Brymen BM 235 Startup issues

[wraper]

Hi,

I already tried that, pressing some of the buttons during startup with both, alkalines and eneloops. Same result: 2 times of 10, the meter with eneloops is stuck in the boot process, with alkalines the meter pulls through every single time.

I have to correct myself, the eneloops are older than a year, it was my second batch bought in September 2017, so we are talking about 2 years now. My fault!

Attach to lab PSU instead and try switching it on with different voltages. In any case, hanging on startup is failure. If batteries provide too low voltage, it still should not hang on power on.

[Specmaster]

2 or 3 times and then not used for while fail next time they are charged with error codes on the battery charger

Sounds like your charger is (probably faulty) crap. It's your charger what fails, not batteries  .

Not really, because I have a number of different chargers, and is the SAME batteries that fail each time with any of the chargers.

[wraper]

Not really, because I have a number of different chargers, and is the SAME batteries that fail each time with any of the chargers.

Unless you bought some extraordinary crappy batteries, this sounds really strange.

[Ohm]

https://www.eevblog.com/forum/testgear/fluke-289-meter/ Somehow my name got change from dab147315 but this was my first post and change all my meters over to lithium batteries and no problem with that Fluke 289 to this point.

[paulbt]

Hi, everyone !

I recently bought a Brymen 235 and while I was playing around with it, I was curious if it has any power-on options like Flukes. The only thing that I found was while holding "HOLD" button when turning on - it displayed "9". The manual does not mention anything about this. Does anybody knows what it means?

[jordanp123]

My BM235 just started doing the same thing. Although I can't even get mine to fully boot. It'll just come up to the start up screen with the display test and never leave. If I up the voltage it'll eventually give me the inEr message and beep but thats all. This was actually a spare meter I bought for just in the occasions I needed multiple meters....which was yesterday. Any one have any ideas?

[slburris]

In fact my BM235 is displaying the same symptoms.  Changed to fresh batteries, no dice, hangs in bootup.  So sad that it's
having problems -- it hasn't been abused in any way, but it's broken now.  Does the firmware bit rot over time?  Who knows.  When I press the HOLD key at power up, it displays "C", so it's not fully dead.

Oh well, guess I'll use my Fluke meter for now, as I am not up to trying to troubleshoot this down to the component level right now.

[J-R]

Surely the first step is take it apart and clean the wipers and contacts?

[cbianco]

My EEVBlog BM235 just started doing the same thing as well: it starts up, but gets stuck on the LCD test screen and is completely unresponsive.  If I hold down the HOLD key at startup, mine shows 9, which I think is just the firmware version.

I tried fresh batteries, checked fuses, took it apart, did a visual inspection of the board, cleaned the wipers & contacts, and scoured google for solutions.  This thread seems is the only place where I found the same issue mentioned, so adding my observations:

I found a highly impractical workaround, at least for my case: I noticed is that if I hooked it up to a DC power supply, and LOWERED the voltage to about 2.1 volts, it started up normally (albeit with a low battery warning and a dim screen)...  Turning the voltage back up to 3V got it behaving properly as far as I can tell, but the problem returned after powering it off.  I could also get it to start up properly if I very briefly disconnected the battery (probably because that briefly dropped the voltage via some partially-discharged capacitor)... so maybe the problem has to do with some transient voltage during startup(?) - maybe a capacitor that' s not charging?  I'm a mech eng, so out of my depth with this stuff, but maybe that can help someone smarter than me to properly diagnose the problem...

[wraper]

^Seems more like it fails some sort of self testing but lowering the voltage lets it pass. Try to get it working and check if all functions are within spec to possibly narrow down the issue.

[cbianco]

thanks for the suggestion!  I tested every function I could (AC/DC voltage, current, resistance, capacitance, diode), and once I get it to start, everything seems to work fine - at least within the limits of my crude testing equipment.

I found another way to get it to start up properly: if I cool it down (ie: in my freezer), it works without issue - other than the sluggish LCD.  I tried this with a 3V DC power supply (so nothing to do with cold batteries), and didn't have to drop the voltage to get it to start up normally.  Once it's back up to room temperature, the problem is back.