How do you reset a phone?
That was the message I got from a bench technician in Q1 2025. I manage procurement for a 60-person mobile device refurbishing company, which usually means budgets, vendor contracts, and total cost calculations. It did not mean answering Android questions. But that one question was the beginning of a three-month lesson in test equipment procurement.
I will answer the reset directions first, because that is the surface problem. The deeper problem was whether we should rent a Keysight communication test set, buy a Keysight Premium Used instrument, or keep using a surplus communication tester that was causing false failures.
How Do You Reset a Phone? The DuraForce Pro 3 Version
For a Kyocera DuraForce Pro 3 running a standard Android 12 or newer image, the factory reset path is usually:
- Open Settings.
- Tap System.
- Tap Reset options.
- Tap Erase all data (factory reset).
- Confirm the device passcode, if one is set.
If a Google account is on the phone, sign out of it before the reset. If you do not, Android Factory Reset Protection may ask for the previous password on the first boot. That is not a hardware fault, but it looks like one in a high-volume test line. If the phone is enrolled in an MDM system, a factory reset may also not fully clear device-owner status; that is a separate contract step, not a reset step.
Why a Correct Reset Did Not Fix Our Failures
We had just received a batch of about 300 DuraForce Pro 3 units. The process looked simple: reset, run an RF screening test, then send the device to the sales queue. After the first 50 units, almost 15% were failing.
We did the natural thing. We wiped a phone again, waited longer, used a different cable, and still saw the same fail. The technician asked me whether there was a hidden reset method. That was when I started suspecting the equipment, not the phone.
Factory reset clears the previous owner’s network settings and profiles. That sounds good for testing. But a clean phone with no carrier profile has to connect to whatever the test set is emulating. If that emulation does not match the bands and network features the DuraForce Pro 3 supports, the phone will keep searching and eventually time out. Our surplus communication tester was old enough to be cheap, but it did not have the configuration coverage for the LTE and 5G combinations we were testing.
In other words, the reset was working. The test set was not. The phone was being sent to a network that did not exist in the test script.
The Real Cost Was Not the Rental Fee
I started tracking the false failures. Each one took about 22 minutes of bench time by the time a technician logged it, retested it, and asked for a second opinion. At a 15% false-failure rate on a 300-unit batch, that is roughly 990 minutes of labor spent on devices that had nothing wrong with them.
That is the part I want people to understand. When I compared equipment prices, the difference between a Keysight communication test set rental and the surplus unit looked large. The total cost calculation changed once I included false failures, calibration uncertainty, and rework time.
I do not have hard data for other refurb shops. What I can say from our own tracking is that the failure rate dropped below 3% after we changed the test configuration. The phones did not change. The reset procedure did not change. The only thing that changed was the instrument and the script behind it.
What I Almost Did Instead
Before I talked to Keysight, my first instinct was to buy a used communication tester from a surplus broker. The price was low, and the unit came with a calibration certificate from a few years back. It looked like a valid budgeting decision.
The problem was that the calibration did not make it suitable for the devices we needed to validate. The unit had older firmware, limited options, and no clear path for upgrades. A communication test set is not simply a signal generator. It is a small network emulator. If the network you are emulating is not the network your devices need, the measurement is not worth much.
I am not saying surplus equipment is always wrong. I am saying the sticker price is not the total cost.
What Worked: Rental First, Then Keysight Premium Used
The workable plan had two steps. First, we used a Keysight communication test set rental for the pilot phase. That gave us a supported, known configuration while we proved that the process could be stable. It also allowed me to avoid a large capital decision before we understood our own requirements.
Once the pilot showed consistent results, I bought through Keysight Premium Used. It cost more than the surplus unit on the purchase order. It was still less than buying new, and it came with calibration and support structure we could rely on. On a per-device basis, it was dramatically cheaper than paying people to retest devices that had never been broken.
As of January 2025, my spreadsheet for any test equipment purchase has four lines:
- Acquisition cost.
- Calibration and support.
- Expected configuration coverage for the phones we test.
- Cost of failed tests and returns if the equipment is wrong.
Line four is the one that most quotes do not show. It is also the line that convinced me that Keysight equipment could be a better financial decision than a cheaper unit that could not perform the test.
The Bottom Line
So, how do you reset a phone? For a DuraForce Pro 3, the reset is Settings > System > Reset options > Erase all data. Remove any Google account before you start if you want to avoid FRP locks. The entire reset process is easy.
What is harder is the decision after the reset. If your communication test set is not trustworthy, no reset procedure will give you confidence. For our lab, choosing between a Keysight communication test set rental and a Keysight Premium Used purchase was not about avoiding a big invoice. It was about avoiding thousands of dollars of wasted labor caused by a false fail. That is the total cost I now manage.
