EEVblog BM235 Not Beeping Anymore - Page 1
Forum section: electronics / testgear

author: vitormhenrique
author_rank: Unknown
timestamp: August 05, 2016, 03:41:44 am
content: What's up guys,I have a question, my EEVblog BM235 stopped beeping all of a sudden, since yesterday it does not make any sound, neither on continuity test, or putting the probes incorrectly (like inserting it on current and putting the meeter on volts).Is there something really silly that I'm missing? like a mute function that I activated? I looked on the manual and did not find any thing related with a mute function. Note that everything else looks fine, measuring voltage, current, even continuity is fine, the screen still flash.Or is something wrong with my BM235?Thank you all!Vitor Henrique

author: retiredcaps
author_rank: Super Contributor
timestamp: August 05, 2016, 04:11:54 am
content: Quote from: vitormhenrique on August 05, 2016, 03:41:44 amPossibly. Can you take a clear focused photo of the beeper and its surrounding area? Something like Dave's picture athttps://www.flickr.com/photos/eevblog/24689654432but, obviously, we want to see yours for possible damage.You may have a weak solder joint, dislodged component, bad component and/or bad beeper.

author: Owen
author_rank: Contributor
timestamp: August 05, 2016, 05:45:47 am
content: The BM235 slowly becomes a show stopper. How many had issues? 5 or so? Brymen definitely needs a better quality control on that one. First Backlight noise, second lcd contrast issue, than broken Ls, solder joints... If I would buy one at least now I would think when my first issues appears.No i'm not a Brymen hater or something, i have 3 Brymens... So i feel a bit worried abour their reputation for now on 😖.

author: Whales
author_rank: Super Contributor
timestamp: August 05, 2016, 07:07:30 am
content: Tried changing the batteries?

author: Hydrawerk
author_rank: Super Contributor
timestamp: August 05, 2016, 05:12:59 pm
content: Check the black buzzer. There should be a 50 Ohm resistance.

author: Kilrah
author_rank: Unknown
timestamp: August 05, 2016, 06:25:55 pm
content: Quote from: Owen on August 05, 2016, 05:45:47 am5 out of how many hundreds? Come on...

author: vitormhenrique
author_rank: Unknown
timestamp: August 05, 2016, 07:59:46 pm
content: I'll measure the resistance and take some pictures tonight!And yes, I changed the batteryThanks for the help guys!

author: vitormhenrique
author_rank: Unknown
timestamp: August 06, 2016, 01:21:52 am
content: So I just took apart my multimeter, tested resistance of the Piezo and it did not show anything.Removed the piezo from the PCB and tested the diode continuity, nothing. As you can see from the pictures, it does not look like anything went wrong with my BM235.I had a Piezo lying around and replaced the original, and voalá, started beeping again. Probably the replaced Piezo does not have the same rating form the original, so I'm not sure that it is a smart decision to keep it there, it definitely does not sound like the original.I'm attaching a image of the original piezzo, do you guys know where can I find a similar one?

author: Hydrawerk
author_rank: Super Contributor
timestamp: August 06, 2016, 02:59:03 am
content: Is it really a piezo? Isn't it a little dynamic speaker with a coil inside?

author: vitormhenrique
author_rank: Unknown
timestamp: August 06, 2016, 06:55:07 am
content: Quote from: Hydrawerk on August 06, 2016, 02:59:03 amNot sure, I'll open the component tomorrow and analyze what is inside.

author: Whales
author_rank: Super Contributor
timestamp: August 06, 2016, 11:34:46 am
content: Quote from: vitormhenrique on August 06, 2016, 06:55:07 amIndeed both come in an identical looking package.

author: Hydrawerk
author_rank: Super Contributor
timestamp: August 06, 2016, 04:23:28 pm
content: Quote from: blueskull on August 06, 2016, 03:22:38 amSorry, what is a MSRP scope??I could only find that MSRP meansmanufacturer's suggested retail price.

author: Kilrah
author_rank: Unknown
timestamp: August 06, 2016, 04:31:40 pm
content: You got it then. The whole point is that an expensive scope failed.

author: zapta
author_rank: Super Contributor
timestamp: August 06, 2016, 05:35:42 pm
content: Quote from: Hydrawerk on August 06, 2016, 04:23:28 pmI also have a MSRP scope. Different model number though. It's from the $4xx series.

author: vitormhenrique
author_rank: Unknown
timestamp: August 08, 2016, 02:34:25 pm
content: Quote from: Whales on August 06, 2016, 11:34:46 amDefinitely a piezo on my opinion.

author: Fungus
author_rank: Super Contributor
timestamp: August 08, 2016, 03:34:43 pm
content: Quote from: Hydrawerk on August 06, 2016, 04:23:28 pmYou understood it perfectly.

author: PedroDaGr8
author_rank: Super Contributor
timestamp: August 08, 2016, 08:26:40 pm
content: Quote from: Hydrawerk on August 06, 2016, 04:23:28 pmRead it as ($15k MSRP) Scope, not $15K (MSRP Scope).

author: Gyro
author_rank: Super Contributor
timestamp: August 08, 2016, 09:08:58 pm
content: Quote from: vitormhenrique on August 08, 2016, 02:34:25 pmI wonder what the failure mode was, there isn't exactly much to go wrong with a piezo. Contamination of the spring contact points (flux or wash)? Overheating during assembly causing loss of spring pressure (melted plastic)? Corrosion in storage or use?I bet it would work again if you cleaned and reassembled it.

author: Muxr
author_rank: Super Contributor
timestamp: August 08, 2016, 09:32:27 pm
content: bad contact perhaps..