iMac crashes during sleeep

I have a 7 year old iMac with the following specifications:

Retina 4K, 21.5 inch Display, 2017

Processor 3.6 GHz Quad-Core Intel Core i7

Graphics Radeon Pro 560 4 GB

Memory 32 GB 2400 MHz DDR4

It has a 500 GB SSD Internal HDD

I have installed macOS Ventura 13.6.6

In the past few days I have had difficulty with my iMac not waking up from Sleep Mode, this happens infrequently and the longer the iMac has been sleeping the more likely that this will occur.

I have also had trouble starting the iMac with the Power Button, it can take several attempts to finally get it booted up and running.

When the iMac is in usage there are no noticeable problems.

I have tried using the following remedial measures:

Reset VRAM

Reset SMC/PMU

Unplugged ALL devices attached/connected to the iMac and unplugged the iMac from the power supply for 10 to 15 minutes before restarting with NOTHING connected to it at all.

I have run the Apple Diagnostics Tool, which did not find any hardware issues or other technical problems.

I have made a bootable installer USB Drive using macOS Ventura 13.6.6 and used this to completely erase my iMac and perform a fresh clean install of the operating system.

I left the iMac in its unmodified "virginal" state with no apps installed(only default macOS apps) and made absolutely ZERO changes to its configuration.

Yet despite doing all this my problems persist.

I fully know my iMac is getting long in the tooth at approximately 7 years of age.

If a repair or replacement of a component can be done at a reasonable cost, I would strongly consider that option as I would like to keep it alive for a while longer. My financial situation means I need more to time to save enough funds for a replacement.

I do hope this aging desktop iMac can be saved.