A first-person, immersive day in the life of an appliance repairman

A repairman’s day in first person: an Aige Bluetooth speaker fixed for ¥30; a Tineco floor washer with a charging fault the multimeter can’t pin down, open the pack and find one dead cell, replace all with genuine Samsung cells (IR 9.6–9.8), welded up on the ‘Yao Ni Ming 3000’ spot welder, dock charges at full 28W, charge 49→53 in 5 minutes

Opening: when a tricky job leaves him sweating and stuck, out comes the ‘ultimate weapon’. Job one, an Aige Bluetooth speaker — light won’t come on, won’t charge, something dead inside; after the fix the light is on and it enters Bluetooth mode, ¥30. Job two, a Tineco floor washer with a charging fault, bad contact, ‘Tineco machines are just no good, make do’; the (Fluke) multimeter can’t tell good from bad and can’t find the fault, a sip of tea dregs to calm down. Then the ultimate weapon, the ‘Yao Ni Ming 3000’ (spot welder): control board fine, panel fine, the battery isn’t supplying enough — one cell already dead, replace them all. Genuine Samsung cells, IR tested one by one at 9.6/9.7/9.8/9.8; to tell genuine Samsung, check the QR code on the bottom of the cell (e.g. 981945). Spot-weld the pack, very OK. Back on the charging dock: reads 28W, the machine is 26V 1A i.e. 26W, reaching 27W means it’s charging at full power; 5 minutes on charge, test run fine, charge was 49 and is now 53; smart switching and the ‘return to dock’ prompt work as normal. 439 comments: charges more than fellow creator ‘Jiadian Huatuo’; many ask for a build guide and the principle of the ‘Yao Ni Ming 3000’; Fluke multimeters aren’t cheap; someone lists the repairman’s tools — Fluke multimeter, IR meter, coulomb counter, Li-ion spot welder; which welder is it and how much.

Outcome

Steps7 steps · click a frame to jump

1. 
   1. Opening: the ultimate weapon

   When a tricky fault won’t give, out comes my ultimate weapon; speaker light won’t come on, won’t charge, something dead inside.

   00:00 – 00:10
2. 
   2. Aige Bluetooth speaker fixed, ¥30

   Open and repair the speaker (quite a hassle); light on, enters Bluetooth mode, done; thirty yuan.

   00:10 – 01:26
3. 
   3. Tineco floor washer charging fault, multimeter finds nothing

   Charging fault, bad contact; Tineco machines are just no good, make do; the multimeter can’t tell good from bad and can’t find the fault; a drink to calm down (tea dregs).

   01:26 – 01:43
4. 
   4. Out comes the ‘Yao Ni Ming 3000’; battery under-supplying, one cell dead

   When nothing else works, the ultimate weapon, ‘Yao Ni Ming 3000’; control board fine, panel fine, the battery isn’t supplying enough; one cell is already dead, replace them all.

   01:43 – 02:09
5. 
   5. Genuine Samsung cells: IR 9.6–9.8; check the QR code on the bottom

   Genuine Samsung cells; IR 9.6, 9.7, 9.8, 9.8; to tell genuine ones, check the QR code / batch code on the bottom of the cell (981945 etc.).

   02:09 – 02:42
6. 
   6. Spot-weld the pack, very OK

   New cells spot-welded into a pack and reconnected (on screen), very OK; screen shows codes 2062/2063.

   02:42 – 03:16
7. 
   7. Dock charges at full 28W; 49→53 in 5 minutes

   On the charging dock and charging, reads 28W; the machine is 26V 1A i.e. 26W, hitting 27W means full power; 5 minutes on charge, test run fine, charge 49→53; smart switching and ‘return to dock’ prompt work.

   03:16 – 04:12

Bill of materials

Measured on camera

Creator’s tips

• When the multimeter can’t explain a charging fault, go straight to per-cell IR / voltage in the pack 01:26
• Spotting genuine Samsung: check the QR code on the bottom of the cell 02:30
• Judge full-power charging by whether the dock’s power reading hits spec (26V × 1A ≈ 26W) 03:24

Pitfalls

• Tineco charging contacts make poor contact, the machine is ‘just no good’ 01:12

Li-ion safety

Quotes

Cost & time