My Pfaff 1475 CD stated batterie pile battery when machine is turned on.

Probably best to take it for service.

see if you can find out from this link.
How much does Pfaff 1475cd sewing machine Google Search

Hi
. whilst the 1475 is a great machine, it is getting on in years, and unfortunately, you may be experiencing the early stages of 'computer' / pc board failing. A trip to the technician may be you best option. If it is the pc board, sit down before asking the cost to repair it :)

Support site with phone number
http://www.pfaff.com/en-US/Support-and-Updates/Support

Machine Support

These instructions apply to PFAFF 1475 CD. They may also work for other machines.
If you have some advanced electronic repair skills and tools, check the following:
For 220 Volts models - there is a fuse next to the power input, make sure it is good. There is no such a fuse for 120 Volts model.
If the fuse is Okay, you have to get access to the main circuit board by removing the bottom cover.
Check the primary on the transformer for 120 V AC (220 V AC respectively). Check the secondary side for 5 V AC (luminescent display), 9 V AC (turns to 5 V DC by rectifier, 4700 micro farads capacitor and a 5 V regulator STI L387A) and 28 V AC (turns to 35 V DC by rectifier and 2200 micro farads capacitor.
Pay attention to two soldered round fuses in series with the secondary 9 V and 28 V - both should be good. On the big capacitors you should have 9 V DC and 35 V DC.
Common symptoms for bad small 22 micro farads capacitors next to the some of the IC's - there are 5 of these: These capacitors are in parallel with 5 V DC.
## All of the LEDs light up but the display is blank
## All of the LEDs light up, the display is blank, and after a minute no LEDs at all
## No LEDs nor display.
Replace ALL five 22 micro farads capacitors using a good desoldering pump or desoldering station!.
Enjoy your resurrected PFAFF 1475 CD machine!!!
I just did this procedure on my aunt's one (Made in West Germany around 1990).

here is a link for a manual--it should have the information in it that you need

Pfaff 1475 Creative CD Instruction Manual

Not sure if your model is the creative 1475. The closest I can find at a service website of Pfaff is 1473. Check if this is similar to your model and it shows where the balance wheel goes.
http://new.pfaff.com/SiteMedia/PFAFF/Products/Machines/Support-manuals/Creative_1473-manual-EN.pdf

Also see this Youtube video showing how to insert the bobbin after threading.
Pfaff Creative 1473 CD sewing machine in action

otherwise you will have to buy service manual for eBay

PFAFF CREATIVE 1475CD Sewing Machine Service Manual

it's possible that some part of the computer is or has gone out, it would be a good idea to have the machine checked.

where can I download pfaff 7550 menjal

http://sewingonline.co.uk/library/PFAFF-CREATIVE-1475-CD.html