Page 4 of 5 FirstFirst ... 2345 LastLast
Results 31 to 40 of 49

Thread: Jobo CPP2 Motor Malfunction

  1. #31

    Join Date
    Dec 2014
    Location
    Iowa City, Iowa
    Posts
    978

    Re: Jobo CPP2 Motor Malfunction

    Quote Originally Posted by jkorpi View Post
    Hey.
    Great response. Thanks for your thoughts.
    So, I have unhooked the motor from the motor board and then powered up the unit. The fuse still blew without the motor hooked up, so that tells me it's not the motor. I hooked the motor up to a variable DC power unit and was able to give the motor the exact DC power required to turn the motor, and VIOLA! It turned. So the motor seems good to go. I must say, the motor is hard to turn by hand. I can turn it, but it takes some umf!
    My next step is taking the speed switch out and testing it. I'm not sure how to hook it up to a light or what I should do to test it, but I'm sure I'll find some video on the world wide web.
    I'll let you know how it goes.
    Cheers,
    Jim
    If you can hook up your separate DC power supply through the switch it should regulate the speed of the motor. I have a suspicion it's something on the 110V side that's blowing the fuse.

  2. #32
    Jim Korpi
    Join Date
    Jan 2016
    Location
    Athens, Ohio
    Posts
    15

    Re: Jobo CPP2 Motor Malfunction

    Quote Originally Posted by Duolab123 View Post
    If you can hook up your separate DC power supply through the switch it should regulate the speed of the motor. I have a suspicion it's something on the 110V side that's blowing the fuse.
    So I bypassed the other boards and powered up the motor board independent of the other two switch boards, and the motor spun just fine without blowing the fuse. So there must be some issue coming from the other boards. Any tips to finding an issue with the switch or the board the switch is on?

    Thanks,
    Jim

  3. #33
    Jim Korpi
    Join Date
    Jan 2016
    Location
    Athens, Ohio
    Posts
    15

    Re: Jobo CPP2 Motor Malfunction

    Quote Originally Posted by mpirie View Post
    Ah, ok Jim, i read your post wrong.

    As Duolab says, the speed knob is just a dimmer, allowing more or less current to the motor to change it's speed, though it also has a switch so that the motor can be turned off completely.

    Blowing fuses is a sign of a short. First place to start is to make sure all the wires are in the correct places....hard to do when we can't get a circuit diagram. Did you check the heating element for resistance/short?

    Mike
    Hey Mike.
    So I brought power to the motor board independent of the switch board... and the motor ran just fine without blowing a fuse. So there must be a short coming from the switch boards. I'm not sure how to test the heating element for resistance or a short. The heating side of things seems to work just fine. Any thoughts on where to check on the switch board for shorts...?
    Curiously,
    Jim

  4. #34

    Join Date
    Aug 2005
    Location
    Illinois
    Posts
    33

    Re: Jobo CPP2 Motor Malfunction

    Quote Originally Posted by jkorpi View Post
    Hey Mike.
    So I brought power to the motor board independent of the switch board... and the motor ran just fine without blowing a fuse. So there must be a short coming from the switch boards. I'm not sure how to test the heating element for resistance or a short. The heating side of things seems to work just fine. Any thoughts on where to check on the switch board for shorts...?
    Curiously,
    Jim
    To measure resistance for shorts, etc. get yourself a cheap DVM (digital volt meter). It'll cost you $10 (or more) and will measure voltage, resistance and current among other things. To check the heater for a short, unplug/detach the element from its control board. Measure the resistance across the two leads. Ohms law (R=V**2/P) tells you that for a 1000W element rated for operation at 120 volts the resistance should be ~15 ohms. For a 500 watt element ~30ohms.

  5. #35

    Join Date
    Dec 2014
    Location
    Iowa City, Iowa
    Posts
    978

    Re: Jobo CPP2 Motor Malfunction

    Quote Originally Posted by jkorpi View Post
    Hey Mike.
    So I brought power to the motor board independent of the switch board... and the motor ran just fine without blowing a fuse. So there must be a short coming from the switch boards. I'm not sure how to test the heating element for resistance or a short. The heating side of things seems to work just fine. Any thoughts on where to check on the switch board for shorts...?
    Curiously,
    Jim
    If the heater is working fine, pump running display lighting up. The motor is running. Next step is try to investigate the speed switch. The speed switch clicks on then is smooth like a dimmer. I would look at the speed switch. Could it be switching 110V AC to the motor board, and separately be varying the voltage to the motor??

    Get a decent multi-meter, I have one, digital readout that I bought for 25-30 bucks. Look down steam of the fuse something is going to the ground, sending so much current through the fuse that the filament goes puff. That fuse is saving the board. Is the fuse on line voltage or 24V DC? If you could narrow it down Catlabs can probably provide you with a part. I replaced the speed switch in mine several years back, mine just broke. Omer Hecht CatLABS supplied me with a not OEM switch, because the original was unavailable, was a bit of a challenge for me. You need to just keep looking or try to find a old school radio and TV repair kind of person. These machines are antique, even if you know exactly what is wrong the component may not be available. Don't give up.

  6. #36
    Jim Korpi
    Join Date
    Jan 2016
    Location
    Athens, Ohio
    Posts
    15

    Re: Jobo CPP2 Motor Malfunction

    Quote Originally Posted by Duolab123 View Post
    If the heater is working fine, pump running display lighting up. The motor is running. Next step is try to investigate the speed switch. The speed switch clicks on then is smooth like a dimmer. I would look at the speed switch. Could it be switching 110V AC to the motor board, and separately be varying the voltage to the motor??

