For some, loosing time is a bigger problem. For others, saving money is more important. You mentioned that it is good for the end user to have some information so that they can understand what options to try in order to solve the problem. I completely agree. In this particular case, it is very difficult to diagnose the problem.
I can say what I think is going on, but not the reason why.
From what piperpilot says, the unit starts up, recognizes the drives, begins the copy process, and stops at “62 meg”. The wytron 688 unit will copy into the memory cache first and then copy to the writers. The 688 memory cache is 64MB but the LCD will show 62MB when it is full and ready to write to the drives.
It sounds like, when piperpilot is copying DVDs, the unit stops after the memory cache is full and right before the unit is supposed to actually send the data to be burned to the DVD. No data is actually written to the DVD discs at all.
piperpilot has stated that different types of media was used, all with the same result.
The unit copies CDs correctly, using the same drives.
So the only difference is the DVD media, or the DVD master data.
Or the firmware might be corrupted.
Or some setting on the unit was accidentally changed.
At this point, the best advice I could give would be to reflash the firmware. Reflashing will also reset all of the settings to their defaults.
Piperpilot’s vendor should be able to provide the firmware, which can be burned to a CD and then used with the unit’s “update” function.
If Piperpilot cannot get the file from his vendor, then he could PM me.