My Technics sa-gx690 stereo reciever blows fuses?

Just having a look at a SA-GX690 for a good friend of mine. Found one of the big 4 diodes blown on the main board.
Replaced it. Display message shows overload, unable to get anything else working. I did notice a small transistor above the smaller filter caps had been hot at some stage as the board did discolour a bit. Can't find a replacement for that.

Raymond, New Zealand
December 2013

Well my 690 just joined the group. After 10+ years of excellent service, upon powering up last night, there came a sort of growling noise that lasted about 1/2 second, then nothing but the help/reset orange button lights up. Has anyone succesfully found a fix?

Sundowner
May 2009

Had the same thing happen to my 690 this week. Tracked the fault to one of the bridge diodes on the MAIN board not the PSU board (it was shorted). They are the 4 black large ones elevated above the board (3amp 200V)

George
January 2009

I have the same unit that's worked flawlessly for the past 10 years....until recently, that is. It seems after it runs for a few hours it gets "hot" and decides to cut off until it cools. Leave it alone, and it turns back on all by itself. This is simply a sign of old age and worn resistors, circuits, etc. Obviously, cleaning the inside to remove collected dust won't hurt, but it really won't fix the problem. Inevitably, we're going to have to bite the bullet and purchase a newer receiver.

J Baldridge
December 2008

I drive my 690 with a pair of Klipsch speakers. They are a highly reactive load. My amp gets VERY hot. I opened it up and cleaned the air passageway for the cooling system, took a toothbrush and also cleaned the blades of the fan. There was a LOT of dust buildup in there, and I can see why it went into protection mode once in a while.

BTW You can hold down the speaker A (or) B button for a second or two, and it will go into LOW IMPEDANCE mode. You will not be able to use both A + B speakers at the same time this way, but I found the amp to run cooler when I set it up this way. I can still run the surround modes in the low impedance mode too.

I hope this helped somewhat.

Jackie Krieg
May 2008

Well, Eric, wish I had an answer for you... exact same thing happened with my identical unit on 2008.03.13. Technics should be complimented on their planned obsolescence QC, image both of our units dying in the same timeframe.

Doesn't appear to be the power units, only blows when the two ribbon cables are plugged into the main board. Hopefully someone out there has a better answer, otherwise I will probably be buying something new... hate to see this go, like the fact it will drive 4ohm spks.

cheers/Brian

Brian
March 2008