Most 1Chess Clock problems are setup problems rather than timing problems. Start by identifying what changed: no sound, a clock that is paused, or a game that has returned to its starting time. Check the setting or control that matches the symptom before changing the time control. The getting-started guide covers the normal hand-over between the two player panels.
Start with the symptom
Keep the current game still while you investigate. If one player is active, use the central pause control before opening settings. The app also pauses an active clock when it becomes inactive, so returning from another screen is a good moment to check the visible state instead of assuming that time kept running. Do not keep tapping both player panels while testing; a panel tap is part of the turn hand-over.
If the sound is missing
Open the sound settings and confirm that sound alerts are enabled. 1Chess Clock also exposes haptic feedback and a low-time warning, so decide which signals both players actually want before the game. Then make a short test: start the clock, switch turns once, and let the active side approach the warning threshold only if you need to check that alert. A phone can also be muted or connected to another audio device, so check the device itself before treating the app as faulty. If the game is already under way, avoid changing several settings at once; pause first and agree on the change.
If pause behaves unexpectedly
The pause action holds the current game so the players can resume it with the same remaining time. It is different from tapping a player panel, which changes whose clock is active. Use the pause and reset guide for the exact distinction. If the clock paused because the app went inactive, return to the game and confirm which side was active before resuming. Do not use reset as a substitute for a short interruption.
If the clock was reset or tapped by mistake
Stop and tell both players what happened. Once the starting display is back, treat the position as a new clock setup rather than trying to reconstruct the old time from memory. Recheck the starting time, delay mode, and player panels. For a club session or event, follow the organiser's procedure for an accidental tap or reset; the app cannot decide that dispute for you. The long-game setup checklist includes a useful pre-game test routine.
Check the setup before restarting
Place the phone where both players can reach their own side, confirm the mode together, and make one practice hand-over. If the clock is being used in a club or tournament context, read the phone-versus-tournament-clock guidance before relying on it. Only start again when both players agree that the displayed time and the handling of interruptions are clear.