Job Cards: Step-by-Step Procedures for the Most Common Repairs

≈ 9 min read · Print / save as PDF

Job Card 1 — Charging-port cleaning (any phone)

1. Power the phone off.
2. Look into the port with a light and magnifier.
3. Gently scrape lint from the back of the port with the pick, moving outward. Do not touch the pins sideways.
4. Brush with a little IPA; let it evaporate completely (2–3 minutes).
5. Plug in a known-good cable: it should click in firmly.
6. QC: charging current on the meter is normal for that phone; the connection does not drop when the cable is wiggled.

Job Card 2 — Phone battery replacement

1. Intake: check battery health and record it. Ask the customer for permission and passcode policy.
2. Discharge to below ~25% if possible.
3. Open the phone (Job Card 3 steps 1–6, or back-first for many Androids).
4. Disconnect the battery connector first.
5. Remove the battery by the model’s method: pull-tabs (slow, low angle), IPA + plastic card, electrical de-bond (Apple manual), or screwed tray.
6. Clean old adhesive from the frame. Fit new adhesive.
7. Place the new battery, press evenly (clamp/roller). Connect it last, after all brackets are in place.
8. Reassemble; replace the frame/screen adhesive if the screen was removed.
9. QC: boots, charges, battery percentage plausible; on iPhones check Settings → Battery → Battery Health and Parts and Service History; run Repair Assistant for genuine parts.
10. Dispose of the old battery safely (taped terminals, fire-safe bin).

Job Card 3 — iPhone screen replacement (screen-first models)

1. Power off. Remove SIM tray. Tape over cracked glass.
2. Remove the two Pentalobe screws beside the port.
3. Heat edges to ≈ 60–80 °C (warm to touch, not hot).
4. Suction handle near the bottom; lift a small gap; insert pick shallow.
5. Slide the pick around, cutting adhesive; avoid the side where display cables run (check manual).
6. Open like a book on the cable side; support the screen.
7. Remove the battery-connector bracket screws. Disconnect the battery first.
8. Remove the display-cable bracket; disconnect display (and on some models, the sensor/front-camera cable).
9. Transfer parts not included with the new screen (earpiece, sensor assembly, brackets) — models differ.
10. Test fit: connect the new screen, then the battery; check touch, brightness, Face ID/True Tone status, proximity. Disconnect battery again.
11. Clean old adhesive; apply new adhesive.
12. Connect screen, connect battery last, refit brackets, close, press, refit Pentalobe screws.
13. QC: full smartphone QC (Appendix B). Check Parts and Service History; run Repair Assistant if a genuine part was used. Tell the customer the screen grade installed.

Job Card 4 — Back-first Android screen or back-glass replacement

1. Power off; remove SIM tray.
2. Heat the back glass thoroughly (adhesive is strong); lift with suction; cut adhesive with picks.
3. Watch for the wireless-charging/NFC coil, fingerprint sensor, and camera lens cover attached to the back.
4. Remove midframe/coil screws and covers; disconnect the battery.
5. Disconnect display and other flexes needed by the model.
6. If replacing the screen: many back-first models require removing the board and battery to free the display; follow the model’s guide. Many replacement screens come pre-fitted to a new frame (“screen with frame”), which saves time.
7. Reassemble, new back adhesive, press and clamp.
8. QC: full QC; for under-display fingerprint sensors, run the manufacturer’s fingerprint calibration procedure if required and re-enrol the fingerprint.

Job Card 5 — Android charging sub-board replacement

1. Confirm the fault: known-good cable and charger, port cleaned (Job Card 1), USB-C meter shows little or no current.
2. Open, disconnect battery.
3. Remove the loudspeaker module/covers over the sub-board.
4. Disconnect the main flex(es) and any antenna cables at the sub-board; remove screws; lift the sub-board (some are lightly glued).
5. Fit the new sub-board; reconnect main flex and antennas (press straight down until it clicks).
6. QC: charging current, fast-charging if supported, microphone (if on the sub-board), signal strength (antenna cables), USB data to a PC.

Job Card 6 — Laptop cleaning and repaste

1. Record temperatures before: idle and 10-minute stress test (HWiNFO + OCCT).
2. Remove bottom cover; disconnect battery.
3. Remove heatsink screws in reverse numbered order; disconnect fan cable; lift heatsink.
4. Clean old paste from CPU/GPU and heatsink with IPA. Measure old pads with calipers or by comparison before discarding.
5. Clean fan and fins with the blower while holding the fan still.
6. Apply paste to the die; fit new pads of the same thickness.
7. Refit heatsink, tightening in the printed numbered order; reconnect fan; reconnect battery.
8. QC: stress test again; temperatures and fan noise should be lower. Record both readings on the job order to show the customer.

