About 5 years old. Why does it often have a blank screen?

Could be battery failure

water will have an affect on it if it has not been dried out properly the screen controller chip that is on the logic board will get damaged, =, they are not waterproof, you will need another logic board to repair this fault., can also damage the battery and the screen being in water for any amount of time.

If the rechargeable battery is more than 3 - 4 years old then the battery could be worn out. Rechargeable batteries have a finite number of charge and discharge cycles and will lose their charge capacity over time, i.e. won't charge to 100% and gradually the charge reduces until the battery won't charge up at all. OR The battery shows a 100% charge but when the adapter is disconnected the battery drops off to zero capacity in a very short time. If the battery drops to an unacceptable charge level then the battery needs to be replaced. Rechargeable batteries will fail if stored in a discharged state for long periods.

try a new battery

From your description the solar cell charges the battery and keeps it topped up. I think the rechargeable battery is the problem because when the screen goes blank the battery level drops to low and the LCD blanks out which would explain the intermittent operation of the watch. I think it is worth getting it checked out with an estimate.

Usually a stuck lens is caused by dirt getting into the gap between the lens barrel sections. The simplest thing to try is a freshly recharged battery, which might just have the power to overcome the resistance. Plugging in an AV cable sometimes blanks the screen, leaving just a bit more battery power for the lens.

Try taking battery out with phone on. Leave Battery out for at least a minute and put back in. If still white and phone is under a year old, contact service provider. They usually have a one year warranty if phone is under a year with no physical damage. If phone is a refurbished phone you may only have 60 to 90 days of warranty.

Your battery cell is too weak to perform it's work, it has reach it's limits of working.

It's due for change,get a new battery and charge for about 5 to6 hours before use.

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