# ADH8066 Turns off after connecting

**URL:** <https://community.sparkfun.com/t/adh8066-turns-off-after-connecting/27187>\
**Category:** Wireless & IoT\
**Created:** [July 30, 2013, 11:30am UTC](https://community.sparkfun.com/t/adh8066-turns-off-after-connecting/27187 "2013-07-30T11:30:06Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![majodio](https://avatars.discourse-cdn.com/v4/letter/m/5daacb/32.png) [@majodio](https://community.sparkfun.com/u/majodio)\
**Post date:** [July 30, 2013, 11:30am UTC](https://community.sparkfun.com/t/adh8066-turns-off-after-connecting/27187/1 "2013-07-30T11:30:06Z")

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I have a ADH8066 GSM module ([https://www.sparkfun.com/products/10138](https://www.sparkfun.com/products/10138)) connected to the breakout board ([https://www.sparkfun.com/products/10497](https://www.sparkfun.com/products/10497)) and have followed the schematic ([http://dlnmh9ip6v2uc.cloudfront.net/dat … Update.pdf](http://dlnmh9ip6v2uc.cloudfront.net/datasheets/BreakoutBoards/ADH8066BreakoutBoardWiringCircuitUpdate.pdf)). I attached an oscilloscope to the GPIO3 and GPIO10 pins. When I pull the PWON pin low, I can see the GPIO10 pin go high for about 5-10 seconds and then the GPIO3 pin goes high for a split second and then both go low and stay that way.

Picture here: [http://sdrv.ms/1e3PY56](http://sdrv.ms/1e3PY56)

At first I figured it was a power issue, so I replaced the power supply with LT1529 voltage regulator ([http://cds.linear.com/docs/en/datasheet/1529fb.pdf](http://cds.linear.com/docs/en/datasheet/1529fb.pdf)) which is rated at 3A. I also added a 1000uF capacitor very close to the VBat terminal on the breakout board. Unfortunately, this didn’t help and I’m still seeing the exact same issue. I confirmed with the scope that the lowest voltage seen on the power lines was 3.6 volts, which according to the datasheet is sufficient. I have also connected the voltage regulator to a 350W ATX power supply and still get the same result.

My next thought was that the module was bad. I also have an evaluation board ([https://www.sparkfun.com/products/10741](https://www.sparkfun.com/products/10741)) so I plugged the module into that and it worked perfectly meaning that the module is fine. It’s apparently either a faulty breakout board, or I’m messing something up.

What steps should I take to continue troubleshooting this problem?

Thanks,

Matt

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**Author:** ![DaniP28](https://avatars.discourse-cdn.com/v4/letter/d/e0b2c6/32.png) [@DaniP28](https://community.sparkfun.com/u/DaniP28)\
**Post date:** [February 5, 2014, 4:31pm UTC](https://community.sparkfun.com/t/adh8066-turns-off-after-connecting/27187/2 "2014-02-05T16:31:50Z")

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Hi, I’m having the same problem with my module, I did pretty much the same you did and still can’t figure it out why keeps turning off, do you solve the problem? any suggestion?

Thanks

Dani

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**Author:** ![majodio](https://avatars.discourse-cdn.com/v4/letter/m/5daacb/32.png) [@majodio](https://community.sparkfun.com/u/majodio)\
**Post date:** [February 5, 2014, 5:23pm UTC](https://community.sparkfun.com/t/adh8066-turns-off-after-connecting/27187/3 "2014-02-05T17:23:26Z")

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I have not resolved the problem. I contacted Sparkfun support and they sent me a new board assuming that it was faulty. The new board had the same problem. They suggested that I connect it to a “Breakout Board for FT232RL USB to Serial” ([https://www.sparkfun.com/products/718](https://www.sparkfun.com/products/718)), but I haven’t actually had a chance to try that yet.

I noticed that Sparkfun stopped selling this breakout board, so I wonder if there was something wrong with the design?