Job Card 7 — HDD to SSD upgrade with cloning

1. Check the old drive’s health (CrystalDiskInfo). If it shows reallocated or pending sectors, image it with ddrescue instead of cloning live.
2. Check used space ≤ new SSD capacity. Check BitLocker status (manage-bde -status) and get the recovery key if enabled.
3. Connect the new SSD by USB adapter; clone with reputable cloning software.
4. Install the SSD in the laptop/PC; boot from it.
5. Keep the old drive untouched until the customer confirms all data is present.
6. QC: boots normally, all partitions present, Windows activated, TRIM enabled (fsutil behavior query DisableDeleteNotify returns 0).

Job Card 8 — RAM upgrade

1. Identify the exact RAM type, speed and maximum supported (Lenovo PSREF, Dell/HP manuals, or HWiNFO). Check whether some RAM is soldered.
2. Disconnect battery/AC. Wear the ESD strap.
3. Insert the module at about 30°, press down until the clips lock (SO-DIMM) or press straight in until both latches close (desktop DIMM).
4. First boot may take longer (memory training).
5. QC: capacity correct in BIOS and Windows; run at least one full pass of MemTest86+.

Job Card 9 — Windows clean install

1. Back up the customer’s files (with permission) and confirm what they need (documents, photos, browser bookmarks, licence keys).
2. Check BitLocker; note Microsoft account details the customer must use.
3. Boot from USB; Custom install; delete or select partitions; install.
4. Install chipset, graphics and manufacturer drivers from the device maker’s site; run Windows Update.
5. Restore the customer’s files; install only licensed software.
6. QC: Device Manager shows no unknown devices; Windows activated; Wi-Fi, audio, camera, touchpad working. Delete your shop copy of the customer’s data and record that you did.

Job Card 10 — Laptop screen (panel) replacement

1. Read the exact part number on the old panel label (or from the manufacturer’s parts list) and order an exact match (size, resolution, refresh rate, connector pins, touch).
2. Disconnect the battery.
3. Remove the bezel (clips/adhesive) or separate a glued panel with plastic cards and gentle heat.
4. Unscrew the panel; tilt it forward; peel tape from the eDP connector; pull straight out.
5. Connect the new panel; test before final assembly.
6. Mount, refit tape over the connector, refit bezel.
7. QC: dead pixels, backlight bleed, brightness range, webcam (often in the bezel), lid opening and closing without flicker.

Job Card 11 — Laptop keyboard replacement

1. Identify the design: screwed/clipped (remove from top or bottom), riveted into the top case, or glued.
2. Disconnect the battery.
3. Screwed/clipped: follow the service manual.
4. Riveted: either replace the whole top-case assembly (fastest, more expensive part) or remove the rivets carefully, fit the new keyboard and secure it with small screws (slow; quote the labour honestly).
5. Reconnect the keyboard ribbon (ZIF latch!) and backlight ribbon.
6. QC: every key with a key-test utility, backlight levels, touchpad clicks.

Job Card 12 — Desktop “no power” and PSU replacement

1. Check outlet, cord, PSU switch.
2. Short the PWR_SW header pins briefly to rule out the case button.
3. Measure +5 VSB (purple) on the 24-pin with AC connected.
4. Jumper/PSU-test the PSU out of the system; measure all rails.
5. Try a known-good PSU. If the PC now works, replace the PSU with one of equal or greater wattage and the right connectors (EPS 4+4, PCIe/12V-2x6 for the GPU).
6. If a known-good PSU does not help: minimal configuration outside the case (Chapter 7).
7. QC: 30-minute combined CPU+GPU stress test without shutdown.

Job Card 13 — Phone “dead, no power” first diagnosis (board level)

1. Try a known-good charger and cable for 15 minutes; try a force restart.
2. Open, disconnect the battery; measure battery voltage. A battery under about 3.0 V may be deeply discharged or faulty — try a known-good battery.
3. Connect the boot cable; set 4.0–4.2 V, limit 1 A.
4. Read current before pressing power: above a few mA = leakage/short on VBAT.
5. Press power: compare the pattern to Figure 16.2.
6. Short → inject and locate (Chapter 16). No reaction → check power-button line and VBAT path. Stuck current → check main PMIC rails against known-good.
7. Quote the customer after diagnosis, with a clear success estimate and data note.