Wednesday, April 29, 2026

DIY Series 105: Dibea GT200 Robotic Vacuum Cleaner Malfunction

Dibea GT200 Robotic Vacuum Cleaner Malfunction

Based on the behavior of the Dibea GT200 (and similar Dibea/Airbot models), the 2-beep, 5-second shutdown is a safety mechanism indicating a motor protection shutdown caused by an obstruction or blockage. The vacuum detects that the motor is working harder than usual due to restricted airflow or a jammed roller, so it shuts down to prevent damage. 

This behavior typically indicates the blocking and turning protection function has been triggered to prevent motor damage. 

Common Fixes for 2-Beep Error:

  • Clear Brush Obstructions: Check the main floor brush and side brushes for tangled hair, strings, or debris that might be jamming the rotation. Manually rotate them to ensure they spin freely.
  • Check the Bumper: Debris might be stuck behind the front bumper, making it think it has collided with an object. Tap or shake the bumper gently to dislodge any trapped particles.
  • Clean the Sensors: Use a dry, soft cloth to wipe the sensors (cliff sensors and collision sensors) located on the front and bottom of the unit.
  • Empty the Dustbin: A full dustbin or clogged filters (HEPA) can cause the motor to overwork and shut down.
  • Verify Battery Level: Ensure the unit is fully charged, as a dying battery can cause sudden stops immediately after starting. 

If the issue persists after these steps, the side brush motor or main motor may be faulty and require professional repair.

Findings:

  • After charging for a long period of time, Dibea GT200 is still having the 2-beep, 5-second shutdown.
  • Open up the battery compartment, check the battery pack using multimeter.
  • Battery pack malfunction, replaced with new battery pack.
Tools Required:
Cost Involved:

Other Related Study (For Future Reference)

  • Motor Specs Understanding

Example: Side Brush Motor (RF-500TB-14350)

Mabuchi RF-500TB-14350 6-12V with Gear

  • The RF-500TB-14350 motor features a cylindrical body with a nominal diameter of 32 mm (approx. 1.26 inches) and an approximate height of 19.6 mm. It is a carbon brush, permanent magnet DC motor commonly used in home appliances, characterized by a 2 mm shaft diameter and a 9000 RPM speed range at 6V-12V. 

  • RF = Round Type, Precious Metal Brushes

  • 500 = Armature Diameter (32mm) + Housing Length + Armature Pole
  • TB = Ring Shape Isotropic Magnet + Motor Height (19.6mm)
  • 14350 = Magnet Wire Diameter (0.14mm) + Winding Turns (350) = <12V, 9000RPM

  • Universal Pinion Extractor / Motor Gear Puller


A Universal Pinion Extractor or Motor Gear Puller is a precision tool specifically designed to remove press-fit gears from small motor shafts, such as the 2mm shaft on your RF-500TB series motor. Using a puller prevents damage to the internal motor bearings and ensures the shaft remains straight.

Operating Steps
    • Selection: Choose a thimble/pin based on the motor shaft diameter.
    • Setup: Install the rotating rod and tighten the pin into place.
    • Alignment: Snap the motor into the puller's plate and align the shaft with the pin.
    • Extraction: Turn the handle clockwise; the pin will press the shaft while the plate holds the gear, pulling it off.
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Thursday, April 23, 2026

DIY Series 104: Alpha SMART 18i Water Heater (Heater Not Working)

Alpha SMART 18i Water Heater (Heater Not Working)


Symptoms:
  • When you power on the Alpha Smart 18i, it automatically runs a 10-second self-diagnostic "Auto Test". If the LEDs blink and then stop without allowing the heater or pump to start, it typically indicates that the unit has detected a safety fault or an internal hardware failure.
  • The blinking lights are GREEN. (If they are RED, the unit is intentionally staying off for safety.)
  • Try pressing the TEST button and then the RESET button to check the safety protection. Upon press TEST button, the GREEN LEDs turns into RED. It actually means the built-in Earth Leakage Sensing Device (ELSD) is performing its safety function correctly. RESET button will bring it back to normal mode.

Findings:
  • If it stops heating but the pump still runs, you should check the thermal cut-out button on top of the tank. For this case, both heater and pump are not working, thus most likely it is the board that is malfunction.
  • A burnt mark on the LVDC2 (Low Voltage DC) Board confirms a hardware failure. This specific board is responsible for converting power to run the DC pump, the control logic, and the safety sensors. Once it has a burnt mark, the circuit is broken, which is why the heater and pump won't respond to the knobs.
  • Found both primary filter capacitors (10uF/400V) and fuse (T2A) were burnt. Those specific capacitors are the "heart" of the power filter; once they dry out or bulge, they cause the voltage ripples that blow the fuse.
  • This LVDC2 Board is a modular part. You can replace the LVDC2 board (~US$40) specifically without replacing the entire heater (US$100 ~ US$150), or further debug on which parts are malfunction and replace the broken parts.

