Jobo ATL-2 rebuilding project

[AgX]

No, by lack of an Eprom in the design of my Jobo... The ATLs do not have any competition at the current Jobo range, so I do not see a reason to be reluctant, in case the respective knowledge is still in th house.

More so as they stopped referring to independent service providers as in the past.

 

[Raoul Butler]

I can ask again, the state of play for me is, my machine is nuts and bolts at the moment as I am waiting for some parts from the USA. When they arrive I can ask. It seems there are more than one EPROM configurations and some other chip sets have a mix of options. When I have installed the new parts I will contact JOBO, best not to be a annoying and tax my relationship with JOBO.

If you do ask them Id be interested in hearing what the outcome was.... Thanks for your interest.

 

[ic-racer]

If I can find a good home for one, meaning someone who will ACTUALLY take care of the unit, being that I am a little protective of them then I think I could sell one.. I do not need 3 ATL's in my basement.. sitting on my shelves and these will better serve the analog photo community. They wouldn't be bargain basement priced though and not because of greed but because of all the parts that needed to be hunted down and only a partial consideration of the labor hours it took to bring them back to life..

Ok. The reason I ask, is when I was re-doing my darkroom over 10 years ago now, A free broken ATL came up. I contemplated the drive to get it and attempt repair. It does seem that in the intervening years, JOBO came out with a new unit and my older CPP-2 is still working fine.
But it would be nice to not have to pour the chemicals.

 

[Greg Moscow]

Hello Greg
How is Moscow today?

I have an EPROM that I believe has dropped out, I managed to arrange a replacement logi-board but there seems to be a few variations. Do you have the binary code for the EPROM? This is my board for an ATL3 (early model) The number on the chip is 3902, does that mean anything?

Cheers Raoul

Hello Raoul.
3902 is version of binary code. I have 3902 code of 27c256 IC. Can you read your EEPROM? I may compare with my copy. If it differ I can send to you right copy.

 

[Fred of Wisconsin]

I can ask again, the state of play for me is, my machine is nuts and bolts at the moment as I am waiting for some parts from the USA. When they arrive I can ask. It seems there are more than one EPROM configurations and some other chip sets have a mix of options. When I have installed the new parts I will contact JOBO, best not to be a annoying and tax my relationship with JOBO.

If you do ask them Id be interested in hearing what the outcome was.... Thanks for your interest.

Hi Raoul.. is there any chance that you could post a couple of images of your nuts and bolts project? I like to know that I am not alone in taking a processor down to the final rusted screw or nut to start a rebuilding project. When I do the rebuild I use all stainless materials. As the rebuilding goes forward that's when the electrical components come into play and that is when my hair gets grayer.. but I do not give up!

 

[nbagno]

Fred, do you know how do these ATL's determine that enough chemistry has been pumped? I've been troubleshooting an ATL-1, but it's not clear in the service manual language how the machine determines that the fill quantity set point has been reached. Does it use the fill sensors to feed back the quantity of chemicals filled? No mater what I set the fill quantity, it fills up to 700ml. I was sure the issue was going to be the BDC rotary switch that sets the fill amount, I've seen those fail but that wasn't it. I also replaced the IC that receives the BDC signal but that wasn't it. I do know that if it does not pump chemistry, the alarm will sound so it sounds to me like the fill sensors are working.

 

[Fred of Wisconsin]

Fred, do you know how do these ATL's determine that enough chemistry has been pumped? I've been troubleshooting an ATL-1, but it's not clear in the service manual language how the machine determines that the fill quantity set point has been reached. Does it use the fill sensors to feed back the quantity of chemicals filled? No mater what I set the fill quantity, it fills up to 700ml. I was sure the issue was going to be the BDC rotary switch that sets the fill amount, I've seen those fail but that wasn't it. I also replaced the IC that receives the BDC signal but that wasn't it. I do know that if it does not pump chemistry, the alarm will sound so it sounds to me like the fill sensors are working.

I do not have any experience with the ATL-1 but Jobo mostly followed the same process to the other series. I have found that ATL-2s rely on pump and water timing programed into the control board and I strongly think it is programed either into the CPU IC-1 or the IC-4 which is an 8 Bit programmable ram. The flow sensor's only job is to make sure a liquid of any type is being supplied to the drums. It doesn't matter if it is chemistry or water just that it is pumping something. The chemistry pumped via the air pump is based on the length of the chemical feed hose to tank 1 (being the shortest) and tank 6 being the longest then are fine-tuned with the fill quantity circuit board which adjusts the voltage being supplied to the pump by either slowing the pump down for less chemistry (less air pressure) or increasing the speed of the pump supplying more air to the chemical bottles.

