SANSUI AU-D55X protection Light

It's almost certainly normal for this amplifier. I own Lux and Parasound amplifiers that behave the same way.

It takes several seconds for the amplifier's voltages to stabilize at turn-on. The protection circuit leaves the speakers disconnected during this period. It then checks to see whether there's a DC offset at the output (and possibly at other points). If there is not, the speakers are connected.

Be grateful that the amp and the protection circuit are working correctly.

Bad caps in the supply.. The protection circuit is most likely detecting excessive ripple..

Also the I've found bad caps in the protection circuit itself..

A warm up tends to make some caps perform better. At some point, it'll get worse. Also, you may want to check for bad joints.

Though it's possible there /is/ something wrong with the protection circuit, five seconds is not an unreasonable delay. If the amp sounds okay, and works correctly... why go poking around?

I remember owning an Sansui amplifier that did the same thing. At power on the protection light turned on for 5 - 6 seconds, then it turned off and the amplifier started to operate. It did that since new, so that=B4s the way the protection ciruit was designed to operate. I think the user manual said the same.

I had a Sansui amplifier years back with the same protection circuit and it did the same thing, it looks for a short across the speaker terminals after you switch on, if all ok the light goes off.

Most protection circuits wait a few seconds for voltages to equalize and then allow the speakers to be connected to the amplifier. I would say the

OK, friends most of your advices and comments reinforce my idea that there is really nothing wrong with my amplifier. In the meantime I checked as a precaution the DC-offset at the speaker terminals and the Bias setting driving the Main. All measurements indicated no anomalies, so I guess it is safe to state that a blinking PROTECTION light at start-up of my Sansui AU- D55X is a NORMAL indication provided the speaker relay is activated in ~~5 seconds...

So..If it ain't broken, I cannot fix it....

TY Brasto

I used to do Sansui warranty and found their equipment very sensitive regarding self testing designs. Meaning that the slightest little problem kept any protection circuit active. I was always given the tough-dog Sansui units since nobody else had the patience, dedication and experience to repair them.