Ask before you touch
The customer knows things the phone can’t tell you. Ask, and write the answers on the ticket:
- What exactly is wrong? “It won’t charge” can mean no charging at all, slow charging, or only charging at an angle.
- When did it start, and what happened right before? A drop, liquid, an update, a new charger, a previous repair.
- Has anyone opened it before? Previous repairs change what you’ll find inside.
- What still works? Calls, sound, cameras, Face ID or fingerprint, buttons.
Your device intake checklist covers these questions and the condition notes, so you aren’t relying on memory.
Protect the data first
Some tests and some repairs can end with a phone that needs to be restored. Before you go further, ask whether the customer has a recent backup, and if not, whether they can make one now. Apple and Google both publish step-by-step backup instructions you can point customers to: back up an iPhone with iCloud and back up an Android device.
If the phone can’t be backed up because it doesn’t turn on, say so on the ticket and tell the customer that data can’t be guaranteed. Never promise data you can’t protect.
Look before you test
A careful visual check catches a lot before any tool comes out:
- Frame and screen: bends, cracks, lifted edges. A lifted screen can be a sign of a swollen battery. If the battery looks swollen, stop and handle it as a safety issue before anything else.
- Ports: lint, debris or corrosion in the charging port, which you can check under magnification.
- Liquid signs: corrosion, residue, or liquid indicators where the model has them.
- Signs of previous repairs: missing screws, non-original parts, broken adhesive.
Test everything, in the same order
Test every function the phone can still perform, in a fixed order, and mark each one OK, Fail or Not tested: power, display, touch across the whole screen, front and rear cameras, earpiece, speaker, microphone, charging, buttons, Wi-Fi, cellular, biometrics. A fixed order means nothing gets skipped when the counter is busy.
This step also protects you. If the rear camera didn’t work before the screen repair, the ticket shows it.
Narrow it down by symptom
Start with the simplest, cheapest explanation and work toward the expensive ones:
| Symptom | Check first | Then |
|---|---|---|
| Won’t turn on | Known-good charger and cable; let it charge, then try a forced restart | USB power meter reading, battery, then board |
| Won’t charge | Debris in the port, a different known-good cable | Charging port, battery, then board |
| Vibrates or rings but no picture | A known-good screen connected temporarily | Display connector and board |
| Touch not working in places | A known-good screen | Connector, then board |
| No sound on calls | Earpiece mesh, settings, a call on speaker | Earpiece, microphone, then board |
Prove it with known-good parts before you order
Before you order a part or quote a repair, connect a known-good test part and see whether the problem goes away. If a test screen fixes the display, you can quote a screen with confidence. If it doesn’t, you just saved the customer from paying for a part that wouldn’t have helped. Label test parts clearly so they never end up in a customer’s phone.
The test gear for this step is on the phone repair tools list. Working on a laptop or desktop? Use the computer repair checklist.
Write it down, then quote
Write the findings on the repair ticket: what you tested, what failed, what fixed it with a test part. Then quote from your price worksheet, get the customer’s approval, and record it before any repair begins.
Decide in advance whether you charge for diagnosis, how much, and whether it’s credited toward the repair. Tell the customer before you start, not after.
Know when to stop
Some problems go beyond a standard bench diagnosis: board-level faults, serious liquid damage and data recovery. Tell the customer what you found, what the options are, and what you can and can’t promise. A clear “this needs board-level work” is better than a repair that fails next week and comes back under your warranty.
Where RepairAmigo fits
RepairAmigo is free software for cell phone, computer and electronics repair shops, built inside a busy repair shop that has processed more than 50,000 tickets. Problem lists by device type keep intake consistent, every ticket can hold the serial number or IMEI, comments and the assigned tech, and custom statuses show where each job stands, such as waiting for the customer’s approval. If the shop turns on optional texting, the customer can get a text when the device needs their input. It runs on a computer in your shop with no ticket or user limits. See cell phone repair shop software or read what “free” means here.
Frequently asked questions
How do repair shops diagnose a phone?
They ask the customer what happened, check that the data is backed up, inspect the phone visually, test every function in a fixed order, narrow the problem down by symptom and confirm it with a known-good part before quoting a repair.
How do you diagnose a phone that won’t turn on?
Start with a known-good charger and cable, let it charge, and try a forced restart. Then check what it draws with a USB power meter, and test the battery before suspecting the board. Tell the customer that data can’t be guaranteed.
How do you know if it’s the charging port or the battery?
Clean the port and try a known-good cable first. If the phone still won’t charge, a USB power meter and a known-good charging port or battery connected temporarily show which part is at fault.
Should a repair shop charge for diagnosis?
That’s a business decision. One option is to charge for diagnosis and credit it toward the repair if the customer goes ahead. Whatever you decide, tell the customer before you start and write it on the ticket.
Is RepairAmigo free?
Yes. RepairAmigo is free software for cell phone, computer and electronics repair shops, with no ticket or user limits. Each ticket keeps the problem, the test notes, the assigned tech and the status in one place.
Questions?
Read the setup guide, email support@repairamigo.com, or go back to More about RepairAmigo.
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