Drum don't stop on a Creo Lotem 800V2

[A_L_E_X]

I have a problem with a Creo Lotem 800V2. Randomly, when the exposure is at the end, the drum don't stop so that the plate can exit. I mean, in normal operation, the drum stops in about 2 seconds. Well, randomly, the drum stops after about 5 minutes and because of this i get an error message. Is there a braking system inside to stop the drum ? Where can i find it ? Someone have a service manual for this CTP ? Thank you in advance !

 

[A_L_E_X]

Now, the drum stops even when it's exposing plates. I mean , the plate is being exposed and the drum starts to slow. Only after the drum stops and i open any cover, i can unload the plates on drum. I don't think it's the encoder because the speed it's showed fine. The ctp just looses control over the drum. But i'll chech the wires just to make sure. Where is the encoder connected to ? To that electronic board near it ?

 

[PACH]

Now, the drum stops even when it's exposing plates. I mean , the plate is being exposed and the drum starts to slow. Only after the drum stops and i open any cover, i can unload the plates on drum. I don't think it's the encoder because the speed it's showed fine. The ctp just looses control over the drum. But i'll chech the wires just to make sure. Where is the encoder connected to ? To that electronic board near it ?

Alex,

do you get any error messages when the problem occurs with the drum?
Waht happens when you do a Drm Init from the Loading system?

 

[PACH]

Alex,
It could be the MCF board or the Drum POwer Supply ( ELMO) that is playing up.

 

[A_L_E_X]

When the problem occurs i get the message that the drum didn't stopped in the specified time. Also i get this message if i init the drum because the drum don't want to move. I cannot even rotate the drum from the hardware/drum/drum motor. The drum don't want to move unless i open and close a cover. Then if i click drum init, the drum initialize fine and i can unload the plate.
PACH, the drum power supply is in the back of the diode panel ? I have found 2 power supplies that were full of dust. Do you think that the problem could be from there ?

 

[PACH]

When the problem occurs i get the message that the drum didn't stopped in the specified time. Also i get this message if i init the drum because the drum don't want to move. I cannot even rotate the drum from the hardware/drum/drum motor. The drum don't want to move unless i open and close a cover. Then if i click drum init, the drum initialize fine and i can unload the plate.
PACH, the drum power supply is in the back of the diode panel ? I have found 2 power supplies that were full of dust. Do you think that the problem could be from there ?

Alex,
The Drum Power Supply is in the Distribution Box under the Power Distribution Board. You have to take the rear panel off to get to these parts. Do not touch anything inside before disconnecting the 3 phase. The MCF board is in the Electronics crate.
Let me know the exact error messages that you receive.

 

[A_L_E_X]

The distribution box is that box with automatic fuses on it where the power cable goes in ? Where is that electronic crate where i can find the MFC board ?

 

[A_L_E_X]

When the problem occurs i get the following messages :
Drum Motor Goto speed task timeout.
The task Drum Motor Go Speed failed.
The task Unload Manager task failed.
Can't unload Plate->Plate on drum exist.

 

[PACH]

When the problem occurs i get the following messages :
Drum Motor Goto speed task timeout.
The task Drum Motor Go Speed failed.
The task Unload Manager task failed.
Can't unload Plate->Plate on drum exist.

Hi Alex,

Please check and adjust if you can the following:


Check that 5.1V VCC provided from PS in E-box reaches MCF board.
This is the last board that receives the power from the PS
The PS (5.1V) is located at bottom of E-Box.
There are two T.P. on the MCF board: GND and +5v
It is not very easy to get to the POT to afjust this.
Remove the lower rear pannel and you will see with a torch the POT inside the PSU under the Electronics box.
Adjust this to 5.1v.
If all tis fails thyan it is the MCF or the Drum PSU. ( ELMO)
Good luck

 

[A_L_E_X]

I've noticed that if the air is cooler, the problem appears rarely. Might be the temperature of the power supply ? Where is the MCF located exactly ?

 

[PACH]

I've noticed that if the air is cooler, the problem appears rarely. Might be the temperature of the power supply ? Where is the MCF located exactly ?

