[sane-devel] Canonscan N 650U LIDE Scanner does not scan but makes terrible noise

[Gerhard Jäger]

Hi,

On Wednesday 28 August 2013 20:29:41 coxster dillon wrote:
[...]
> Most of time when I get noise 
> from my LIDE30 is when the head moves back for some alignment to the 
> sensor.  It seems to recover better or rather more often at higher dpi.

I'm a bit confused here (honestly I didn't follow the thread careful 
enough - sorry). You're talking about a LiDE30 - right?

This one is different to the N650U wrt settings of the motor...

> I
>  tried to power the scanner from my bench supply with success but only 
> very slight changes to my scan results.  I did measure the voltage at 
> the scanner down a 1.8M cable I got off ebay which had 24awg conductors 
> and it hovered around 4.6V.  I was concerned more about power since I 
> noticed when connected into a cable powered hub it actually makes the 
> noise nearly all the time and other times read errors are produced.  
> Interestingly the specifications for the scanner want a 1.5M cable or 
> less from canons website which means probably a very short cable since 
> they seem to come in standard lengths.

This point seems also to be important. I was not aware that Andrea has
connected its scanner to an USB hub.
[...]

Anyway, FYI Andrea is currently testing some tweaked motor settings
for the N650, maybew this is the way for you to go as well. The only
thing you need to do is to recompile the plustek backend with 
changed settings. Check the file plustek-usbdevs.c, around line 2330
you should find the following:

/** Canon N1240U/LiDE30 */
static HWDef Hw0x04A9_0x220E =
{
	0.72,   /* dMaxMotorSpeed */
	0.30,   /* dMaxMoveSpeed  */

IIRC MaxMotorSpeed is used during scanning, so if the scanner gets
stuck during a scan, try and lower that value. MaxMoveSpeed should
have influence on the speed while moving the scan head.

HTH,
 Gerhard