relay control problem

[HackoBoy]

Hello
There is no one to help in my town.
I have a demo stand for car players and speakers.
After it turns on and works after hours or minutes - it blocks.
There are several boards mounted in the rear end and with the help of non-retentive buttons I select a player and a speaker. The indication works as well as the relays.
After it freezes - nothing works and the only option is to turn it off and on.
Sometimes when turning on USB memory, or as the selected player plays.

 

[HarryA1]

It is difficult to help you with no circuit diagram or photographys. Such problems are often thermal in nature. Something supplying current to the relay over heats and shut down perhaps. 

"Sometimes when turning on USB memory, or as the selected player plays. " Does that block it or unblock it?

 

[HackoBoy]

blocked. Sometimes everything works, but sometimes it crashes.

Is it possible that the power supply unit has problems and interferes with the control.

 

[HarryA1]

 You could check the voltage output of the power supply before and after you have a problem with the  unit. That would tell you if it is the power supply or not.

 

[HackoBoy]

I found the problem quite by accident
When the problem came, I measured the voltage of the lm7812 - input and output = 0 volts.
I started measuring with a multimeter and pushed the electrolytic capacitors and other elements - and when I pushed the fuse housing that is mounted on the circuit board - the test started.

It turned out to be a bad solder, and during the vibrations from the low-frequency speakers - it breaks.
I will resolder the fuse contacts tomorrow.

 

[paulbellows]

Hey! I understand it's tough when there's no local help available. To troubleshoot the freezing issue with your demo stand for car players and speakers, try these steps:
Check for loose connections.
Ensure proper ventilation to prevent overheating.
Look for firmware/software updates for the boards or players.
Test different players and speakers to identify any specific issues.
Seek remote assistance from technical support or online forums.
Finally, if the problem is not solved, consider calling a technician for further help.