Slow performance is usually storage or RAM — not the whole computer
When a machine crawls, people assume it's worn out. Almost always, it's the hard drive or a shortage of memory. Both are replaceable parts, and either upgrade costs far less than a new computer while delivering most of the same feeling of speed.
Won't turn on? Power supply or battery — both replaceable
A computer that's completely dead looks like a total loss, but the most common causes are the cheapest parts: the power supply in a desktop, the battery or charging port in a laptop. The data on your drive is usually completely untouched.
Overheating is a $50 fix, not an $800 replacement
Computers that run hot and shut themselves down usually need their fans cleaned and fresh thermal paste — routine maintenance, not a death sentence. Doing it early also prevents the heat damage that genuinely does kill machines.
Replace when the repair exceeds ~60% of a comparable new machine
That's the honest threshold. If your laptop is worth $500 and the fix costs $350, put that money toward a replacement — and I'll tell you so. Below that line, repair wins: less cost, less waste, and no weekend lost to setting up a new machine.
Always get a diagnostic first
You can't make a good repair-or-replace decision without knowing what's actually wrong. A proper diagnostic turns a guess into a number — and once you have the number, the decision usually makes itself.
Bring me the machine and I'll tell you straight: fix it, or put the money toward something new.