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Products => Test Equipment => Topic started by: taiteki on November 30, 2017, 05:30:03 pm

Title: [Fixed] BM235 issue no Loz DC, Voltage, ohms and diode
Post by: taiteki on November 30, 2017, 05:30:03 pm
I buyed 1 year and a half a bm235
for the first time a the dmm have a dim lcd but i doncared about that because i can read with no problems.
but some weeks ago the DMM stop to work poperly, i suppossed to be a battery problems and buy some new battery, but the issue continue.
(https://s8.postimg.org/qnirk2dkh/1_dim_lcd.jpg) (https://postimg.org/image/qnirk2dkh/)
The dmm dont work in voltage LoZ,DC, ohms and diode.

1 Loz, i put a 9V battery with arround 8,3V and got this.
(https://s8.postimg.org/c4bmion0h/5_low_z.jpg) (https://postimg.org/image/c4bmion0h/)
2 DC the same with the DC range.
(https://s8.postimg.org/ctuev0sox/2_voltage_1.jpg) (https://postimg.org/image/ctuev0sox/)

(https://s8.postimg.org/87yampp69/3_voltage_2.jpg) (https://postimg.org/image/87yampp69/)

(https://s8.postimg.org/ntfm6n69d/4_voltage_3.jpg) (https://postimg.org/image/ntfm6n69d/)
3 the ohms start with 0L but after short the terminas always show 0000.0ohms
(https://s8.postimg.org/pxzz7qv1d/6_ohms_1.jpg) (https://postimg.org/image/pxzz7qv1d/)

(https://s8.postimg.org/ius3s3n0x/7_ohms_2.jpg) (https://postimg.org/image/ius3s3n0x/)

(https://s8.postimg.org/s2kc8ujtd/8_ohms_3.jpg) (https://postimg.org/image/s2kc8ujtd/)
4 in diode always show 0.000v
(https://s8.postimg.org/ii0plzhmp/9_diode.jpg) (https://postimg.org/image/ii0plzhmp/)

some one have the same problem?

thanks and apologies for my english.
Title: Re: BM235 issue no Loz DC, Voltage, ohms and diode
Post by: retiredcaps on November 30, 2017, 07:40:42 pm
Check the soldering on the inductor.  See

https://www.youtube.com/watch?v=YM--cxT6X3k (https://www.youtube.com/watch?v=YM--cxT6X3k)
Title: Re: BM235 issue no Loz DC, Voltage, ohms and diode
Post by: taiteki on November 30, 2017, 09:39:13 pm
Thx retiredcaps  :clap:.

dont remenber that video!.

L3 disapeared.

(https://s8.postimg.org/3spis1l9d/IMG_20171130_215041.jpg) (https://postimg.org/image/3spis1l9d/)

(https://s8.postimg.org/vg286f1dt/IMG_20171130_221649.jpg) (https://postimg.org/image/vg286f1dt/)

i put a new ferrite bead and
 :-/O
(https://s8.postimg.org/57r3h0epd/IMG_20171130_223101.jpg) (https://postimg.org/image/57r3h0epd/)

 :-DMM
Title: Re: BM235 issue no Loz DC, Voltage, ohms and diode
Post by: retiredcaps on November 30, 2017, 10:12:41 pm
L3 disapeared.
I wonder if this L3 will be a long term problem?  You are the 3rd or 4th person to have this bad soldering problem.

BTW, for the LCD contrast Dave did a video too.

https://www.youtube.com/watch?v=rOdjN8ROrNI (https://www.youtube.com/watch?v=rOdjN8ROrNI)
Title: Re: [Fixed] BM235 issue no Loz DC, Voltage, ohms and diode
Post by: retiredcaps on November 30, 2017, 10:16:15 pm
We are also finding out that on some older Fluke 17x series, the soldering on that inductor/ferrite bead has aslo degraded or shook loose due to abuse?  However, this is over several years, possibly one decade.

https://www.eevblog.com/forum/repair/fluke-179-repair/ (https://www.eevblog.com/forum/repair/fluke-179-repair/)

https://www.eevblog.com/forum/repair/fluke-179-not-working/ (https://www.eevblog.com/forum/repair/fluke-179-not-working/)

https://www.eevblog.com/forum/repair/fluke-179-76688/ (https://www.eevblog.com/forum/repair/fluke-179-76688/)
Title: Re: [Fixed] BM235 issue no Loz DC, Voltage, ohms and diode
Post by: retiredcaps on November 30, 2017, 10:23:42 pm
Thread for dim lcd on BM235.

https://www.eevblog.com/forum/testgear/eevblog-brymen-bm235-lcd-issues-or-normal/ (https://www.eevblog.com/forum/testgear/eevblog-brymen-bm235-lcd-issues-or-normal/)
Title: Re: [Fixed] BM235 issue no Loz DC, Voltage, ohms and diode
Post by: joeqsmith on December 01, 2017, 12:04:12 am
Mine had a notch cut out I assume for this reason.

https://youtu.be/g3uYcHAumhA?t=436
Title: Re: [Fixed] BM235 issue no Loz DC, Voltage, ohms and diode
Post by: taiteki on December 01, 2017, 06:32:16 pm
Thxs for the links.

in the case of this DMM it was in a non climatized zone, 40ºC-45ºC in summer and 8ºC-20ºC winter (Seville-Spain).

Possibly it has been damaged for a long time, since I have only used it to measure current.

in the image of my dmm it seems that the ferrite bean broke apart.

(https://s8.postimg.org/m2jq2l301/comparation_bm235_b.jpg) (https://postimg.org/image/m2jq2l301/)