Signal Relay Bad

needforspeed

The Spin Doctor
Subscriber
I have a Musical Fidelity Phono Pre amp, And it started a loud clicking. Opened it up, And one corner of the board gets very hot, And feel 2 relays vibrating more than the others. I found the relay on line, But a 20 week wait? There is a Panasonic hat I think is the substitute, But will that change the sound? Thanks in advance
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From what you describe it sounds like whatever drives the relay is suspect. A bad relay shouldn't cause heat issues.

Is the power supply ok? Correct voltages, no ripple? That's where I'd start looking.
 
Likely a relay driver pass transistor. Or regulated supply pass transistors. Are there heatsink mounted transistors on that corner of the board ?

Thanks for reply, I have a pic. I pulled one reply that felt hot. Also, These are stick on, My first time with that style
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The lower left corner got very hot
 
From what you describe it sounds like whatever drives the relay is suspect. A bad relay shouldn't cause heat issues.

Is the power supply ok? Correct voltages, no ripple? That's where I'd start looking.

I use an external power supply, Pangea P-100. Seems okay
 
The external power supply may feed an internal power network, and if it's getting hot in that corner that may be the issue.

As avionics pointed out SMT is a pain to work with. But it is doable if you have good tools and are careful.

Check for shorts around where it's getting hot.
 
sounds more like the relay is being fed too much voltage, or its getting AC when it should be getting DC. Either way I'd agree that its probably not the relay so much as whatever controls it.


Put the power supply on the scope, thats really the only way to tell if it has ripple problems.
 
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