Alex,
Open the RHS door of the Lotem where you will find the Electronics crate.
The MCF card I think is the second PCBoard from the top.
On the MCF board you will find the TestPoints ( Ground GDN and +5V)
The Power Supply is at the bottom of the Electronics Crate.
The POTentiometer can be accessed from the RHSide of the Power Supply
You might need a torch to see this POT and a long thin screwdriver to adjust it
Be carefull that you do not short someting out while you try and adjust
You need a DigitalVoltMeter to measure the voltage on the MCF card which should be 5.1v
Check for the 5.1v before doing anything
There is also a Fan that cools the Electronics crate, that is situated on the RHS of the crate
Make sure that the fan is still working and the air flow is not blocked by dirt.
I hope that you can make sense of all this and it will help you.
Good luck

 

[A_L_E_X]

The electronic crate is that big box where the main power cable goes in ? With automatic fuses on it ? The one on the bottom rear ? I am not familiar the terms you are using because i don't have any service manual or schematic. Just the instruction manuals.

 

[PACH]

The electronic crate is that big box where the main power cable goes in ? With automatic fuses on it ? The one on the bottom rear ? I am not familiar the terms you are using because i don't have any service manual or schematic. Just the instruction manuals.

Alex,

Open the front door of the Lotem ( froont cover that lifts up)

Now you will access to be able to open the RHS door that swings out

There you will see a big box with a cover on it. This is where you have the CD drive and
the Floppy drive( the big box where the mains power goes in is the Distribution Box. DO NOT GO IN THERE)
Remove the cover of the Electronics crate secured by two finger tight screws

This is where you will find the Electronics boards

 

[A_L_E_X]

I've measured the voltage of the MCF board and i have 5.09 V. Does it have to be exactly 5.1 V ? I've measured the voltage with a regullar multimeter that i believe it have some errors. Does it matter if i have 0.01 V less ? Also i've measured the main power voltage and i have 226 V. Could this be the problem ?

 

[PACH]

I've measured the voltage of the MCF board and i have 5.09 V. Does it have to be exactly 5.1 V ? I've measured the voltage with a regullar multimeter that i believe it have some errors. Does it matter if i have 0.01 V less ? Also i've measured the main power voltage and i have 226 V. Could this be the problem ?

Alex,
The voltage on the MCF looks OK.
Measure WITH CARE the 3 Phase voltage going to the Lotem. You should measure 120V Phase to GDN, or 208V Phase to Phase.
You can adjust the output voltage by moving the Taps at the input of the 3 phase transformer.
If you have to do this make SURE that the transformer is disonnected from the mains.

 

[A_L_E_X]

I've measured 226 V between phases. After i moved the input, i've measured 215 V.This is the maximum input. I think i can move the output to a lower voltage. I'll see if the problem persist with 215 V between phases.
P.S.Sometimes after the drum's speed began to fall, after few seconds the speed went back to normal and then after few seconds the speed fall again. This happened few times, not always. Maybe this can be helpful.

 

[A_L_E_X]

I still have the problem even with the lower voltage. But i've noticed that if i open a cover, close it back and then hit the stop button, the drum stopps. Maybe opening a cover and activating an interlock is like a reset to the system. How can i reset the system without open the cover ?

 

[PACH]

I still have the problem even with the lower voltage. But i've noticed that if i open a cover, close it back and then hit the stop button, the drum stopps. Maybe opening a cover and activating an interlock is like a reset to the system. How can i reset the system without open the cover ?

Alex,
I am afraid but you tried everything so far to get rid of your Drum Runaway.
I still advise that the problem is with the MCF or the Drum PSU (ELMO). You will have to try and find the wright combination of the two to get eliminate your problem. I know that you already tried to replace these parts before.

 

[Duncan Hyde]

I had this same problem once with my Lotem 400V we ended up replacing the MCF board
an putting in 2 additional grounding rods outside the building and making the breaker an independent ground not city grounding those boards are very sensitive, Hey also get a good UPS too

When the problem occurs i get the following messages :
Drum Motor Goto speed task timeout.
The task Drum Motor Go Speed failed.
The task Unload Manager task failed.
Can't unload Plate->Plate on drum exist.

Good Luck

 

[A_L_E_X]

Duncan Hyde, when you had the problem with Lotem 400, the problem appeared at every plate or from time to time ? How did you discovered that is the MCF board ? I've launched the diagnostic software and it didn't reported any problem. Also, if i install a UPS, can i start the UPS. then the CTP ? I wouldn't have any problem with communications between e-box and other systems ?