Hypex DS1.2 broken
 

Well, somehow my Hypex DS1.2 lost almost all of its voltage gain.. I started to wonder why I don't hear the subwoofer anymore, and eventually I checked out the output with a oscilloscope (I used an 8 ohm load), and I noticed that the output was only slightly higher than input when the volume potentiometer was turned to max! The first thing that came into my mind was that maybe some op amps had blown up, and I didn't find any reasonably sized output from the first IC where the signal from the input seems to go..

Any ideas?

I know this is an old thread but, did you ever figure this out? This happened to me today after I stupidly shorted the two speaker terminals together. There also seems to be some surface damage on one of the chips (R050). I'll take photos when I have the time (will be away for a fortnight).

Some time ago I also had a broken UcD180 (quite similar to the DS1.2). You can find a schematic of its predecessor if you google for UM101555 (formerly Philips, now NXP). I could get the device back to life by exchanging the burnt 0.05 Ohm resistor and the power MOSFETs (some IRF640 will do as well if you cannot get the original PHP18NQ11T).

Good luck!
Hans