Products > Test Equipment

Brymen BM86x Backlight Duration Mod

<< < (5/5)

IanB:

--- Quote from: joeqsmith on March 06, 2024, 01:42:16 pm ---Brymen:

--- Quote ---... BM869s uses OTP chip. Its firmware can not be updated directly. The only way is to replace its U6. To change U6 may have the chance to affect its performance. Generally re-calibration and retest are recommended after replacing chip. ....
--- End quote ---

--- End quote ---


--- Quote from: shakalnokturn on March 06, 2024, 05:11:50 pm ---That only makes half sense to me:
Calibration constants can't be in OTP MCU (at the best they could store coarse default values) and various photos show EEPROMs, replacing the MCU is not replacing the ADC so their comment is true only if the new firmware uses different EEPROM addresses for calibration.

--- End quote ---

If you disassemble the meter, unsolder a chip, and solder in a new chip, that is major surgery on the meter. If you want to trust the meter after such work, it would clearly be sensible to do a re-calibration and retest. It's a recommendation, not a requirement.

joeqsmith:

--- Quote from: IanB on March 06, 2024, 06:02:43 pm ---
--- Quote from: joeqsmith on March 06, 2024, 01:42:16 pm ---Brymen:

--- Quote ---... BM869s uses OTP chip. Its firmware can not be updated directly. The only way is to replace its U6. To change U6 may have the chance to affect its performance. Generally re-calibration and retest are recommended after replacing chip. ....
--- End quote ---

--- End quote ---

If you disassemble the meter, unsolder a chip, and solder in a new chip, that is major surgery on the meter. If you want to trust the meter after such work, it would clearly be sensible to do a re-calibration and retest. It's a recommendation, not a requirement.

--- End quote ---

Agree.  During that video, after swapping the part, I run through the same basic checks and didn't notice it having any effect on the measurements.   

***

--- Quote ---The only option would be to buy a new meter from current production.
--- End quote ---
That video is 3 years old.  I am a bit surprised that someone with a older meter would necropost about it today.
***

--- Quote from: shakalnokturn on March 06, 2024, 05:11:50 pm ---That only makes half sense to me:
Calibration constants can't be in OTP MCU (at the best they could store coarse default values) and various photos show EEPROMs, replacing the MCU is not replacing the ADC so their comment is true only if the new firmware uses different EEPROM addresses for calibration.

--- End quote ---

Calibration constants have nothing to do with the backlight timer, which is hard coded in the firmware.   Calibration does not suggest realignment.  As IanB mentions, calibration was only recommended to make sure the meter was still functioning. 


--- Quote from: Fungus on March 05, 2024, 01:46:03 pm ---Add a flip-flip to the LED circuit so that pushing the backlight button toggles it on/off.

--- End quote ---

I like my auto dimming backlight on my UT61E. 

https://youtu.be/S36LfKmSjKw?t=332

Navigation

[0] Message Index

[*] Previous page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod