Sharp DV-550U, Service Manual

Page: 26 / 84

DV-550U
11-4
No
No
No
No
Laser is not turned off.
Yes
Is "H" measured at IC303 (pin 51)?
Replace IC303 or IC707.
Yes
Is 3.3V measured at the emitter of Q301. Check 3.3V line.
Is 3.3V measured at the collector of Q303.
Is "L" level measured at the collectors of Q303 and Q304?
Yes
Is 3.3V measured at the AB connector (pin 11)? Check between Q303 and AB connector.
Yes
Check AB connector, and replace pickup.
No
No
No
Neither image nor voice is output.
Insert disk.
Yes
Is disk clamped? Check loading SW.
Yes
Is RF signal measured at IC303 (pin 34)?
Clean objective lens.
Is it corrected when main board is replaced? Replace pickup.
Yes
Check IC6001, IC6002 and IC6003.
Does pickup move up
and down? Is FE signal output
from IC707 (pin 38)? Check the line between IC303
(pin 27) and IC707 (pin 38).
No No
No
No
No
No
Is FE signal measured
from IC303 (pin 27)? Is FE signal output
from IC707 (pin 43)? Check the line between IC303
(pin 27) and IC707 (pin 38).
Is signal measured
from IC303 (pins 57,
58, 59 and 60)? Is FE signal output
from IC707 (pin 43)? Replace IC707.
Is any signal measured
from IC301 (pins 17 and
18)? Is focus drive signal
measured from IC702
(pins 17 and 18)?
Is 8V measured at IC702
(pin 21)?
Check 8V line.
Replace pickup.
Focus is not pointed.
Is drive signal measured
at the connector AB (pins
2 and 4)? Replace IC702.
Check connector unit or
replace pickup. Check between IC702 (pins
17 and 18) and connector AB.
Yes Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No