Videos:
  • [Before] Upon power on, after "Auto Test" completed, heater is not working (Heater LED is OFF) even the Temperature Control knob is turned.
  • [Before] TEST & RESET is functioning accordingly

  • [After] Upon power on, tested the LVDC2 Board is working. LVDC2 Board RED LED is ON.
  • [After] Upon power on, tested both Temperature Control knob and Pump Control knob are working.
  • [After] Installation completed, water heater is working fine.


Photos:
  • Turn off the power supply, open up the front cover
  • Disconnect the 3 wires (L/N/E) and unscrew 3 screws to take down the water heater
  • Suspect the LVDC2 Board malfunction, on board LED is not turn on when power on
  • Found the burnt mark near primary filter capacitors (10uF/400V) 
  • Both capacitors (10uF/400V) and fuse (T2A) were broken
  • Order replacement parts and replaced 3 components (10uF/400V capacitors & T2A fuse)






Tools Required:

Cost Involved:

Notes:

To catch a potential failure before the board burns out again, watch for these three early warning signs that the capacitors are weakening:
  • The "Blinking Delay" at Startup 
    • When you first switch on the wall heater switch, the Auto Test LED should blink and stabilize quickly (usually within 10 seconds).
    • The Warning: If the LEDs take longer than usual to stop blinking, or if they flicker weakly before turning solid, the capacitors are likely struggling to hold a steady voltage.
  • Pump "Stuttering" or Weak Start
    • Since those capacitors help provide the DC power for the inverter pump:
    • The Warning: If you hear the pump "struggle" to start, or if the water pressure fluctuates slightly even when your house water pressure is steady, the DC rail is becoming "noisy" or unstable.
  • The "Ghost" Trip
    • The Warning: If the unit occasionally trips its own internal ELSD (the light turns RED) for no apparent reason, but works fine after you press RESET, the capacitors are likely failing to filter out electrical "noise," causing the sensitive safety microchip to trigger a false alarm.
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Sunday, April 19, 2026

DIY Series 103: Samsung WA88V4 Washing Machine Repair (Power Trip)

Samsung WA88V4 Washing Machine Repair (Power Trip)

Symptoms:

  • Samsung washing machine causing power trip when power on.
  • After replaced new motor, the motor starts spinning immediately after power it on.
  • The motor is getting heat up immediately after power on, which is abnormal.
  • There is definitely shorted somewhere, and the leakage current go thru the motor continuously and heat up the motor.
Findings:
  • Found out that the washing machine was placed under an aircond outdoor unit, where water dripped directly onto the washing machine's control panel (near the place where Triac located), so somewhere on the main control board was shorted.
  • After study online, looks like most likely caused by shorted motor Triac on the main control board.
  • Since the original Triac T835H-8F (JieJie Microelectronics) is difficult to get locally, I opted to buy compatible Triac BTA16-800BW (STMicroelectronics). Keyword is "Snubberless" Triac.

Part 1: Changing Motor & Capacitor

Part 2: Debug Main Control Board & Changing Triac
Photos:
  1. Open up the Control Panel to take out the Main Control Board
  2. Remove the Main Control Board from Washing Machine
  3. Cut the PCB housing where Triac is located
  4. Identify the malfunction Triac (T835H) using multimeter
  5. Remove both Triac (T835H) from the PCB (better use same Triac on board)
  6. Solder new Triac (BTA16-800BW) onto the PCB (top view)
  7. Solder new Triac (BTA16-800BW) onto the PCB (bottom view)







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Wednesday, April 15, 2026

Info: Journey into Local U

Journey into Local U



The journey into a local university in Malaysia is a multifaceted process that transitions from post-secondary preparation to active campus life. Most students follow a structured pathway starting from their SPM (Sijil Pelajaran Malaysia) results to gain entry into public (IPTA) or private (IPTS) institutions. 

Choosing Your Entry Pathway

  • Your pre-university choice determines your speed of entry and the competitiveness of the degree programs you can access.
  • Matriculation (Matrikulasi): A fast-track (usually 1-year) and cost-effective route primarily for public universities.
  • STPM (Form 6): A rigorous national qualification (1.5 to 2 years) equivalent to A-Levels, widely recognized for entry into top public universities like Universiti Malaya (UM).
  • Foundation/Diploma: Specific to individual universities, offering a direct bridge to their respective degree programs.
  • A-Levels / IGCSE: International qualifications that are also accepted by local universities as equivalent to STPM. 

The Application Process

  • Securing a place involves navigating centralized or direct admission portals. 
  • UPU Portal: The main gateway for public university applications. It uses a merit-based system, often resulting in high competition for popular courses like Medicine or Law.
  • Direct Intake (Saluran Terus): An "alternative route" where students apply directly to public universities, often bypassing the standard UPU merit competition, though fees may differ.
  • Private Enrolment: Platforms like Uni Enrol or Uni Assist help students match their grades with over 250 private institutions and secure scholarships.

