jcon109
Active Member
I have a HK 330b that I loaned out to someone. When it was returned the person told me it quit working.
After some testing I discovered the 4 output transistor were bad. (2sc1107). I also tested the driver and predriver transistors and they tested good. A conducted a good visual inspection and nothing else looked burnt or damaged. Replaced the outputs with 4 TIP41c and fired it up with a dim bulb tester. Everything worked and sounded great with 15 watt, 40 watt, 60 watt then 100 watt bulbs. I thought I was safe. I then tried it plugged into the wall and it blew all 4 output transistors (actually blew two of them into pieces, one on each channel)
Any thoughts on where to look?
Thanks.
After some testing I discovered the 4 output transistor were bad. (2sc1107). I also tested the driver and predriver transistors and they tested good. A conducted a good visual inspection and nothing else looked burnt or damaged. Replaced the outputs with 4 TIP41c and fired it up with a dim bulb tester. Everything worked and sounded great with 15 watt, 40 watt, 60 watt then 100 watt bulbs. I thought I was safe. I then tried it plugged into the wall and it blew all 4 output transistors (actually blew two of them into pieces, one on each channel)
Any thoughts on where to look?
Thanks.