• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Technics SU-8022 left channel gone dead

T

tobimai

New Member
Hello

I have an old Technics SU-8022 Amplifier, and a few days ago I was testing some speakers with it, but the protection fuses were blowing all the time. Now I figured out that this was caused by the speaker, I don't know why, it has 4Ohms (3,5 with my cheap multimeter) which is OK for this device. Now I got some new Fueses and discovered that left Channel stopped working, but I have no idea why. I checked all the obvious connections with my multimeter, but everything was fine ( like speaker switch to amplifier chip...). This device has two big chips(do I call them cips) in it, one says "STK0039N", which is the amplifier, and the other one says "Darlington Power Pack" with a small text under it which ends with 0059, you can't read it anymore. I also checled for blown capacitors. I hope someone can help me.
 
Register to hide this ad
This thread is dead and the OP never posted here since April 2016.
What you don't want to do is up-rate the fuses so they don't blow. That would ensure damage to the STK modules, if they are not blown already.

One possible cause can be bad / broken solder joints. These output packs are large and usually found in lower cost amplifiers where chasis stiffness is not great.

Then one can inspect / troubleshoot the chips by measurements but that requires knowledge on how to operate on AC powered equipment while plugged in. Better to have an isolation transformer to power them.
 
Yes... I know this little amp... It is not a very high rated amp but a nice daily speaker driver...
SaSi is right... check the soldering side and resolder the STK.... DO Never ever Replace the fuse with high amp value... sure way to kill the STK...

If you speaker read 3.5 Ohms dc on a multimeter It is sure to say that In AC (music) conditions this speaker goes far below 3 Ohms.. That little STK does not like for a long time..

My gues is you have blown the STK ... They are not that expencive anymore...something between €13,-- and € 35,--
 
You must log in or register to reply here.
Back
Top Bottom