The JVC KD-G421 is a car stereo that can play MP3 discs and is set up to connect to an iPod and your car CD changer. You can store up to 24 radio stations in the unit's memory and even connect the stereo to your phone via Bluetooth. The layout of the G421 should be familiar to anyone who's used a car stereo before, and it shouldn't be difficult to get to grips with the basics.
Press the "Power" button. This is located in the top left hand corner of the G421, on the left hand side of the disc slot.
Press the "Source" ("SRC") button repeatedly to cycle through your available audio sources. This button is located in the bottom left hand corner of the unit's front display, directly underneath the down arrow on the left hand side. Stop pressing "Source" when you see the radio bandwith show up on screen. This will be "FM1" unless you've fiddled around with the unit previously.
Choose which bandwidth you want to listen to by pressing the "Band" button until your selection is displayed in the bottom left of the display screen. The "Band" button is located to the right of the "Source" button.
Press the "Skip/Tune" buttons to search for a station. These buttons are on the far left of the G421, mounted on the same control as the "Up" and "Down" arrows. The "Skip/Tune" buttons occupy the horizontal axis. Press either one to search for stations. Pressing the right "Skip/Tune" button will search at higher frequencies, and pressing the left one will search lower frequencies.
Press and hold "Skip/Tune" to tune the radio manually. An "M" shows up on the right of the display when the manual set mode is activated. Release the button, and then find your desired station by pressing the "Skip/Tune" buttons to adjust the frequency as needed.
To store a station into the G421's memory, press and hold any of the six number buttons underneath the display screen. This will store the station in that space. There are six spaces for each band, so you can store 18FM stations and six AM stations in total. A "P" will flash on-screen, followed by the number you pressed. When the flashing ends, the station has been stored.
Adjust the volume by turning the "Control Dial." This large, circular button is located to the left of the display screen. Turn it clockwise to increase and counter-clockwise to decrease the volume.
Press the "Source" button until "Disc" is displayed on the display screen, or alternatively, insert a disc into the CD slot. This will play the disc.
Scroll through to "CD-CH" with the "Source" button if you're playing a disc from your CD changer. Then choose which disc you want to play by pressing the relevant number button.
Skip forward or backward to a track by pressing the "Skip/Tune" buttons. You can also jump directly to a track by pressing the number buttons. By pressing and holding any one of the buttons, you can select tracks 7-12.