SP540-V Temperature too low error

Modtour4

New Member
Hope someone can help out.

Before the error: the B/C was printing perfectly but the M/Y wasn't printing at all. Found out the M/Y fuse kept blowing everytime I turned on the subpower. I sent the main board out and had the problem fixed. Once I got it back, I installed it and hooked everything back up. Again, only B/C was printing. Switched the B/C head with the M/Y head and it printed. I then switched the cables and started getting the "Temperature too low" error.

I then put the B/C head back in and still got the error message.

I then installed a new B/C head and a new M/Y head. I replaced all 4 cables with new cables and still get the error message.

Any ideas what to check/do next? I have a fairly large print job coming up and need to get this back running.

Thanks in advance for any help

Russ
 

Solventinkjet

DIY Printer Fixing Guide
Usually when a head fuse blows, it's a short in the head cables but since those are new it's could be damage to the terminals either on the head or the slider board. Head temperature too low means either the room is too cold or the head is not connected properly so it's not getting a reading from the head thermistor.
 

Modtour4

New Member
Usually when a head fuse blows, it's a short in the head cables but since those are new it's could be damage to the terminals either on the head or the slider board. Head temperature too low means either the room is too cold or the head is not connected properly so it's not getting a reading from the head thermistor.

Thanks for the quick reply.
The temperature of the room is warm. Just did a heater check through the service menu and was able to bring up the temperature to where it was warm to the touch on both the print and dryer heater. I also changed the Print Carriage Board that the cables connect to. Changed the head ranks of both the new boards.

Thanks again
 

Solventinkjet

DIY Printer Fixing Guide
Thanks for the quick reply.
The temperature of the room is warm. Just did a heater check through the service menu and was able to bring up the temperature to where it was warm to the touch on both the print and dryer heater. I also changed the Print Carriage Board that the cables connect to. Changed the head ranks of both the new boards.

Thanks again

The temperature it's referring to is in the print head not the platen heaters. It tells the printer if the environment is suitable for printing. If it says it's too hot, it's usually a short in the head circuit. If it says it's too cold, it's usually a bad connection in the head. I would double check all the cables to make sure they are plugged in perfectly. If everything looks good, there might be some electrical damage somewhere causing the issue but that is hard to pinpoint unfortunately. I'm not a Roland expert though. Maybe Jim Hancock or Joe House has an idea.
 
I then switched the cables and started getting the "Temperature too low" error.
How did you switch the cables? Did you switch them like the attached diagram or did you switch the cables on the one head, i.e., move the left cable to the right side of the head and vice versa? The attached diagram is the only acceptable way to switch cables. You don't want to swap cables on the same head. The 2 cables on a single head carry different data, signals, voltages, etc., so never swap on a single head, only from head to head as shown in the attached pic. Otherwise, you can cause damage to the mainboard.
 

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Modtour4

New Member
How did you switch the cables? Did you switch them like the attached diagram or did you switch the cables on the one head, i.e., move the left cable to the right side of the head and vice versa? The attached diagram is the only acceptable way to switch cables. You don't want to swap cables on the same head. The 2 cables on a single head carry different data, signals, voltages, etc., so never swap on a single head, only from head to head as shown in the attached pic. Otherwise, you can cause damage to the mainboard.

I'll be honest with you...I really don't remember. I think the second time I tried printing, I left the cables connected to the Print board but switched the cables on the heads. Is there a way to check anything on the mainboard or do I just have to get a new one?

Thanks for your help

Russ
 
The fuses and output transistors can be checked with a multimeter. However, blown fuses and shorted transistors don't typically give you this error. If the ribbons were crisscrossed on the same head, it likely damaged other circuitry on the mainboard, which would be difficult to diagnose and repair. Where are you located?
 

Modtour4

New Member
The fuses and output transistors can be checked with a multimeter. However, blown fuses and shorted transistors don't typically give you this error. If the ribbons were crisscrossed on the same head, it likely damaged other circuitry on the mainboard, which would be difficult to diagnose and repair. Where are you located?

Jim,
I am located in Mystic CT.

Looks like I need a new mainboard! $$$$$$$$

Russ
 
Unfortunately, it's kind of looking that way. If you did crisscross the ribbons on the K/C head itself, then you most likely blew the head temp sensing circuit, in addition to who knows what. As an example, the schematics show contact 13 on the connector one side of the head being the head temp, but contact 13 on the other connector being ground, and contact 21 on one side being supply voltage and contact 21 on the other connector being ground. Hopefully it did not damage the print heads themselves, but that is a possibility, which I know you do not want to hear. You can get a new board from China for $1300-1400, but it will most likely be an empty board, meaning no firmware, etc, so it would need to be programmed. Roland has 2 in stock, which most likely have the firmware, but I would need to verify that. However they are around $1700, but you know what you are getting. And if it was my machine, I would replace both heads to be sure one of the heads isn't damaged and could possibly damage the replacement main board. You could also send it to whoever repaired it before, if they can go further then repairing the output transistors. Based on your original post, I suspect your m/y head was toast to begin with, as it most likely blew the fuse and maybe a transistor on the channel group to begin with and again when you got it back. Did the repair people tell you what they fixed? That would be useful to me to know to guide you any further.
 

Modtour4

New Member
Unfortunately, it's kind of looking that way. If you did crisscross the ribbons on the K/C head itself, then you most likely blew the head temp sensing circuit, in addition to who knows what. As an example, the schematics show contact 13 on the connector one side of the head being the head temp, but contact 13 on the other connector being ground, and contact 21 on one side being supply voltage and contact 21 on the other connector being ground. Hopefully it did not damage the print heads themselves, but that is a possibility, which I know you do not want to hear. You can get a new board from China for $1300-1400, but it will most likely be an empty board, meaning no firmware, etc, so it would need to be programmed. Roland has 2 in stock, which most likely have the firmware, but I would need to verify that. However they are around $1700, but you know what you are getting. And if it was my machine, I would replace both heads to be sure one of the heads isn't damaged and could possibly damage the replacement main board. You could also send it to whoever repaired it before, if they can go further then repairing the output transistors. Based on your original post, I suspect your m/y head was toast to begin with, as it most likely blew the fuse and maybe a transistor on the channel group to begin with and again when you got it back. Did the repair people tell you what they fixed? That would be useful to me to know to guide you any further.

Hi Jim,

I was afraid of that, so I ordered a new board. How would I go about installing the firmware? The people that repaired it told me "It wasn't a major short - so we would not expect the head to cause the damage to the board". I do know they soldered in two fuse holders so I have a way to replace the fuse if it blew again instead of having to solder in a new one. The problem happened before I put in the new heads or new cables, so I'm hoping that won't be a problem.

Again, if you could give me any help with installing the firmware when the new board comes in, I'd really appreciate it.

Thanks for all the help/advice

Russ
 
Sure, I can help you. You will need a crossover network cable. Let me know when you expect to receive the board, as I will be out of town next week.
 

Modtour4

New Member
Sure, I can help you. You will need a crossover network cable. Let me know when you expect to receive the board, as I will be out of town next week.

Thanks Jim,
It doesn't look like the board will be here til next week. I ordered a crossover cable, is there anything else I will need?

I really appreciate your help

Russ
 
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