Again I am not familiar with the ATL-1 circuity but if you replaced the IC that receives the BDC signal was that an off the shelf IC or was the program loaded into the IC either from a used part or from the removed chip? My advice would be to reinstall the original IC and since you replaced the rotary switch start testing again. Since you mention that it stops at it is stopping at 700ml that is most likely the amount programed into the IC's for the measurement test All the IC's are not generic to these processors, they are programed for specific steps and those are mostly timing steps. I have an early ATL-2 board that I use as a donor board I will pull it out of storage and take a look at the chips and circuits later today or tomorrow. You should be able to silence the alarms for testing purposes by jumping the 2 flow sensor leads to fool the processor because the processor is looking for a completed circuit when it is monitoring the flow cycles. I use that trick with ATL-2s what don't have the ability to shut the flow sensor off when I a am bench testing circuits for troubleshooting.

I do not have any schematics for the ATL-1.

 

[nbagno]

I do not have any experience with the ATL-1 but Jobo mostly followed the same process to the other series. I have found that ATL-2s rely on pump and water timing programed into the control board and I strongly think it is programed either into the CPU IC-1 or the IC-4 which is an 8 Bit programmable ram. The flow sensor's only job is to make sure a liquid of any type is being supplied to the drums. It doesn't matter if it is chemistry or water just that it is pumping something. The chemistry pumped via the air pump is based on the length of the chemical feed hose to tank 1 (being the shortest) and tank 6 being the longest then are fine-tuned with the fill quantity circuit board which adjusts the voltage being supplied to the pump by either slowing the pump down for less chemistry (less air pressure) or increasing the speed of the pump supplying more air to the chemical bottles.

Again I am not familiar with the ATL-1 circuity but if you replaced the IC that receives the BDC signal was that an off the shelf IC or was the program loaded into the IC either from a used part or from the removed chip? My advice would be to reinstall the original IC and since you replaced the rotary switch start testing again. Since you mention that it stops at it is stopping at 700ml that is most likely the amount programed into the IC's for the measurement test All the IC's are not generic to these processors, they are programed for specific steps and those are mostly timing steps. I have an early ATL-2 board that I use as a donor board I will pull it out of storage and take a look at the chips and circuits later today or tomorrow. You should be able to silence the alarms for testing purposes by jumping the 2 flow sensor leads to fool the processor because the processor is looking for a completed circuit when it is monitoring the flow cycles. I use that trick with ATL-2s what don't have the ability to shut the flow sensor off when I a am bench testing circuits for troubleshooting.

I do not have any schematics for the ATL-1.

Thanks Fred. The ATL-1 looks very similar to your atl-2. Here is the ATL1 service manual, and the spec for the chip I replaced, a rockwell R6522 VIA

 

[Fred of Wisconsin]

Got it .. thanks. How did you write the chip with the programing data?

 

[nbagno]

Got it .. thanks. How did you write the chip with the programing data?

Hi, I didn't. I just swapped it with one from a spare board. A different version board however.

 

[Grabn]

Did anyone make new controller for atl series?

 

[pwadoc]

Did anyone make new controller for atl series?

I've been considering it, but there is a lot of variation throughout the series. It would be possible to create a controller for the earlier ATL 1/2/3, and definition possible to create a controller for CPP/CPA heads (which is where I'm thinking of starting). The later ATLs are much more complex and have a lot less experience working with them.

 

[nbagno]

Fred, do you know how do these ATL's determine that enough chemistry has been pumped? I've been troubleshooting an ATL-1, but it's not clear in the service manual language how the machine determines that the fill quantity set point has been reached. Does it use the fill sensors to feed back the quantity of chemicals filled? No mater what I set the fill quantity, it fills up to 700ml. I was sure the issue was going to be the BDC rotary switch that sets the fill amount, I've seen those fail but that wasn't it. I also replaced the IC that receives the BDC signal but that wasn't it. I do know that if it does not pump chemistry, the alarm will sound so it sounds to me like the fill sensors are working.

I did fix this, but I never update this post. The issue with not enough fill was that I pinched the hose that goes from the air pump to the air distributor. It was pitched when I put the head back on the processor for the umteenth time.

 

[CoastalBoy]

@Fred of Wisconsin perhaps you can help, recently brought an ATL-2 online at our lab. We've been using it the last few days with some issues, namely 4/6 of the supply lines aren't pumping properly. Two of which, I've managed to get working once or twice by applying some teflon tape around the air and chemical hose fittings where they meet with the bottles. I assume first step would be to replace the bottle o-rings, do you happen to know of a good source for those?
Also, recommendations on best kinds of hoses to use as replacements, I plan to do that next if the o ring replacements don't solve things.
Appreciate your help in advance, happy to have saved another old processor from the retirement!
- Stephen

 

[Fred of Wisconsin]

