How We Stress Test PCs Before They Leave the Workshop
Fixing the obvious fault is only half the job. A machine that boots cleanly on the bench can still fail under load an hour after the customer gets it home — because heat, memory errors, and storage problems often only show up when the hardware is working hard.
That's why every machine we repair or upgrade at GLS Tech goes through a structured stress test before it leaves the workshop. Here's exactly what we do and why each stage matters.
Why Stress Testing Matters
Most faults don't fail 100% of the time. A marginal RAM stick might work fine at idle but corrupt data under load. A dying hard drive might boot Windows perfectly yet fail the moment it has to read a large file. A poor thermal paste application after a repair will only show up when the processor is running flat out for several minutes.
Returning a machine to a customer without stress testing it is guesswork. We prefer certainty.
Stage 1 — Memory Testing
Before Windows even boots, we run MemTest86 — a dedicated memory tester that boots from a USB drive and hammers the RAM with a series of read/write patterns designed to expose faults that normal use would never trigger. A single pass covers the basics; for machines that have had memory replaced or where we suspect intermittent errors, we run multiple passes overnight.
Faulty RAM is surprisingly common and is responsible for a huge proportion of unexplained crashes and blue screens. If MemTest86 reports errors, the RAM is replaced before anything else happens.
Stage 2 — Storage Health Check
We pull a full S.M.A.R.T. report from every drive in the machine. S.M.A.R.T. is a monitoring system built into hard drives and SSDs that tracks indicators like reallocated sectors, uncorrectable errors, spin-up failures, and overall drive health. A drive with a clean S.M.A.R.T. report isn't guaranteed to be fine, but a drive with bad S.M.A.R.T. data is definitely on its way out.
For mechanical hard drives, we also run a surface scan to check for bad sectors across the full disk — not just the areas Windows happens to use. This is the test that catches early drive failures before they become data loss events.
If a drive has bad sectors or failing S.M.A.R.T. attributes, we flag it immediately. We won't return a machine with a drive we know is failing — we'll tell you what we found and what your options are before we hand it back.
Stage 3 — CPU and System Stability
With the storage and memory confirmed healthy, we load the operating system and put the processor under sustained load using a CPU stress tool. This runs the processor at or near 100% utilisation for an extended period — typically 30 to 60 minutes depending on the repair type — while we monitor temperatures throughout.
This catches two things: thermal throttling (where the processor slows itself down because it's getting too hot) and system instability under load (crashes or freezes that would only appear when the machine is working hard). A machine that crashes during CPU stress is not a machine that goes back to a customer.
Stage 4 — Thermal Monitoring
Temperature monitoring runs throughout the stress test. We watch CPU, GPU (where applicable), and drive temperatures in real time. On a well-maintained desktop, a modern processor should remain comfortably below 80°C under full load. Laptops run warmer by design, but we have reference points for normal operating ranges.
If temperatures are running high — even if the machine isn't crashing — it means the cooling system needs attention. Common causes include dried-out thermal paste, blocked heatsink fins, or a failing fan. We address these before the machine leaves, not after the customer reports it running hot next week.
Stage 5 — Post-Repair Functional Check
Finally, we verify that everything specific to the repair is working correctly. If we replaced a screen, we check it at multiple brightness levels and angles. If we replaced RAM, we confirm the system sees the correct amount. If we did a Windows reinstall, we check Windows Update, drivers, and the activation status. Nothing gets signed off on assumption.
What This Means for You
When you collect a machine from GLS Tech, it has been tested — not just switched on and handed back. The stress testing process adds time to some jobs, and we think that's completely worth it. A machine that passes our tests is a machine we're confident will perform reliably at home. We apply the same standard to gaming PC repairs as we do to everyday machines.
Not all repair shops do this. It's worth asking. If a shop can't tell you how they test a machine before returning it, they probably aren't testing it at all — and you're taking the risk that the fix holds up under real-world conditions.
Need Your PC Repaired Properly?
We cover Consett, Stanley, Blackhill, and across County Durham. No fix, no fee — and every repair is stress tested before you get it back.