Brymen BM257 calibration error 'C_Er' - Page 1
Forum section: electronics / testgear

author: Gabri74
author_rank: Regular Contributor
timestamp: February 01, 2024, 04:26:39 pm
content: Just happened the same problem as describe in another old thread:https://www.eevblog.com/forum/testgear/brymen-257s-lost-calibration-data/Today to my BM257 had a sudden low-battery warning, display flickers, meter power off itself and the the 'C_Er' message is displayed :'(Tried entering/exiting calibration mode procedure to reset the error as suggested in the above thread without success.Can anyone suggest where to send it to calibrate from Italy ?Moreover, will it be worth to calibrate it ? I don't know how much could it cost, but the meter is several years old and if it's too expensive I'll probably buy a new one.Thanks in advance

author: J-R
author_rank: Super Contributor
timestamp: February 01, 2024, 06:41:19 pm
content: What if you do the first calibration step for resistance (short), then power cycle?

author: Gabri74
author_rank: Regular Contributor
timestamp: February 02, 2024, 09:24:04 am
content: Thanks for your suggestion.Followed this procedure:1) Turn Rotary Knob to "OFF" position.2) Press and hold "SELECT" and "HOLD" buttons, and then turn "Rotary Switch" from "OFF" to "" function position within one second.3) "000.0" is displayed4) Input 000.0, press "SELECT" and then "REL" buttons simultaneously5) Wait till reading is stable, press "SELECT" and then “HOLD” buttons simultaneously.6) “300.0” is displayedI had to do it several times, because on the first tries at point 6) (after pressing select+hold) it was showing and empty display with the 'nF' symbol only instead of 300.0 ohm.After several retries it worked, but instead of going to 300.0 as shown in point 6), it went straight to 30.000K...And now my ohm range is broken: when shorting, it shows 1.000K and 1.500K intermittently :'(I think I screwed up the calibration completely...

author: mwb1100
author_rank: Frequent Contributor
timestamp: February 02, 2024, 08:03:40 pm
content: welectron offerscalibration for Brymen metersfor 60 EUR + VAT + shipping. (BM780/BM850s/BM860sis 10 or 15 EUR more)They sellBM257s metersfor 90 Eur + VAT + shipping (I think shipping is 10 EUR within the EU), so the cost of calibration is pretty close to getting a new meter (since you'd have to pay to ship your meter to them).If you do order from them, ask them for the EEVBlog discount (5% I think).

author: J-R
author_rank: Super Contributor
timestamp: February 03, 2024, 03:02:30 am
content: I think you just went too far in the procedure and entered the 300 Ohm calibration point. Can you find a 300 Ohm resistor to fix that mode?Or are you saying it doesn't ever show the 300 Ohm calibration point any more?If so, it does sound like it has bad flash memory, so it would have been a lost cause anyway.

author: Gabri74
author_rank: Regular Contributor
timestamp: February 03, 2024, 03:51:25 pm
content: I've contacted Brymen Europe and they suggested the same procedure as I did :-)After telling them what went wrong, they offered to check the meter and (if possible) to fix the calibration, I'll need to pay only shipping expensesI must say I'm really impressed by the Brymen customer care service, the replied to my email in minutes and on Monday I'm shipping the meter to Poland.I'll keep this thread updated if someone happen to have the same problem.Thanks for the help.