    Get a decent multi-meter, I have one, digital readout that I bought for 25-30 bucks. Look down steam of the fuse something is going to the ground, sending so much current through the fuse that the filament goes puff. That fuse is saving the board. Is the fuse on line voltage or 24V DC? If you could narrow it down Catlabs can probably provide you with a part. I replaced the speed switch in mine several years back, mine just broke. Omer Hecht CatLABS supplied me with a not OEM switch, because the original was unavailable, was a bit of a challenge for me. You need to just keep looking or try to find a old school radio and TV repair kind of person. These machines are antique, even if you know exactly what is wrong the component may not be available. Don't give up.
    Duolab, thanks for the encouragement and thoughts.
    I just started really investigating the switch board itself. I've attached a schematic of the board. Basically I checked the resistors and capacitors around the switch to see if they were up to snuff. It seems they are. I'm learning a heck of a lot about electronics with this machine. I'm trying to tell my wife that she needs to think of this as a cheap electronics class. That's how I'm staying sane. Sort of. Thanks for the "don't give up", because after last night of removing resistors and testing them I almost said, "FORGET IT!!!" But I have about 25 rolls of 120 film I refuse to send in the mail to have someone send them back with fingerprints all over them and signs of weak chemistry.

    So...the switch is something I feel like must have something to do with this issue. I've tested everything down the line and tried to test the switch, but I really don't know the best way to do this. If you've replaced your switch you know what I'm dealing with. I could send a photo of it as well...

    Thanks again for your thoughts. I'll get this if it kills me...cpp2_switch_board.pdf

  7. #37

    Join Date
    Feb 2008
    Location
    The Highlands of Scotland
    Posts
    243

    Re: Jobo CPP2 Motor Malfunction

    I doubt it is any of the switches TBH. Looking at the CPP2, the switches are: main power on/off, pump on/off, speed control with on/off. If any of the switches had shorted, then the controlled item (power, pump, motor) would come on and not switch off.

    Something is creating a short that is allowing more current to be drawn from the supply side than the fuse can/should handle. Semi-conductors like the power transistors rarely short as they'd explode, hence the question about the heater element. As far as I can see, only the motor, the switching relay or the heater element can draw enough current to blow a fuse.....or the wiring has been changed and introduced a short.

    Mike

  8. #38

    Join Date
    Dec 2014
    Location
    Iowa City, Iowa
    Posts
    978

    Re: Jobo CPP2 Motor Malfunction

    Quote Originally Posted by mpirie View Post
    I doubt it is any of the switches TBH. Looking at the CPP2, the switches are: main power on/off, pump on/off, speed control with on/off. If any of the switches had shorted, then the controlled item (power, pump, motor) would come on and not switch off.

    Something is creating a short that is allowing more current to be drawn from the supply side than the fuse can/should handle. Semi-conductors like the power transistors rarely short as they'd explode, hence the question about the heater element. As far as I can see, only the motor, the switching relay or the heater element can draw enough current to blow a fuse.....or the wiring has been changed and introduced a short.

    Mike
    Could the heater be "leaking" current somehow, or pulling too much current that when the motor starts up it takes it over the limit? I'm sure Omer Hecht at Catlabs could fix it if he had the parts. But where's the challenge in paying a professional when this is so much fun

  9. #39

    Join Date
    Dec 2014
    Location
    Iowa City, Iowa
    Posts
    978

    Re: Jobo CPP2 Motor Malfunction

    Quote Originally Posted by jkorpi View Post
    Duolab, thanks for the encouragement and thoughts.
    I just started really investigating the switch board itself. I've attached a schematic of the board. Basically I checked the resistors and capacitors around the switch to see if they were up to snuff. It seems they are. I'm learning a heck of a lot about electronics with this machine. I'm trying to tell my wife that she needs to think of this as a cheap electronics class. That's how I'm staying sane. Sort of. Thanks for the "don't give up", because after last night of removing resistors and testing them I almost said, "FORGET IT!!!" But I have about 25 rolls of 120 film I refuse to send in the mail to have someone send them back with fingerprints all over them and signs of weak chemistry.

    So...the switch is something I feel like must have something to do with this issue. I've tested everything down the line and tried to test the switch, but I really don't know the best way to do this. If you've replaced your switch you know what I'm dealing with. I could send a photo of it as well...

    Thanks again for your thoughts. I'll get this if it kills me...cpp2_switch_board.pdf
    The last revision to that drawing is in 1983. As long as it's just individual components there's hope. I would try over on Photrio formerly APUG as well. WITHOUT THE MOTOR DOES THE PUMP RUN AND DOES THE HEATER MAINTAIN A CONSTANT TEMP, LIKE 38C? If the heater is overheating or not heating could be another thing entirely.

  10. #40

    Join Date
    Feb 2008
    Location
    The Highlands of Scotland
    Posts
    243

    Re: Jobo CPP2 Motor Malfunction

    You can disconnect the motor and check the heater element raises the water temp. Pull the green and black spade terminals from the main board.

    You can also isolate the heating element (but more carefully, as they will be mains voltage) and leave the motor connected to see if the motor runs.

    If you get a result in either test, you will then be able to narrow down what is causing the excessive current draw that blows the fuse.

    Another thought just came to me. If the fuse you've fitted blows quickly, then you could try an "anti-surge" fuse of the same value in its place. "AS" fuses have what looks like a coiled spring inside which can tolerate a slightly higher current draw at startup, thus avoiding the current surge to get things like motors started, but still provide the same level of fuse protection.

    Mike

Similar Threads

  1. Jobo CPP2 motor is not turning on. How to repair?
    By mynewromantica in forum Darkroom: Equipment
    Replies: 15
    Last Post: 12-Dec-2019, 07:32
  2. Jobo CPA2 / CPP2 Motor Upgrade
    By yelmarb in forum Darkroom: Equipment
    Replies: 1
    Last Post: 9-Sep-2018, 01:39

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •