AussiePete
pfm Member
Hi,
I have recently built another couple of SKA GB150 amp modules and have a weird issue with one.
I need to say that this board was working perfectly until the power ground wire released itself from the power supply (GB300S), which caused it to blow a test resistor wired into the F2 fuse holder.
I replaced that and everything was good; it biased up to the 1.2V I usually run it at, and let this burn in for a couple of days and connected a speaker, only to have the test resistors blow.
I changed these again and they blew on switch on.
It will boot up without issues without a speaker attached but, with speaker attached it will only boot up if I turn the bias right off and then turn it back up to the normal 1.2V without issues or any burning.
It plays sweet music (although just fired up with my Iphone and cheap TV speakers), runs cool and apparently perfect.
I noticed today that the resistor across F1 (+ rail) was at 1.14V and the one across F2 (- rail) had 1.31V across it.
The other side module was even on both sides, and they both run cool to the touch and even temperature.
I believe the schematic is available, if not, I'll open a flicker account seeing as I've locked myself out of photobucket.
Can anyone shed any light on what might be causing this?
Thanks,
Pete
I have recently built another couple of SKA GB150 amp modules and have a weird issue with one.
I need to say that this board was working perfectly until the power ground wire released itself from the power supply (GB300S), which caused it to blow a test resistor wired into the F2 fuse holder.
I replaced that and everything was good; it biased up to the 1.2V I usually run it at, and let this burn in for a couple of days and connected a speaker, only to have the test resistors blow.
I changed these again and they blew on switch on.
It will boot up without issues without a speaker attached but, with speaker attached it will only boot up if I turn the bias right off and then turn it back up to the normal 1.2V without issues or any burning.
It plays sweet music (although just fired up with my Iphone and cheap TV speakers), runs cool and apparently perfect.
I noticed today that the resistor across F1 (+ rail) was at 1.14V and the one across F2 (- rail) had 1.31V across it.
The other side module was even on both sides, and they both run cool to the touch and even temperature.
I believe the schematic is available, if not, I'll open a flicker account seeing as I've locked myself out of photobucket.
Can anyone shed any light on what might be causing this?
Thanks,
Pete