# Warning - JLCPCB & Module V4.40 and part D2 **URL:** \ **Category:** diyBMS\ **Created:** [12 March 2021 08:09 UTC](https://community.openenergymonitor.org/t/warning-jlcpcb-module-v4-40-and-part-d2/17176 "2021-03-12T08:09:52Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![stuart](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/stuart/32/16661_2.png) [@stuart](https://community.openenergymonitor.org/u/stuart)\ **Post date:** [12 March 2021 08:09 UTC](https://community.openenergymonitor.org/t/warning-jlcpcb-module-v4-40-and-part-d2/17176/1 "2021-03-12T08:09:52Z")
I’ve had a few people contact me about V4.40 orders they have placed with JLCPCB. In production JLC are sometimes swapping part D2 around (rotating it). If you have ordered from JLCPCB, please check any boards you have had made. The D2 part should be like in the picture, with the “stripe” towards the right handside of the board, near the “+” sign. Definitely check before applying power to the module, as an incorrectly orientated diode will cause a dead short across the terminals, probably leading to the fuse going, or something melting!! There is also a GitHub issue open for more information. [Issue 73](https://github.com/stuartpittaway/diyBMSv4/issues/73) If you do have boards which are incorrectly built, you have two options: 1. Remove D2 completely (unsolder it), this also means you lose the “voltage spike” protection this part provides 2. Unsolder D2 and rotate it, and re-solder it (recommended) The part is quite large, so not difficult to unsolder with a normal iron. A correct board looks like this: ![image](https://community.openenergymonitor.org/uploads/default/original/3X/5/4/54d83df5b6c7ad460886eaaa152ffa8d4a1ecbc4.png) ---
**Author:** ![voltmeter](https://community.openenergymonitor.org/letter_avatar_proxy/v4/letter/v/9de053/32.png) [@voltmeter](https://community.openenergymonitor.org/u/voltmeter)\ **Post date:** [16 March 2021 12:57 UTC](https://community.openenergymonitor.org/t/warning-jlcpcb-module-v4-40-and-part-d2/17176/2 "2021-03-16T12:57:40Z")
@stuart Wrong D2 orientation? what do you think? this is the ordered (first file with old resistors) ![v4.4](https://community.openenergymonitor.org/uploads/default/original/3X/7/9/79ad6a46fb24983ff5474160005ab0fce08b3322.png) and this the delivered ![20210316_134811](https://community.openenergymonitor.org/uploads/default/original/3X/a/3/a3c1b48c58e93e171ba0c48bc708b2fdbe3d16d0.jpeg) ---
**Author:** ![donnib](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/donnib/32/11015_2.png) [@donnib](https://community.openenergymonitor.org/u/donnib)\ **Post date:** [16 March 2021 13:13 UTC](https://community.openenergymonitor.org/t/warning-jlcpcb-module-v4-40-and-part-d2/17176/3 "2021-03-16T13:13:13Z")
Looks nice, the temp sensor you break off then solder cables to the module itself i pressume ? I was thinking ordering a small board like that just for that purpose since soldering cables to a SMD component is just messy. What’s with the hole on the module ? For cooling ? ---
**Author:** ![voltmeter](https://community.openenergymonitor.org/letter_avatar_proxy/v4/letter/v/9de053/32.png) [@voltmeter](https://community.openenergymonitor.org/u/voltmeter)\ **Post date:** [16 March 2021 13:17 UTC](https://community.openenergymonitor.org/t/warning-jlcpcb-module-v4-40-and-part-d2/17176/4 "2021-03-16T13:17:18Z")
its the new version v4.4 watch stuarts video on youtube ---
**Author:** ![donnib](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/donnib/32/11015_2.png) [@donnib](https://community.openenergymonitor.org/u/donnib)\ **Post date:** [16 March 2021 13:18 UTC](https://community.openenergymonitor.org/t/warning-jlcpcb-module-v4-40-and-part-d2/17176/5 "2021-03-16T13:18:50Z")
Got it, i just looked it up in the repo. ---
**Author:** ![stuart](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/stuart/32/16661_2.png) [@stuart](https://community.openenergymonitor.org/u/stuart)\ **Post date:** [16 March 2021 13:25 UTC](https://community.openenergymonitor.org/t/warning-jlcpcb-module-v4-40-and-part-d2/17176/6 "2021-03-16T13:25:23Z")
THAT IS WRONG ORIENTATION! ## DO NOT CONNECT THOSE MODULES TO ANY CELL/VOLTAGE! You need to ROTATE D2 part - un solder it and rotate so the “stripe” is on the right handside. Thank you for posting the pictures. ---
