in all three holders and, if so, what the amperage is of the one that is missing on your machine.

Tom

 

[DavePEI]

ATL-2

Hi Tom:

No, there are only two active fuses as I now know - the outside two. The center one is a dummy - just an empty fuseholder.

My problem went further than an air distribution problem. In addition to the air pump not running, the stepper motor which moves the arm on chemical reclaimation unit and the star gear in the air distributor also wasn't operating. It appears that the motor control IC (L293 motor control bridge) on the interface board was bad. I discovered that when I discovered a former owner had inverted one of the plugs from the solenoids and the air pump which had in turn taken out the IC. This IC performs the switching of the stepper motor, fill pump, and the hot and cold water solenoids.

The plug is designed to go in only one way, but somehow it was managed Needless to say, it is inserted correctly now.

I should have a replacement board next week and be able to confirm that its problems have been resolved. Afterwards if all is well, I will replace the IC on the original board, check it out, and save it for a rainy day.

It certainly made things more difficult living in Eastern Canada, and not wanting to spend a fortune in shipping the unit back to the U.S. and then back again. But it looks as though things are working out. So, hopefully some time next week, I will have the machine running (fingers crossed)

For those who saw my other postings about finding drums for use with the ATL2, I have found both a film and print drum, but still need one cog for the film drum. Thanks to all for your help and advice, and to Dave Smith for some excellent advice and long distance assistance.

Dave

 

[ZoneIII]

Dave:

It's nice to see that you found a new board. May I ask who you ordered it from? I'm still thinking of buying the ATL-2 that I mentioned but I am concerned about finding parts if I ever need to repair it. Jobo told me that parts are no longer available for it except for standard parts that it has in common with current Jobo processors. Jobo doesn't even have any info on their site for the machine anymore, as you know. An internet search for parts produced nothing. Considering all of that, I have to think carefully before buying this machine but if I knew of a source for parts, the decision would be easier. The seller claims that the machine functions fine and I have no reason to doubt him but I have also read that these machines are delicate and can be damaged just from the vibration during shipping so I have to consider that it may come DOA. I would really appreciate it if you could tell me where you found a board.

BTW, if I do buy the machine, it includes the manuals that go with it. If you don't have them yourself, I will be happy to copy them for you. But I have to first decide whether to buy it or not.

 

[DavePEI]

PM sent...

Dave

 

[DavePEI]

Jobo ATL2 fixed!

Hi All:

It was the interface control head board (94-017) which caused all the problems. As mentioned in a previous message, an IC on the board is used for the switching of the air pump, solenoids, and for the stepping motor - that IC was bad. The replacement board arrived today from Dave Smith, (email link to Dave on his web site below), at a reasonable price and I got it installed this evening solving the processor's problems.

I just wanted to thank Dave for his advice and for supplying the new/used board. As it was, it wasn't worth (to me) the cost of shipping it to the US to be serviced, and I have never shied away from diagnosing and servicing my own equipment. Thank goodness also for my prior knowledge of electronics.

The only thing standing in my way of using it now is waiting for clips for the arm to hold the tanks (as well as I still need one cog for the film drum I have).

I just wanted to mention this because I feel that Dave went above and beyond the call of duty in providing information which led to getting it going again, and for providing the replacement board.

Now I have the machine going, I am going to replace the bad IC on the old board, test it out for proper operation, then I will have a spare.

If you have a Jobo processor requiring some TLC, I highly recommend Dave.

Dave Smith's web site:

http://www.darkroomdoctor.com/Home_Page.php

Dave (Hunter)