Printer works but there are mistakes on pages

[Tnet]

I have LaserJet 4 Plus, WIN XP, WL500b original firmware. When I print it works perfect but on some pages it makes terrible mistaken symbols or empty places.
Is it problem of router, printer driver or RAW mode? (I have tried several print drivers)

Any advices?
Thank you.

[Oleg]

Wild guess. Is your printer connected via LPT port? If so, try shorter cable.

[Tnet]

When I connect LPT cable to PC everithing is OK.->Cable is OK Router makes errors.

[Oleg]

Yes, but ASUS wl500g does not have many things which PCs has - like the shielding, ground wire and so on.
The biggest reason for "mistakes" is the noise, not the software.

[Technik]

When I connect LPT cable to PC everithing is OK.->Cable is OK Router makes errors.

So what's the length of your printer cable? If it's longer than 2 meters, I would also recommend to use shorter one.
Another solution could be to replace 4k7 pull-up resistors inside the router...

[Tnet]

The cable was 3m long I have replaced it with better shielded 2m long one. I didn't thought that router is more affected by noise. I hope it will be perfect now. Thank you