Good morning,
I am about to replace the icepower 125 power amp module in my Gallien Krueger MB2-500 because it has been stuck in safety mode for ~6 months now! It has been this long for me to source a cheap enough replacement 125. Now, I checked the jumper from the AUX power-in on the icepower and traced it back to the GK preamp where it connects to. The transistor there looks, well, interesting. A little smokey in colour and some of the writing has gone. Here are some pic's.
A shot from the back:
Here's a front shot - sorry if the quality is bad - but its not much better in real life!
Here's a comparison with a nearby transistor, notice it's not as dusty:
So, could this transistor be dead? Is it possible to test without removing it from the board?
I am about to replace the icepower 125 power amp module in my Gallien Krueger MB2-500 because it has been stuck in safety mode for ~6 months now! It has been this long for me to source a cheap enough replacement 125. Now, I checked the jumper from the AUX power-in on the icepower and traced it back to the GK preamp where it connects to. The transistor there looks, well, interesting. A little smokey in colour and some of the writing has gone. Here are some pic's.
A shot from the back:
An externally hosted image should be here but it was not working when we last tested it.
Here's a front shot - sorry if the quality is bad - but its not much better in real life!
An externally hosted image should be here but it was not working when we last tested it.
Here's a comparison with a nearby transistor, notice it's not as dusty:
An externally hosted image should be here but it was not working when we last tested it.
So, could this transistor be dead? Is it possible to test without removing it from the board?