Canon NP1550 Service Manual

Also see for NP1550: Service manual

OPERATIONS AND TIMINGB. Outline of Electric CircuitryThe NP-1550's main mechanisms arecontrolled by the microprocessor, PROM,and EEPROM on the DC controller PCB.1. Microprocessor (Q303)• controls the copying sequence• controls the control panel• controls the main motor/scanner motor• controls the scanning lamp• reads the analog signals2. PROM (Q318)• contains the sequence program3. EEPROM (Q315)stores data that can be modified in theservice mode (replaces conventionalvariable resistors and switches)-|*>*!;.....„i.v,.Tn .,.,,..- „,..„„,, ., r .,.,~ .,,^EHPRGM'k a type oT,rtQfvt:,W..w.hfcft". datajrnay;tie Erased or st^ftrfiply/. , ,.''For this reason, the NP-1550's RAMand RAM are not backed up by a lithiumbattery..W^™,,,,^:,,,^.^, ,.,./ ,,, ,„, - .The NP-1550 is equipped with an A/Dconverter and, therefore, its micro-processor can read analog signals.Note:The main motor (M1) is a synchronousmotor that uses the frequency of thepower supply as the reference of itsoperation.The scanner motor (M2) are steppingmotor that use the oscillation frequencyof the crystal oscillator on the DC contrailer.Fluctuations of the frequency in thepower supply during copying operation^affects only the revolution of the mainmotor (M1) and result in :expahsjdn; s Orcontraction of the images. V! ?3-2 COPYRIGHT© 1992 CANON INC. CANON NP-1550 REM JAN.1992 PRINTED IN JAPAN (IMPRIME AU JAPON)