Dan Brown Posted April 1 Report Share Posted April 1 What does it indicate when noritsu 2406 chemistry temperature read 40.95 degrees? This happens with cold chemistry in CD, BF, and Stb2. Stb1 and Stb3 are holding temp and reading 37.8. Quote Link to comment Share on other sites More sharing options...
Dave S Posted April 1 Report Share Posted April 1 (edited) If the temperature is going above the set value, it's either due to poor circulation (blocked pump etc) or a faulty heater control relay. Another cause can be a poor connection of the thermo sensor, the temperature will read lower than it actually is with a poor wiring connection, though this normally will trigger the operation of the safety thermostat when it gets to 42°C Edited April 1 by Dave S Quote Link to comment Share on other sites More sharing options...
Dan Brown Posted April 1 Author Report Share Posted April 1 Temperature is actually cold when it reads 40.95 and don't heat because of erronious temp reading. All 3 tanks started doing it at one time. Could there be a power supply issue? Quote Link to comment Share on other sites More sharing options...
Dan Brown Posted April 2 Author Report Share Posted April 2 at start-up, readings are already at 40.95 degrees with cold chemistry Quote Link to comment Share on other sites More sharing options...
Dave S Posted April 2 Report Share Posted April 2 Measuring voltages on the A/D circuit for the temperature probes would be a good place to start. Which model of machine is this? Quote Link to comment Share on other sites More sharing options...
Dan Brown Posted April 2 Author Report Share Posted April 2 (edited) Lps-24. PP-2406 Edited April 2 by Dan Brown Quote Link to comment Share on other sites More sharing options...
davidlam Posted April 2 Report Share Posted April 2 see [ top left corner] of below diagram that all temperature sensors go to the paper processor Main board. I suggest clean the connector with contact cleaner and the Main board both surfaces Is dryer temperature shown ...also abnormal during start up ,, like chemicals ? If yes, I agree with Dave S that the "A/D conversion" has problem, I think A/D chip on the Main board is possibly defective . when problem started, was it found in the morning startup or a few hours after startup ? Quote Link to comment Share on other sites More sharing options...
davidlam Posted April 2 Report Share Posted April 2 see below the location of the paper processor "Main board" (being circled in red ). Had any technician adjusted anything on this Main board before problem came ? ? ? there is also one piece of NVRAM CHIP ( Non-Volatile Random Access Memory )on board to memorize all settings during power off. ) Quote Link to comment Share on other sites More sharing options...
davidlam Posted April 2 Report Share Posted April 2 From history, there had been 2 versions of Main board used in LPS-24Pro paper processor,,, is your PCB same with my photo version ? both versions Main board look different... easy to distinguish Quote Link to comment Share on other sites More sharing options...
Dan Brown Posted April 14 Author Report Share Posted April 14 David, thanks for jumping in. Sorry its taken a bit to get back to. Attaching a photo of the two boards, Not the same, but connector for temp sensors is in the same location. None of the temp readings match the true temp of the chemistry. Quote Link to comment Share on other sites More sharing options...
Dan Brown Posted April 14 Author Report Share Posted April 14 A little more background on the machine might help. Its been sitting idle for a year or so. The connectors for the CD and BF thermistors were a bit dirty, likely from chemistry and I have cleaned them. I've swapped around the thermistors into different tanks to test and don't think they are the problem as nothing changes in the condition. Also seems really unlikely all 5 would fail unless its something upstream. Where exactly is the A/D chip? Quote Link to comment Share on other sites More sharing options...
kodak_service Posted April 14 Report Share Posted April 14 Do the following experiments: 1. Turn off the developer temperature sensor and record the developer temperature reading on the display. 2. Short-circuit the developer temperature sensor and record the developer temperature reading on the display. Depending on the results, it will be possible to determine the cause of the problem. Quote Link to comment Share on other sites More sharing options...
kodak_service Posted April 14 Report Share Posted April 14 Also, please take a high-quality photo of the selected area Quote Link to comment Share on other sites More sharing options...
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