**Author:** ![stuart](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/stuart/32/16661_2.png) [@stuart](https://community.openenergymonitor.org/u/stuart)\ **Post date:** [16 March 2021 13:35 UTC](https://community.openenergymonitor.org/t/warning-jlcpcb-module-v4-40-and-part-d2/17176/7 "2021-03-16T13:35:44Z")
@voltmeter can you tell me if the D2 part was out of stock when you ordered? It seems that people are picking a different part, and JLCPCB have different orientations of that same part! ---
**Author:** ![voltmeter](https://community.openenergymonitor.org/letter_avatar_proxy/v4/letter/v/9de053/32.png) [@voltmeter](https://community.openenergymonitor.org/u/voltmeter)\ **Post date:** [16 March 2021 13:41 UTC](https://community.openenergymonitor.org/t/warning-jlcpcb-module-v4-40-and-part-d2/17176/8 "2021-03-16T13:41:35Z")
no it was in stock was the original like in the bom file C440263 ive ordered right after your v4.4 video release ---
**Author:** ![stuart](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/stuart/32/16661_2.png) [@stuart](https://community.openenergymonitor.org/u/stuart)\ **Post date:** [16 March 2021 13:45 UTC](https://community.openenergymonitor.org/t/warning-jlcpcb-module-v4-40-and-part-d2/17176/9 "2021-03-16T13:45:57Z")
> [@voltmeter](#): > > C440263 Thanks, unfortunately as per this forum topic, there is a lot of confusion on this particular part, sometimes JLC place it 180 degrees, sometimes zero degrees. Unfortunately for you, you will need to unsolder and flip it over, or just remove it completely. Don’t connect to a cell before doing this - otherwise it creates a dead short. ---
**Author:** ![voltmeter](https://community.openenergymonitor.org/letter_avatar_proxy/v4/letter/v/9de053/32.png) [@voltmeter](https://community.openenergymonitor.org/u/voltmeter)\ **Post date:** [16 March 2021 13:49 UTC](https://community.openenergymonitor.org/t/warning-jlcpcb-module-v4-40-and-part-d2/17176/10 "2021-03-16T13:49:34Z")
if i remove it, is the fuse stil working? i think i dont need it because i have not higher voltage than 4.2V per module, if its higher then the module is not my problem anymore 🙃 ---
**Author:** ![atanisoft](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/atanisoft/32/14690_2.png) [@atanisoft](https://community.openenergymonitor.org/u/atanisoft)\ **Post date:** [16 March 2021 13:57 UTC](https://community.openenergymonitor.org/t/warning-jlcpcb-module-v4-40-and-part-d2/17176/11 "2021-03-16T13:57:16Z")
> [@voltmeter](#): > > if i remove it, is the fuse stil working? The fuse is inline with the + voltage ahead of the diode. It will continue to work. ---
**Author:** ![stuart](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/stuart/32/16661_2.png) [@stuart](https://community.openenergymonitor.org/u/stuart)\ **Post date:** [16 March 2021 13:59 UTC](https://community.openenergymonitor.org/t/warning-jlcpcb-module-v4-40-and-part-d2/17176/12 "2021-03-16T13:59:48Z")
> [@voltmeter](#): > > , if its higher then the module is not my problem anymore 🙃 It’s there to avoid spikes, electrostatic discharge etc. If you are going to the hassle of unsoldering it, you may as well just flip it over and solder it back on. Its quite a large part, so not difficult to solder. ---
**Author:** ![stuart](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/stuart/32/16661_2.png) [@stuart](https://community.openenergymonitor.org/u/stuart)\ **Post date:** [16 March 2021 14:03 UTC](https://community.openenergymonitor.org/t/warning-jlcpcb-module-v4-40-and-part-d2/17176/13 "2021-03-16T14:03:05Z")
Just did a bit of research, these parts are meant to be similar, all marked SMBJ5.0A, all the same size/footprint (D\_SMB) however when placed via JLC, the + and - is flipped! ```auto C10204 + on right C294856 + on right C113974 + on right C357965 - on right C473804 - on right ``` I’ve just updated the PCB silkscreen to assist with a “stripe” marker. ![image](https://community.openenergymonitor.org/uploads/default/original/3X/8/0/80d63d3945935b5e21e98fcac27bfb292c3c5523.jpeg) ---
