Defective Motor Found In Nais Massager EV297
This Nais Massager EV207 was brought to me by my close friend, with the complaint that it was dead and has been lying unused for a very long time. On checking its external adapter, I found that it was working. I opened the set and did not find any dust or dirt inside it, except the battery leakages. Have a look at the snaps taken:
So, desoldered the wires and cleaned the PCB thoroughly. The battery was completely dead and found to have leaked its ‘juice’! After that I applied power only to the motor to check whether it was rotating. It was dead. So opened the head and removed the motor for checkup.
There was no continuity, indicating that either the contacts are bad or coil was open. I pried open the bottom of the motor to look into. One of the contacts had broken off and fallen down inside the motor.
What I did was removing the broken stub from its housing, cleaning it thoroughly and scraping it to enable soldering. Scraped the end of the broken piece also well for this purpose. Then fixed it back, kept the broken piece in position, applied Fevibond and after it dried a bit, applied Superglue over it and allowed it to get fixed properly. Then scraping once again, soldered the joints very well so that it had bonded well. Applied a bit of Fevibond on top of it so that it stays protected and in place. Put the armature back inside, inserting a tweezer through the bottom plate holes (meant for this purpose, while assembling) to keep away the contacts and avoid its getting jammed or damaged by the armature.
Fixed the bottom cover and applied power. It worked very well! Unfortunately, I forgot to click these very interesting stages. Fixed the motor back in its hood. Applied power and found it was vibrating like thunder! Turned my attention to the board. Checked and found that all components were ok, except the switch. Luckily, this switch had screws underneath. So opened it. Just see the amount of leakage of battery that had gone into it:
Cleaned it thoroughly in the wash basin, using detergent powder and water. Dried it using Hair Drier. Cleaned it further using spirit. Cleaned and scraped the contacts very well. Fixed it back and found it was working perfectly, when checked in Analogue Multimeter.
Got a replacement for the battery and connected the PCB back to its original condition. Applied power and found it to be charging and massager functional.
Here, you can have a look at this after finishing the work:
Another excellent job done and saved it to my satisfaction bag!
My friend was very happy that he could get it working again. As I had bought the battery on his account, I treated this as a ‘gift’ service!
This article was prepared for you by Parasuraman Subramanian from India. He is 69 years old and has more than 30 years’ experience in handling antique equipment like Valve Radio, Amps, Reel Tape Recorders and currently studying latest tech-classes conducted by Kerala State Electronics Technicians’ Association. He has done graduation in BBA degree, private diploma in Radio Engineering and retired as MD of a USA company. Presently working as Consultant to Hospital and other institutions.
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You may check on his previous repair article below:
https://jestineyong.com/burst-capacitor-and-vertical-failure-in-tv-after-lightning-strike/
Albert van Bemmelen
February 22, 2019 at 4:49 pm
I was unfamiliar with Fevibond. And a search on Aliexpress didn't give any result either. But on eBay it is sold as: 25ML X Fevibond Synthetic Rubber Base Glue Multi -purpose Adhesive. (Maybe it is comparable what is known in my country as Bisontix to glue shoe soles?). Apparently it is often being used instead of hotmelt glue too. Good to know, thanks!
Robert Calk Jr.
February 23, 2019 at 6:43 am
Hi Albert. I would make sure that it is not acidic before I used it.
Albert van Bemmelen
February 23, 2019 at 2:47 pm
Yes, I know what you mean. Something that the use of Hotmelt has in favor since it hardly produces any chemical reaction! Only its higher applying temperature could be a problem.
Robert Calk Jr.
February 23, 2019 at 6:42 am
Good job, Parasuraman.
Robert Calk Jr.
February 23, 2019 at 6:58 am
I just ordered myself some Fevibond from India. I will give it a try.
Parasuraman S
February 25, 2019 at 12:37 pm
This is a rubber based glue that takes a little longer time to bond. We need to clean both the surfaces and apply a thin coat on both sides, allow it a few seconds to dry and then press together. If we apply superglue after that, it will remain well bonded and fairly strong enough.
Humberto
February 27, 2019 at 1:22 am
Good repair, Parasuraman