Hi,
I have a couple of cases where transistors are getting a bit too hot. I read in another thread with a similar title that from 60 to 70 C is not good; but that it all depends on each transistor's specifications.
The first case I have doubts about is my second hand analog oscilloscope. The intensity of the trace always gave me some problems in terms of brightness. 6 months ago I cleaned a potentiometer inside that regulates the intensity, and I got it back normal (thanks MrChips for the help). However, now it began to fail again and adjusting the pot has no effect. I noticed that the whole area of the circuit that deals with the intensity looks darker than the rest -as if it was slowly burnt-. I measured the temperature of the three transistors in that area with an infrared thermometer and I get a minimum of 65 C in just a minute after turning it on. Would this be normal?
Here is a picture of the circuit. It's the 3 transistors on the top-right corner:
Thanks in advance for your help.
...
Edit: removed the second case concerning the power supply
I have a couple of cases where transistors are getting a bit too hot. I read in another thread with a similar title that from 60 to 70 C is not good; but that it all depends on each transistor's specifications.
The first case I have doubts about is my second hand analog oscilloscope. The intensity of the trace always gave me some problems in terms of brightness. 6 months ago I cleaned a potentiometer inside that regulates the intensity, and I got it back normal (thanks MrChips for the help). However, now it began to fail again and adjusting the pot has no effect. I noticed that the whole area of the circuit that deals with the intensity looks darker than the rest -as if it was slowly burnt-. I measured the temperature of the three transistors in that area with an infrared thermometer and I get a minimum of 65 C in just a minute after turning it on. Would this be normal?
Here is a picture of the circuit. It's the 3 transistors on the top-right corner:
Thanks in advance for your help.
...
Edit: removed the second case concerning the power supply
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