Roland VS-640 Printhead Test Caused Burn Smell – Now No Output

[Valerio9090]

Hello everyone,

I have a problem with my VS-640. I removed the current printhead to install another one in order to test if it was working or defective.

After installing it, I powered on the machine and got the error message: Temperature too high – 40°C. I then noticed a burning smell right away. I shut everything off, waited 10 minutes, removed the head, and reinstalled the old printhead.

When I powered it back on, the machine started up normally without any error messages.

However, when I tried to do a test print, nothing came out anymore…

Did I blow a fuse on the mainboard or on the carriage board?

Thanks best regards Gabriel

 

[Valerio9090]

Oh yes, on the defective printhead it was visible that the flat cables at the head were burned.

 

[Jim Hancock]

You need to check the fuses, output transistors and replace the burned cable, to start. And toss the old head that caused this...

 

[Valerio9090]

The head cables (flat cables) look fine. No discoloration visible.

The defective head is in the trash.

I’ll check and measure the fuses later.

Do you happen to know which ones it could be right away?

Thanks and best regards.

 

[Jim Hancock]

Oh yes, on the defective printhead it was visible that the flat cables at the head were burned.

Which cables were these? Not enough information to suggest which fuses. In these cases, you check them all, fuses and transistors.

 

[Valerio9090]

On this flat cable in the middle, two were burned. I don’t have a real photo right now.

 

[Valerio9090]

I’ll send a photo of the defective head later. You can see the burned spots there.

 

[Valerio9090]

Which cables were these? Not enough information to suggest which fuses. In these cases, you check them all, fuses and transistors.

 

[damonCA21]

I would really suggest getting a tech out to look at the printer. A burning smell with the new head means you could also have damaged that, but you need to find out why you smelled burning. There could be a power surge from somewhere else in the printer, and heads are too expensive to damage new ones.

 

[Valerio9090]

I just measured the carriage board and the F1 and F2 fuses on the mainboard.

• Carriage board fuse shows zero and a beep
• Measured all four ribbon cables, everything is fine
• Mainboard F1 and F2 show values that are too high, so the fuses are defective

What else should I check? Or is that enough?

 

[Valerio9090]

Here from the Mainboard Fuse

 

[Jim Hancock]

Now I understand about the burned traces. When you measure the fuses, I would suggest putting the meter on the 200 ohm scale. For the transistors, use the diode scale, but be sure to read the legs with the leads touching both ways, i.e., read with red and black, then switch and read the same legs with black and red.

 

[Valerio9090]

Now I understand about the burned traces. When you measure the fuses, I would suggest putting the meter on the 200 ohm scale. For the transistors, use the diode scale, but be sure to read the legs with the leads touching both ways, i.e., read with red and black, then switch and read the same legs with black and red.

Ok, thanks for the info ✌️

There are also some defective ones. I’ll go ahead and order a few as spares since I have two VS640 and one VS640i.

 

[Jim Hancock]

As you are in Europe, you may want to consider sending the board to Damon for repair.

 

[damonCA21]

You need to also find out why they have blown. If you just replace them you could get the same damage again or more parts damaged.

The transistors feed the signals to the head so you could damage your new head.

Ir is very unusual to get more than one transistor fail. They can fail with age but I have never seen more than one due to this. If more than one has failed along with the fuses blowing something has caused that so there are likely to be other shorts on the board from the burning you smelled.

I am happy to check and repair the board for you If you want to send me a message