Power supply VIN MKR1400

Goodmorning everyone
can someone help me?
I am using an MKR1400 for my project, the problem is that by powering the card via VIN with a 5 Volt and 5A power supply, the card connects for about 30 seconds, then the connection drops, and reconnects only if I reset, how can I do you solve? is it possible that there is a problem with the card?

Are you using a battery in addition to the 5 V power supply? If not, I think the answer is given here:

depending on how strong is your signal and if you're on 2G or 3G you may want to check R28, connected to ILIM pin of the BQ24195. the current resistor is 330 ohm and limits current from USB to 1.6A. since there's a DC-DC converter that steps down from 5v to 3.8V, the max current to the modem would be around 2A to which you would have to subtract the current going to the rest of the board.
if your application requires more current (if you use 2G it's likely to be more) you should change that resistor to prevent current limit and this will also allow you to get rid of the battery. from BQ24195 data sheet current limit is set to ILIM=530/R28.

So, even though your power supply is rated for plenty enough current, the power circuitry on the MKR GSM 1400 is such that, depending on the usage, the GSM radio might still not get enough power to sustain it through the short spikes of high current draw while communicating.

If you don't want to replace the resistor, you might be able to solve the problem by connecting a LiPo battery with a good capacity.

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no I don't use any battery, I have a power supply that is used for 5v 10A led strips, but it doesn't work.

good morning I discovered a section in Italian that I didn't know existed, since I know very little English and with google trasletor it's not easy, I apologize to everyone and thank you I propose the question on the forum in Italian. thanks and good continuation