A friend asked me to fix his Technics SA-300 because it had a noisy volume pot as well as some noisy switches. I injected some contact cleaner into the relevant spots and successfully tested it into a small test speaker. however, some of my switching testing must have been at too high a level as I have blown the amp on the channel that I had connected to the speaker and the output fuse blew but not before the speaker coil was burned out and (with a new fuse) there is full power supply DC across the output terminals of that channel (other is OK). I see that the output modules (STK0039) are available online but before doing a replacement I want to check voltages to make sure that the replacement is not also going to fry. I want to check particularly that there is no DC getting into the input of the amplifier module (in case there is an underlying fault).
Can anybody point me to a good source of a schematic that covers at least the power supply and the output stages?
Can anybody point me to a good source of a schematic that covers at least the power supply and the output stages?
The stks available online are all fake and will fry easily or immediately. If your originals are blown you're sadly SOL. No fixing this one.
I, in my ignorance, find this hard to believe. Sure, there may be some rogues in the cyber marketplace, but why would the larger sellers want to risk their reputations by selling known fakes? and why would anybody go to the trouble of making fake versions of such specialised items?
So to help me, can any members of this forum relate their experiences in buying these (or similar hybrid modules), positive or negative?
Your and others ignorance is why these things keep getting sold. When you later fail you will attribute the failure to your own inexperience. This happens every time, people never learn.
If you have a specific experience please relate it. Specifics, I think everyone around the world is getting tired of hand-waving and generalities. Hint at the seller if you like, or not. But we need to know what happened, which chips, so if we have to, we can look for substitutes(like the little sansui which was fixed with surplus higher-rated chips,only two pins had been relocated).
- Status
- Not open for further replies.