I have fun posting these, I always hope someone can learn along with me, and maybe geta kick out of seeing these old radios come back to life.
Here's another Sears Roadtalker, it's a 663.38070700 AM Radio. I had recently pulled a few radios off the shelf to make sure they work to put on marketplace.
Check out the video, It describes the issue best.
This happens any time the power is cycled, all of the electrolytics in the audio area have been replaced, the audio is always there at pin 4, but not on pin 10, and behaved the same way with C109 removed, so it must be localized within the 1156 audio chip. Pin 1 always had it's voltage and pin 8 is always had it's ground. The 1156 was swapped out with a known good chip this morning, but the issue remains.
I won't be able to peek at this again until Sunday.
The only thing I can think of is my using a 100uf in C105s spot instead of the original 33uf to help plump up the bottom of the amplified audio...... Thinking, this is a long output delay, a way larger cap would cause.....
As you can see after everything catches up, everything looks and sounds great...
Thanks for having a peek, here's the related SAMs and my favorite part *the video*.... Enjoy!
EDIT: I forgot to mention that the PA speaker output had the same issue.
Here's another Sears Roadtalker, it's a 663.38070700 AM Radio. I had recently pulled a few radios off the shelf to make sure they work to put on marketplace.
Check out the video, It describes the issue best.
This happens any time the power is cycled, all of the electrolytics in the audio area have been replaced, the audio is always there at pin 4, but not on pin 10, and behaved the same way with C109 removed, so it must be localized within the 1156 audio chip. Pin 1 always had it's voltage and pin 8 is always had it's ground. The 1156 was swapped out with a known good chip this morning, but the issue remains.
I won't be able to peek at this again until Sunday.
The only thing I can think of is my using a 100uf in C105s spot instead of the original 33uf to help plump up the bottom of the amplified audio...... Thinking, this is a long output delay, a way larger cap would cause.....
As you can see after everything catches up, everything looks and sounds great...
Thanks for having a peek, here's the related SAMs and my favorite part *the video*.... Enjoy!
EDIT: I forgot to mention that the PA speaker output had the same issue.
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