PastTechFan
Super Member
Well, my Dad's HK730 crapped out in mid-song last week. I think I've narrowed it to the preamp section (no signal out to another amp), but the amp section (when fed from another pre) only seems to have one channel. (I've forgotten which, but could check if that helps.)
I checked all the fuses, and found the two 2.5 amp ones beside the rear transformer were blown. (Upper left in pic below.) I replaced those, and hooked it up to my (newly built) dim bulb tester. I used a 75 watt bulb, and got a strange result. The bulb glowed, then dimmed, then after about 5 seconds, began to glow again. After a few more seconds, I shut it down. So, I understand that the glow means a short, but why would the bulb dim, then glow again? The short is maybe not present until a cap(s) charges?
Beyond Deoxit, I have no idea what I'm doing under the hood. Anyone care to offer thoughts? Something obvious I should dig into?
I checked all the fuses, and found the two 2.5 amp ones beside the rear transformer were blown. (Upper left in pic below.) I replaced those, and hooked it up to my (newly built) dim bulb tester. I used a 75 watt bulb, and got a strange result. The bulb glowed, then dimmed, then after about 5 seconds, began to glow again. After a few more seconds, I shut it down. So, I understand that the glow means a short, but why would the bulb dim, then glow again? The short is maybe not present until a cap(s) charges?
Beyond Deoxit, I have no idea what I'm doing under the hood. Anyone care to offer thoughts? Something obvious I should dig into?
