Uploaded October 2024 | Updated September 2026, 2 days ago
Last time I teared down that dead ultrasonic cleaner, now we repair it …
↓↓↓ Complete description, time index and links below ↓↓↓
WARNING: This video involves AC mains, which can cause serious injury or death! Do not try to recreate anything shown in this video unless you are qualified.
In the previous video I teared down that dead ultrasonic cleaner and did a failure analysis (link below). My conclusion was that the half-bridge power MOSFETs and the half-bridge gate driver were gone for good. Now I have the spare parts.
I start out desperately trying to get that half-bridge driver to work again, but fail miserably. After finally realizing that the driver’s charge pump doesn’t work without the low-side MOSFET, it’s smooth sailing and soon after the unit works again.
00:00 Intro – I got spares, so let’s do some repairs
00:53 Measuring 7 – charge pump capacitor, 15V rail
03:38 Replacing 1 – new MOSFET driver, but no luck
04:22 Measuring 8 – (Zener) diodes limiting gate voltage
07:05 AC/DC coupling – of oscilloscope is irrelevant
07:46 Measuring 9 – charge pump diode/capacitor voltage
08:54 Charge pump – the case of the missing component
12:10 Replacing 2 – new half-bridge low-side MOSFET
12:47 Measuring 10 – half-bride high-side gate voltage
13:10 Replacing 3 - new half-bridge high-side MOSFET
13:43 Measuring 11 – full-bridge rectifier under load
15:48 Replacing 3 – the old, but OK full-bride rectifier
16:19 Reassembly – putting everything back together
18:40 Test – finally success, it’s alive again
20:09 Wrap-up – next week will be the usual, bye
Teardowns youtube.com/playlist?list=PLwq-2MnM58FJPg01ooMBgy_CxDxAem0my
Repairs youtube.com/playlist?list=PLwq-2MnM58FIAycsmi3ZCjHmfGK3Tev7m
EMAG Emmi-12HC Ultrasonic Cleaner – Teardown and Fault Analysis youtu.be/onJxjlORC7I
Auxiliary Negative Rail for Linear Power Supply (Charge Pump, Voltage Doubler) youtu.be/3gHIhTkI4Co
Small Project: AC Mains Isolation Transformer from Two Broken UPSs (1/2) youtu.be/SlTDqRNryuM
Small Project: AC Mains Isolation Transformer from Two Broken UPSs (2/2) youtu.be/SmCYR4FNrSs
#emag #emmi #ultrasoniccleaner #teardown #disassembly #disassembling #repair #fix #robertssmorgasbord
Last time I teared down that dead ultrasonic cleaner, now we repair it …
↓↓↓ Complete description, time index and links below ↓↓↓
WARNING: This video involves AC mains, which can cause serious injury or death! Do not try to recreate anything shown in this video unless you are qualified.
In the previous video I teared down that dead ultrasonic cleaner and did a failure analysis (link below). My conclusion was that the half-bridge power MOSFETs and the half-bridge gate driver were gone for good. Now I have the spare parts.
I start out desperately trying to get that half-bridge driver to work again, but fail miserably. After finally realizing that the driver’s charge pump doesn’t work without the low-side MOSFET, it’s smooth sailing and soon after the unit works again.
00:00 Intro – I got spares, so let’s do some repairs
00:53 Measuring 7 – charge pump capacitor, 15V rail
03:38 Replacing 1 – new MOSFET driver, but no luck
04:22 Measuring 8 – (Zener) diodes limiting gate voltage
07:05 AC/DC coupling – of oscilloscope is irrelevant
07:46 Measuring 9 – charge pump diode/capacitor voltage
08:54 Charge pump – the case of the missing component
12:10 Replacing 2 – new half-bridge low-side MOSFET
12:47 Measuring 10 – half-bride high-side gate voltage
13:10 Replacing 3 - new half-bridge high-side MOSFET
13:43 Measuring 11 – full-bridge rectifier under load
15:48 Replacing 3 – the old, but OK full-bride rectifier
16:19 Reassembly – putting everything back together
18:40 Test – finally success, it’s alive again
20:09 Wrap-up – next week will be the usual, bye
Teardowns youtube.com/playlist?list=PLwq-2MnM58FJPg01ooMBgy_CxDxAem0my
Repairs youtube.com/playlist?list=PLwq-2MnM58FIAycsmi3ZCjHmfGK3Tev7m
EMAG Emmi-12HC Ultrasonic Cleaner – Teardown and Fault Analysis youtu.be/onJxjlORC7I
Auxiliary Negative Rail for Linear Power Supply (Charge Pump, Voltage Doubler) youtu.be/3gHIhTkI4Co
Small Project: AC Mains Isolation Transformer from Two Broken UPSs (1/2) youtu.be/SlTDqRNryuM
Small Project: AC Mains Isolation Transformer from Two Broken UPSs (2/2) youtu.be/SmCYR4FNrSs
#emag #emmi #ultrasoniccleaner #teardown #disassembly #disassembling #repair #fix #robertssmorgasbord
