Sony home stereo randomly power cycles

buddyochoa · 07-22-2009, 10:01 AM

my sony stereo will randomly turn on and after a while turn back off. I dont know whats causing it. Is there anything that would interfere with it?

**octaneman** · 07-23-2009, 08:12 AM

Hi buddyochoa

Does your stereo have a timer ? If you are comfortable opening your stereo and do a little probing with a test meter then here's are some things to check. Some stereo's have a safety shutdown feature that prevents it from overheating to prevent components from being burned. The circuit is located on the power supply, it has a flame proof 2.2 ohm resistor. The resistor will get hot causing it to open, the power supply will then shut down cool off, and re-start again. Another thing to check are the capacitors, they are barrel like components that become bloated and misshapen when they are burned.

ebackhus · 07-29-2009, 07:16 PM

I like Octane's idea on the issue. The thermal trip protection is a very likely culprit based on what you're describing. My HT head unit gets VERY hot at times but I keep it isolated on a top shelf of a stand where it can be cooled easily. If it's surrounded by other components then the heat given off by them will also be a contributing factor.

I recall doing some cable work for someone and opened the cabinet where they kept their components. HOT LIKE HELL. No wonder they kept having problems...

buddyochoa · 07-30-2009, 05:33 AM

It ramdomly will turn on when its shut off. There no heat around it when its off

**octaneman** · 07-30-2009, 06:05 AM

The power supply still has to be checked to determine what type circuit is being used, either an opto-coupler or an oscillator switching type p/s.

07-22-2009, 10:01 AM	#1 (permalink)
buddyochoa Registered User Join Date: Jul 2009 Posts: 4 OS: Windows XP SP3	Sony home stereo randomly power cycles my sony stereo will randomly turn on and after a while turn back off. I dont know whats causing it. Is there anything that would interfere with it?

07-23-2009, 08:12 AM	#2 (permalink)
octaneman Mentor Home Support, Gearhead Automotive Center Join Date: May 2009 Posts: 541 OS: WINXP	Re: Sony home stereo randomly power cycles Hi buddyochoa Does your stereo have a timer ? If you are comfortable opening your stereo and do a little probing with a test meter then here's are some things to check. Some stereo's have a safety shutdown feature that prevents it from overheating to prevent components from being burned. The circuit is located on the power supply, it has a flame proof 2.2 ohm resistor. The resistor will get hot causing it to open, the power supply will then shut down cool off, and re-start again. Another thing to check are the capacitors, they are barrel like components that become bloated and misshapen when they are burned. Last edited by octaneman; 07-23-2009 at 08:14 AM.

07-29-2009, 07:16 PM	#3 (permalink)
ebackhus Manager, Design Join Date: Apr 2005 Location: SATX Posts: 14,223 OS: WinXP Pro SP3/Windows 7 RTM My System Blog Entries: 28	Re: Sony home stereo randomly power cycles I like Octane's idea on the issue. The thermal trip protection is a very likely culprit based on what you're describing. My HT head unit gets VERY hot at times but I keep it isolated on a top shelf of a stand where it can be cooled easily. If it's surrounded by other components then the heat given off by them will also be a contributing factor. I recall doing some cable work for someone and opened the cabinet where they kept their components. HOT LIKE HELL. No wonder they kept having problems... __________________ ----------------------------- There are no dumb questions, unless a customer is asking them. Help in the fight against cancer and other serious illnesses.

07-30-2009, 05:33 AM	#4 (permalink)
buddyochoa Registered User Join Date: Jul 2009 Posts: 4 OS: Windows XP SP3	Re: Sony home stereo randomly power cycles It ramdomly will turn on when its shut off. There no heat around it when its off

07-30-2009, 06:05 AM	#5 (permalink)
octaneman Mentor Home Support, Gearhead Automotive Center Join Date: May 2009 Posts: 541 OS: WINXP	Re: Sony home stereo randomly power cycles The power supply still has to be checked to determine what type circuit is being used, either an opto-coupler or an oscillator switching type p/s.