# WP7702 and MangOH Red Power Supply **URL:** \ **Category:** mangOH Red\ **Created:** [March 23, 2018, 10:32am UTC](https://mangoh.discourse.group/t/wp7702-and-mangoh-red-power-supply/1270 "2018-03-23T10:32:07Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![ivand](https://avatars.discourse-cdn.com/v4/letter/i/8dc957/32.png) [@ivand](https://mangoh.discourse.group/u/ivand)\ **Post date:** [March 23, 2018, 10:32am UTC](https://mangoh.discourse.group/t/wp7702-and-mangoh-red-power-supply/1270/1 "2018-03-23T10:32:07Z")
Hi all, the main issue working with mangOH red and the WP77 is mangOH red is not able to supply correctly the WP77 because mangOH red uses the power supply from the USB (even USB 3.0). My Sierra Contact recommended me power the mangOH red with an external power supply and now works perfectly! I suppose mangOH green doesn´t have this problem because is powered from other than USB. Please, if you are using WP77 and mangOH red take this into account. ---
**Author:** ![asyal](https://sea2.discourse-cdn.com/flex016/user_avatar/mangoh.discourse.group/asyal/32/78_2.png) [@asyal](https://mangoh.discourse.group/u/asyal)\ **Post date:** [March 23, 2018, 12:23pm UTC](https://mangoh.discourse.group/t/wp7702-and-mangoh-red-power-supply/1270/2 "2018-03-23T12:23:44Z")
The mangoh red plus wp77 works using USB input. Just make sure your computer USB can provide enough power. Ashish ---
**Author:** ![ivand](https://avatars.discourse-cdn.com/v4/letter/i/8dc957/32.png) [@ivand](https://mangoh.discourse.group/u/ivand)\ **Post date:** [March 23, 2018, 12:34pm UTC](https://mangoh.discourse.group/t/wp7702-and-mangoh-red-power-supply/1270/3 "2018-03-23T12:34:29Z")
I´ve tested with USB 3.0 (1Amp), and doesn’t work. My mangOH red is REV5. ---
**Author:** ![asyal](https://sea2.discourse-cdn.com/flex016/user_avatar/mangoh.discourse.group/asyal/32/78_2.png) [@asyal](https://mangoh.discourse.group/u/asyal)\ **Post date:** [March 23, 2018, 12:59pm UTC](https://mangoh.discourse.group/t/wp7702-and-mangoh-red-power-supply/1270/4 "2018-03-23T12:59:16Z")
Doesn’t power up or doesn’t transmit? Can you show your setup ---
**Author:** ![ivand](https://avatars.discourse-cdn.com/v4/letter/i/8dc957/32.png) [@ivand](https://mangoh.discourse.group/u/ivand)\ **Post date:** [March 23, 2018, 1:11pm UTC](https://mangoh.discourse.group/t/wp7702-and-mangoh-red-power-supply/1270/5 "2018-03-23T13:11:26Z")
Whenever WP77 try to fallback from LTE to GSM band, always restarts the board. Could you test this behaviour?? ---
**Author:** ![asyal](https://sea2.discourse-cdn.com/flex016/user_avatar/mangoh.discourse.group/asyal/32/78_2.png) [@asyal](https://mangoh.discourse.group/u/asyal)\ **Post date:** [March 23, 2018, 1:13pm UTC](https://mangoh.discourse.group/t/wp7702-and-mangoh-red-power-supply/1270/6 "2018-03-23T13:13:25Z")
That might be due to inability of USB power supply on your computer to provide the necessary burst current. So yes in that case use a USB connected wall adapter. ---
**Author:** ![davidc](https://avatars.discourse-cdn.com/v4/letter/d/a183cd/32.png) [@davidc](https://mangoh.discourse.group/u/davidc)\ **Post date:** [March 26, 2018, 4:58am UTC](https://mangoh.discourse.group/t/wp7702-and-mangoh-red-power-supply/1270/7 "2018-03-26T04:58:33Z")
Hiya, Power supply requirements (current and rise time) for GSM are significantly different for GSM and LTE. Table 3.3 in the WP77 PTS indicates that typical supply current for LTE is 800mA and for GSM is 1.0A, and the Max current for LTE is 1.5A and for GSM is **3.0A** I have also had modules ‘black-banned’ from the network because they were not meeting transmission standards - in my case it was **always** an issue with the power supply not being able to meet the TX specs. ciao, Dave