@Fred of Wisconsin perhaps you can help, recently brought an ATL-2 online at our lab. We've been using it the last few days with some issues, namely 4/6 of the supply lines aren't pumping properly. Two of which, I've managed to get working once or twice by applying some teflon tape around the air and chemical hose fittings where they meet with the bottles. I assume first step would be to replace the bottle o-rings, do you happen to know of a good source for those?
Also, recommendations on best kinds of hoses to use as replacements, I plan to do that next if the o ring replacements don't solve things.
Appreciate your help in advance, happy to have saved another old processor from the retirement!
- Stephen

Good morning Stephen, First off thank you being a "rescuer" of a Jobo ATL-2. I have manage to rebuild a total of 5 in the past two years and 3 are back processing film once again. Regarding your issue with the chemical pumping issue. Without knowing the actual processor condition it is a hard item to get to a short recommendation. Knowing how old these processors are and how most have been kept and stored I would run a air pumping test even before starting to fix an issue especially since it is effecting most of the processors operation. More than likely the issue is more complex than an air connection at the chemical bottles. The issue is most likely with the air distributor. The air pump sends the air to the distributor which directs the air to the process bottle that is in the development step. If you wish I will be able to go into more depth but because of the amount of information and document pages we will need to take this outside of the forum.

 

[Brian Rotsten]

Fred of Wisconsin, I just bought an ATL2 that has been in storage for 25 years. When I powered it on, the display came on very briefly and then went out. Nothing works other than the cooling fan. The number 3 fuse is blown. I found two service manuals on the web, both missing the schematics. Do you by chance have copies of the schematics and any pointers what direction to look for the fuse blowing?

 

[AgX]

My first thought is a stuck motor, resulting in a fuse blowing. But that should not lead to the display going off.

 

[Fred of Wisconsin]

Fred of Wisconsin, I just bought an ATL2 that has been in storage for 25 years. When I powered it on, the display came on very briefly and then went out. Nothing works other than the cooling fan. The number 3 fuse is blown. I found two service manuals on the web, both missing the schematics. Do you by chance have copies of the schematics and any pointers what direction to look for the fuse blowing?

Good morning Brian, as a matter of fact I have seen that issue on a unit I rebuilt and put back into use. I traced the issue to 2 caps that failed on the interface board (PN 94015). I am attaching a pic of the area. I have found that this fuse can also be blown from a circuit pair on the power supply board. I will reach out in a more secure way to share some information with you.
Stay safe and healthy.

 

[AgX]

You mean a capacitator has blown just at/by powering up?

 

[pwadoc]

Here are the ATL-1 schematics that I have access to. http://ur.sine.com/temp/jobo-docs/ATL-1 Schematics.pdf

 

[Fred of Wisconsin]

You mean a capacitator has blown just at/by powering up?

Hi AG.. these processors are anywhere from 20 to 30+ years old now and yes any component can fail on power up. Regarding BR's question of have I ever seen that issue where the #3 fuse blows on powering up a processor was a direct issue that I experienced then had to trouble shoot and had to repair at a component level. The schematic I work off of was very helpful showing all the posible failure points. Caps can and often do fail as they age. Hope this helps.

 

[Brian Rotsten]

To follow-up my issue, with help from Fred I found that capacitor c27 on the interface board was shorted to ground and causing the fuse f3 to blow. I replaced it with an electrolytic cap I had on hand and the unit came back to life.

 

[AgX]

Your board looks pristine, especially not filthy. How could a capacitator got ground contact?

 

[Brian Rotsten]

Your board looks pristine, especially not filthy. How could a capacitator got ground contact?

Old electronics, especially capacitors can deteriorate over time.

"DIELECTRIC BREAKDOWN (SHORTS)
The classic capacitor failure mechanism is dielectric breakdown. The dielectric in the capacitor is subjected to the full potential to which the device is charged and, due to small capacitor physical sizes, high electrical stresses are common. Dielectric breakdowns may develop after many hours of satisfactory operation. There are numerous causes which could be associated with operational failures. If the device is operating at or below its maximum rated conditions, most dielectric materials gradually deteriorate with time and temperature to the point of eventual failure. Most of the common dielectric materials undergo a slow aging process by which they become brittle and are more susceptible to cracking. The higher the temperature, the more the process is accelerated. Chemical or aqueous cleaning may also have an adverse effect on capacitors (See Technical Bulletin #11 ).

Dielectric breakdown may occur as a result of misapplication or high voltage transients (surges). The capacitor may survive many repeated applications of high voltage transients; however, this may cause a premature failure."

 

[AgX]

Yes, I know. But your wording mislead me. A capacitator shortcuiting in itself not necessarily has contact to ground. That is why I thought of external shortcircuiting and wondered why then you exchanged the capacitator. Though the latter should have have led me onto the right track...

Did you not consider then to exchange all electrolytic capacitators on the board?