I bought this camera for 150 swedish kronor at a flea market in Helsingborg last summer. It even had working batteries included for the price. Thats a problem with this camera, it uses PX640 mercury batteries that are banned nowadays.
It works ok but you have to be careful to make sure that the automatic exposure system is activated when you press down the shutter. It seems like it needs a little cleaning of some electrical components…
Some technical information from this manual at The Yashica-guy website:
Lens Color-Yashinon DX F1.7 40mm lens composed of 6 elements in 4 groups; minimum focus 2.6 ft [0.8 meters]. Angle of view 56 degrees.
Shutter Electronic shutter with continuously variable speeds from LT [Long Time to 30 secs] to 1/500 sec.; features high performance IC and three semi-conductors; built-in-self-timer with self-locking system.
Exposure Control Fully automatic electronic exposure control sets the precise shutter speed through preselection of the lens aperture; “Top- Eye” SBC sensor; aperture scale from F1.7 to F16 [three Exposure Symbols for easy aperture preselection]; ASA range from 25 to 800; Electro Flash Symbol; EV range from EV 0 to to EV 17; Red and Yellow Exposure Indicator Arrows visible in the finder and on camera top.
Viewfinder Incorporates bright frame which moves diagonally with focusing operation to compensate for parallax automatically; magnification ratio 0.26X at infinity.
Focusing Image superimposition type rangefinder incorporated at the center of the finder field; distance scale from 2.6ft to infinity [0.8m to infinity]; depth-of-field scale on lens barrel.
Film Advance Single action film advance lever registers count of exposure on auto-resetting exposure counter and sets the electronic shutter to ‘standby’ simultaneously with film wind; multi-slot take-up spool for easy film loading; exposure counter counts back during film rewind; crank-handle film rewind.
Auto Flash System Yashica Electro Auto Flash System using exclusive ES-20 Auto strobe unit; FPS (Flash Pulse Selector) automatically sets shutter to flash synchronization speed; X contact; Electro Flash Symbol plus dot index [M synch] for flashbulb (AG-3N); auto flash feasible with AG-3N or AG-38 flashbulb.
Other Features Accessory shoe [incorporated direct X contact and light cut-off signal terminal]; X synchro terminal; shutter lock; battery check lamp doubles as exposure counter illuminator; accepts 52mm screw-in type filters and 54mm slip-on type lens shade.
SIZE & WEIGHT 123 X 75.7 X 64mm; 580 grams
A few pictures of it:



The small arrows in the middle of this last image will light up and tell in what direction to turn the aperture ring to avoid incorrect exposure. They are also visible in the wievfinder.

Some pictures taken with it:

