Hi @yaso39064
A 1 beep error code is a motherboard or BIOS Rom failure
Try a full power refresh in case it is a corrupted BIOS and check if that resolves the problem.
Here’s the procedure:
a). Disconnect the charger from the laptop if connected.
b). Disconnect the main battery from the motherboard.
c). Remove the RTC coin cell battery from the motherboard.
Here’s the [link|https://dl.dell.com/topicspdf/inspiron-15-5570-laptop_service-manual_en-us.pdf|service manual] applicable to the laptop. Go to p.21 and p.30 to view the procedure to remove the battery and the RTC coin cell battery respectively.
When the RTC battery is removed measure its voltage. If it is <2.6V DC replace it. It looks like it is a CR2032 coin cell Lithium battery which is commonly available everywhere e.g. supermarkets
d.) Reinsert the RTC battery (or its replacement). (+ve on top as marked on the battery)
e). Reverse the above steps to re-assemble the laptop.
f.) When the laptop is completely re-assembled, connect the charger and try to turn on the laptop.
If it starts OK there may be a message about the date and time being incorrect. This is normal as the BIOS has been completely reset back to its default settings. Once the date and time have been adjusted the message won’t appear the next time that the laptop is started.
If you had previously changed any user defined settings in BIOS to suit whatever specific hardware configuration that you had for the laptop, then these will have to be set again.