sim7090G does not want to start

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fanfan69

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hello, I bought 6 sim7090g modules, the six do not want to start, I specify that I bought them on alixepress from three different suppliers, using PWRKEY nothing happens on the pin we have a voltage of 1.7 volts
 

Hi,

not much information we can validate or work with.

So my recommendation:
* read the datasheet carefully
* follow the datasheet rules and requirements
* I´d say there is more than 90% chance that they will work .. when treating them properly-

Klaus
 

You must temporarily connect the PWRKEY pin to GND to power up the module.
 

thank you for your answers, I set PWRKEY to GND but no response, here is a simplified diagram of my PCB
 

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Hi,

I never use this module ...

but it has a power supply pin named with VBAT. Obviously the abbreviation for "battery voltage".
My I ask why you did not connect it to your battery?

Klaus
 

Also what does "...do not want to start..." mean?
What tests have you done?
What does work as you expect and what doesn't - and for the last part what do you expect and what do you get?
Applying proper testing processes and describing them clearly will help everyone understand what is happening.
Susan
 

thank you for your answers, hello KlausST, the battery is correctly connected the Vbat is a netflag which powers another component on the PCB, hello Aussie Susan, I mean that nothing happens when powering up even with the PWRKEY, the status LED does not light up, the module does not respond to any AT command, I am sure that it is powered because I have the right voltage on the PWRKEY.
 

There is no "right voltage" for the PWRKEY pin. It must be pulsed to GND for switching the module on/off.
First, let the VBAT voltage rise and stabilize with the PWRKEY pin disconnected.
To power up/down, connect the PWRKEY pin to GND for about 2 seconds, then disconnect the pin again.
 

I know that I read the entire technical sheet and there is good voltage on PWRKEY here is an extract from the sheet
"The level is 1.5V when this
PIN is floating;
PWRKEY should never be
pulled down to GND
permanently."
 

Hi,

I fully agree with std_match.

Please give useful and complete informations.

aliarifat794 said:
Please check if your power supply is sufficient.
Click to expand...
I can only repeat. --> use a scope to show the power supply pin voltage.

fanfan69 said:
on the pin we have a voltage of 1.7 volts
Click to expand...
on which pin?

fanfan69 said:
here is a simplified diagram of my PCB
Click to expand...
Why only simplified? We need to see the whole story. Show the full schematic

fanfan69 said:
my battery is 2600mah 3.8v and 9.88wh
Click to expand...
These all are theoretical / nominal values. But don´t tell what the SIM module sees.
The battery may be old, discharged, bad connection, ... we don´t know ... thus we asked you to check.

fanfan69 said:
the battery is correctly connected
Click to expand...
I don´t know what you call "correctly"
It still is not according the datasheet.

Also the datasheet tells: "the power supply capability must be up to 500mA." ..
How can you guarantee this while using a regulator specified for 250mA only?

fanfan69 said:
when powering up even with the PWRKEY
Click to expand...
What does "even with the POWERKEY" .. mean?


Here a half of information, there a half of information ... I guess it´s time for me to leave. Good luck

Klaus
 

you have all the information, 1) it's an LGA module so the pins are not visible, 2) the voltage is 1.5 volts on the PWRKEY pin and not 1.8 volts mea culpa but this means that the module is powered, 3 ) when I say with PWRKEY or without, that seems clear to me, right? has GND or not, the rest of the diagram is not active so it won't help, I'm not a beginner in this matter, looking down on me won't help anyone, the only thing I'm going to change is the regulator which in fact does not correspond as you noted. PS: I am not English so there may also be a translation problem.
 

1.5V on the disconnected PWRKEY pin means that you have applied VBAT, not that the module is switched on.
From the hardware design manual:
"SIM7090G can be powered on by briefly pulling the PWRKEY pin to ground."
 
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