Oral B Toothbrushes - Page 1
Forum section: electronics / repair

author: Northy
author_rank: Regular Contributor
timestamp: September 26, 2020, 08:17:06 pm
content: Hi,I've got two now that are dead.Both Type 3756I've opened them both up, they were very cruddy inside. I've cleaned them off with IPA.One won't charge. When you put it on the charger the top red LED lights up bright, and the charge LED very dim.One started one morning randomly turning itself on! I let the battery run flat. It seems to charge, but now it won't turn on. I think I got it to turn on once since having it apart, but not any more.Has anyone ever fixed one?Any ideas?Thanks,G

author: Northy
author_rank: Regular Contributor
timestamp: September 26, 2020, 08:42:16 pm
content: I've been doing some debugging.The switch is good.There's a step up supply giving 3V out.The FET isn't being turned on.There's an MSP430 in there.

author: bob91343
author_rank: Super Contributor
timestamp: September 26, 2020, 09:53:51 pm
content: I use the Sonocare. Except when the NiCd battery failed due to age, it has been fine. However, it's not possible to nondestructively open it to replace the battery.So I called the company and bought another unit with assurance that it would fit the charger. Well, it didn't. So I called to complain and told them they promised it would fit. The reason it wouldn't fit is that there was a plastic keyway in the old charger preventing insertion of the new head.I said no big deal because I can modify the charger so it will fit, just grind off the key with my Dremel. They went into panic mode and said NO NO DO NOT MODIFY THE CHARGER! They said they will send me a new charger free. So they did but in the interim I modified the charger and it works fine. I put it away and have been using the new one.It seems that unnecessary things are often done for the wrong reasons. Everyone is so afraid of litigation that they cause more problems than they solve.

author: Technomaniac
author_rank: Contributor
timestamp: September 26, 2020, 10:42:11 pm
content: Too lazy to move a toothbrush back and forth by hand, but I bet you waste energy exercising on electric treadmills.The last Oral B toothpaste I bought and am currently using, came with a new snap type lid. To snap it shut you need to grip the tube and lid in such a way that I reckon the tube will crack where tube joins to the top before you're halfway used up. But I love the toothpaste.

author: SilverSolder
author_rank: Super Contributor
timestamp: September 27, 2020, 12:07:36 am
content: There is an Oral-B version that uses 2xAA batteries. It doesn't cost much. I put 2 rechargeable Eneloops in there, and - as you'd expect - they are nearly indestructible.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: September 27, 2020, 02:41:53 am
content: Quote from: Technomaniac on September 26, 2020, 10:42:11 pmI use to be in your camp, but my dentist told me; "With all my knowledge of tooth morphology and training on brushing, I can't get the results from manual brushing that you get with an electric toothbrush". That convinced me to try the electric route and subsequent dental exams seemed to show that he was right. I still actually like manual brushing better, but use the electric toothbrush except when I am traveling.Can't help the OP. I see no way to non-destructively open the toothbrush.

author: richnormand
author_rank: Unknown
timestamp: September 27, 2020, 02:57:18 am
content: On my Oral-B there is a plastic knob on the back of the charge stand that is designed to fit in the bottom of the brush wand.A quarter turn will allow you to open it. Then you push on the brush tip and it will all come out.Batteries are available many places and after a bit of cleaning of the corrosion it has been working well.Think to watch for are the charging coil wires and corrosion affecting the charge circuit due to leakage..

author: james_s
author_rank: Super Contributor
timestamp: September 27, 2020, 02:59:11 am
content: I had one of the original Sonicare brushes too, same issue with the original battery failing after about 8 years. After that I bought one of the Philips Sonicare models, it was much cheaper at only about $20 and it uses a pair of ordinary AA cells. I've been running NiMH cells in it since I bought it around a decade ago and it has been great.

author: Northy
author_rank: Regular Contributor
timestamp: September 27, 2020, 07:50:39 am
content: No treadmills hereI've already got them both apart.I'm going to connect the one that won't charge to a bench supply.The other one I'm a bit stumped on. All seems to look ok but the FET isn't getting enabled.G

author: james_s
author_rank: Super Contributor
timestamp: September 27, 2020, 06:31:30 pm
content: Quote from: CatalinaWOW on September 27, 2020, 02:41:53 amMy dentist told me the same thing, and I saw similar results. I also prefer brushing manually but it is undeniable that the Sonicare does a better job cleaning my teeth, it has made a dramatic improvement in my dental health.

author: SilverSolder
author_rank: Super Contributor
timestamp: September 27, 2020, 10:47:54 pm
content: Same here. The problem with modern advertising is that you tend not to believe it, even if it is true!

author: Northy
author_rank: Regular Contributor
timestamp: September 30, 2020, 03:24:09 pm
content: I gave up, not worth my time. Ordered two that run from AA batteries for £6.50 each!G