**Author:** ![Fred7421](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/fred7421/32/17293_2.png) [@Fred7421](https://community.openenergymonitor.org/u/Fred7421)\ **Post date:** [16 March 2021 19:26 UTC](https://community.openenergymonitor.org/t/warning-jlcpcb-module-v4-40-and-part-d2/17176/14 "2021-03-16T19:26:20Z")
I use marks like this, it helps me place diodes leaving no doubt. ![DIODEMARKER](https://community.openenergymonitor.org/uploads/default/original/3X/5/2/52ebe56dd88dfecb611224a82fe4f0845da7548d.jpeg) ---
**Author:** ![stuart](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/stuart/32/16661_2.png) [@stuart](https://community.openenergymonitor.org/u/stuart)\ **Post date:** [16 March 2021 20:05 UTC](https://community.openenergymonitor.org/t/warning-jlcpcb-module-v4-40-and-part-d2/17176/15 "2021-03-16T20:05:26Z")
Good idea, is that a standard kicad footprint? ---
**Author:** ![Fred7421](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/fred7421/32/17293_2.png) [@Fred7421](https://community.openenergymonitor.org/u/Fred7421)\ **Post date:** [16 March 2021 20:56 UTC](https://community.openenergymonitor.org/t/warning-jlcpcb-module-v4-40-and-part-d2/17176/16 "2021-03-16T20:56:41Z")
No I just made it up I guess it could be made into a couple of footprints (left and a right) > [@stuart](#): > > is that a standard kicad footprint? ---
**Author:** ![atanisoft](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/atanisoft/32/14690_2.png) [@atanisoft](https://community.openenergymonitor.org/u/atanisoft)\ **Post date:** [16 March 2021 21:23 UTC](https://community.openenergymonitor.org/t/warning-jlcpcb-module-v4-40-and-part-d2/17176/17 "2021-03-16T21:23:52Z")
Some boards use a “K” to indicate the cathode end of the diode… There are a few options for this likely. ---
**Author:** ![Fred7421](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/fred7421/32/17293_2.png) [@Fred7421](https://community.openenergymonitor.org/u/Fred7421)\ **Post date:** [16 March 2021 21:35 UTC](https://community.openenergymonitor.org/t/warning-jlcpcb-module-v4-40-and-part-d2/17176/18 "2021-03-16T21:35:54Z")
I feel like there are letters all over the silkscreen. I’ve also tried pluses and little arrows, they weren’t as clear for me. Also that leaves some space if I wanted to say what color the led was/is. ![DIODEMARKER-2](https://community.openenergymonitor.org/uploads/default/original/3X/9/0/90e2d6afc11cc7cb7a765c81a25c7451d7bf262a.jpeg) ---
**Author:** ![Fred7421](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/fred7421/32/17293_2.png) [@Fred7421](https://community.openenergymonitor.org/u/Fred7421)\ **Post date:** [16 March 2021 21:50 UTC](https://community.openenergymonitor.org/t/warning-jlcpcb-module-v4-40-and-part-d2/17176/19 "2021-03-16T21:50:29Z")
If you are wondering, I’m making the new controller board easier for me to assemble and use. It’s still in progress though. I’ve moved the vias that were directly on top of a pad and gave some tracks a little breathing room along with changing the jst-ph connectors. ![CONTROLLERV2-EASY](https://community.openenergymonitor.org/uploads/default/original/3X/d/e/ded850b0adf611489680c11de7ee3de061a4da03.jpeg) ---
**Author:** ![voltmeter](https://community.openenergymonitor.org/letter_avatar_proxy/v4/letter/v/9de053/32.png) [@voltmeter](https://community.openenergymonitor.org/u/voltmeter)\ **Post date:** [17 March 2021 02:27 UTC](https://community.openenergymonitor.org/t/warning-jlcpcb-module-v4-40-and-part-d2/17176/20 "2021-03-17T02:27:26Z")
not difficult to solder yes on a new pcb managed to unsolder only with two soldering irons heating both ends of D2 then rotate it and it wont lay flat on the solder joints because of old solder, so again two irons left and right and then it was in place was very funny 🙂 but now all modules D2 is stripe on the + marking of the board waiting for the attinys and the new controller to complete the built thanks for your help and your work for that great bms. [Next page](https://community.openenergymonitor.org/t/warning-jlcpcb-module-v4-40-and-part-d2/17176.md?page=2)