S5830 GPS problem

I have here a Lenovo tablet, a HTC Desire C, and an Ace S5830.
- Lenovo Tablet sees up to 11 - 12 GPS satellites.
- HTC Desire C, sees up to 7 - 8 GPS satellites
- Ace S5830 does not sees any GPS satellite.

To S5830 I made all possible changes that I have collected from XDA.
- I installed another firmaware with Odin.
- I replaced 4 times the modem.
- I changed numerous times gps.conf, and added to system/data/gps a file secgps.conf
- every time I set the continent and country with fastergps.apk

I believe I made all possible tests to S5830, but with no positive result.

My conclusion it is a hardware problem.
For example, Google Maps can locate me without GPS enabled, but with Internet connection active. So Google Maps does not require GPS for location, just for precision. But that's not my problem.

This phone was bought in 2011.
Until to me no one checked if the GPS works.
It was also several days in service, through 2014.

Anyway, I think it's a hardware problem.
Unfortunately.

The applications I use to search for GPS satellites are:
- GPS_Status_amp_Toolbox_4_1_1.apk
- GPS test plus.apk

For setting gps.conf I use:
- GPSfix-0.1.apk
- org.fastergps.apk
- PFGPS v2.0

Applications map I use:
- Google map
- MAPS.ME offline maps Pro v3.3
- OsmAnd-Maps-Navigation-2.1.1

Can anyone give me another solution, or explanation.

Thank you.