*************************************************

(1) SPM (Sijil Pelajaran Malaysia)

  • SPM 2024 Result Annoucement:
    • Date: 24/Apr/2025 (Thu)
    • Time: 10:00am
    • How to Check:
      • School: Candidates can collect the result slip in person at respective school
      • Online: myresultspm.moe.gov.my (only available for a period of time)
      • SMS: Type <SPM NoIC AngkaGiliran> and send to 15888
    • Total Candidates: 402,956 candidates

(2.1) Application via UPU: Diploma / Foundation for SPM Leaver
  • UPUONLINE application open for SPM / STPM / Equivalent
    • Phase 1: 10 Feb – 14 Mar 2025
    • Phase 2: 14 Apr – 15 May 2025
  • UPU Application Procedures
  • Successful: Offer from UniMAP (via UPU)
    • Acceptance: Accepted offer and payment done on 18/Jun/2025
    • Reject & Refund
      • Submitted reject offer on 01/Jul/2025 due to received offer from Matriculation
      • Received refund from UniMAP on 07/Jul/2025


    (2.2) Application via MoE: Matriculation College (Kolej Matrikulasi)

    • SPM 2024/25 candidates can apply online starting from:
      • Phase 1: 1 December 2024 – 28 February 2025
      • Phase 2: 24 April 2025 – 28 April 2025
    • Kolej Matrikulasi Kejuruteraan Kedah (KMKK): 2nd Intake
      • Physical Reporting: 2025-07-06 (Sun) @ 08:30 - 13:00
      • Location: KMKK
      • Total Students Reported (2nd Intake): 135 pax
    • BSHP (Bantuan Sara Hidup Pelajar) - Student Living Allowance
      • Application open to all matriculation students (by default)
      • Online checking is possible from 16/Jul/2025 @ 10:00 onwards
      • Application was rejected. Normally allowance (RM250/mth) will be given to those students with family household income below RM10k only (mainly for B40 and M40 family)
    • Matriculation's Semester Result Checking

      • Candidates for PSPM, SDS Semester I, SES Semester I and SES Semester III, Session 2025/2026 can check their examination results starting January 6, 2026 (Tuesday) at 10.00 am via the following methods:
      • B. PHONE
        1. Respective colleges.
        2. Matriculation Division of the Ministry of Education (MoE)
          (via 03-8884 4083 or 03-8884 4020)
    • MUET (Malaysian University English Test)
      • MUET requirements are primarily determined by the specific Malaysian university and program you're applying for, generally needing a minimum Band 3 or higher, with competitive fields like Medicine or Law often requiring Band 4 or even Band 5. To take it, you must be a pre-university, STPM, diploma, or matriculation student planning to enter a local degree program, registering online via the official MPM portal or your institution. 
    • PPC (Penghantaran Pelajar Cemerlang)
      • PPC Application (2026)
      • Offer for PPC Interview (2026)
      • Pending offer from PPC (if any): <Est. Jul/2026>

    (3) Application via UPU: Degree for STPM / Equivalent
    • UPUONLINE application open for SPM / STPM / Equivalent
      • Phase 1: 29 Jan – 23 Mar 2026
      • Phase 2: 13 Apr – 15 May 2026
    • UPU Application Procedures
    • Note: For certain selected universities/courses @ UPU application, an interview is required (either attend physically / via online).
    • Interview Annoucement: 
      • Date: From 10/Apr/2026 onwards (depends on each university)
    • Interview Appointment: 
      • UPM: 18/May/2026 - 21/May/2026 (waiting for interview time slot)
      • UPM: Interview Time Slot Received
    • Successful: To Be Update Soon
    • Acceptance: To Be Update Soon



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    Thursday, April 09, 2026

    DIY Series 102: Handheld Megaphone Speaker From School

    Handheld Megaphone Speaker From School

    Received 2 units of Handheld Megaphone Speakers from a primary school. Provided free debugging and free repair service to the school.

    Symptoms: 

    • Upon power on, there is no sound output
    Analysis:
    • Checked the battery, it is using a customised Battery Pack (18650 Li-Ion, single cell, 3.7V, 2000mA)
    • Battery pack comes with USB port for charging, but unable to charge when insert to a USB port for charging.
    Photos:
    • Unlatch and open up the back cover of Megaphone
    • Unplug the battery pack from USB Port
    • Unscrew a screw at the battery pack housing
    • Take out the old 18650 Battery from its housing (terminals joint by spot welding)
    • Disconnect the old 18650 Battery from +/- terminal wiring (spot welded)
    • Prepare nickel strip to make 2pcs of nickel plates for +/- terminal wiring spot welding
    • Clamp the nickel plates onto +/- terminal wiring using wire cutter
    • Spot welding a nickel plate onto the new 18650 Battery positive (+) terminal
    • Spot welding a nickel plate onto the new 18650 Battery negative (-) terminal
    • Reinsert the new 18650 Battery into its housing
    • Screw the housing and turn on the switch to check Battery Pack. The Red colour LED is on upon switched on, means battery is fine. Take the Battery Pack for USB charging, charge until LED turn into Blue colour.

    Tools Involved:
    Cost Involved:
    Note:
    • Current lithium-ion technology for the standard 18650 form factor (18mm x 65mm) has a physical maximum capacity limit of approximately 3500mAh to 3600mAh. 
    • Any 18650 battery claiming more than 4000mAh, including ProDIY, is generally considered by experts to be using inflated marketing specs.
    • ProDIY claimed to have 4800mAh but it is estimated the battery capacity < 2500mAh.



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