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Beomaster 6000 Power-On Issue
71 replies
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Exactly. Mine has the same mark/cut. Part of the modification, I guess.
In other news, after replacing R89 again, I was able to get around 2.3V across R95. Did not solve my issue, however, as the 6000 still won't fire up beyond colon and standby dot on the display.
In other news, after replacing R89 again, I was able to get around 2.3V across R95. Did not solve my issue, however, as the 6000 still won't fire up beyond colon and standby dot on the display.
The signal coming in on pin38 shouldn't make any difference for the BM6000 starting up. It is related to the FM frequency display.
Does the voltage across R95 change when you adjust R89?
Glitch
Does the voltage across R95 change when you adjust R89?
Glitch
It does now, yes.
What about Pin16 on the cpu (the 50/60Hz signal)? This signal comes from TR4 on the power supply board # 16. I'm not getting a square wave from the collector of TR4, but I might not be measuring correctly. Is this signal required for CPU startup?
From the schematic, it looks like the CPU supplies the +5v for the 50/60 Hz signal (likely via a pull-up resistor on pin16). 16TR4 then pulls down pin16 in sync with the line voltage. Not seeing a signal could be that the CPU is not supplying the voltage to pin16 or that 16TR4 or 16D5 is bad.
What happens on pin16 when you power-up?
My best guess is that the 50/60Hz signal would NOT be needed to initialize. The only thing that I could think of it being used for is for the timer functions (which aren't critical for operation). Then again, there could be a few lines of code that check for the signal changing and fault the processor if it isn't as expected. I would expect the display to indicate a fault if this happened.
What is insidious about trying to debug this are the possible "chicken or the egg" situations that could be happening and not knowing if one is dealing with chickens or eggs ;-).
What does you display do when you power up?
Glitch
What happens on pin16 when you power-up?
My best guess is that the 50/60Hz signal would NOT be needed to initialize. The only thing that I could think of it being used for is for the timer functions (which aren't critical for operation). Then again, there could be a few lines of code that check for the signal changing and fault the processor if it isn't as expected. I would expect the display to indicate a fault if this happened.
What is insidious about trying to debug this are the possible "chicken or the egg" situations that could be happening and not knowing if one is dealing with chickens or eggs ;-).
What does you display do when you power up?
Glitch
Ok, thanks. I guess i was following it backwards.
My machine does not power up. When plugged in I only get the standby light and clock colon. The radio LEDs glow and volume motor spins endlessly too (despite pot position). Nothing happens beyond that. Buttons do nothing.
My machine does not power up. When plugged in I only get the standby light and clock colon. The radio LEDs glow and volume motor spins endlessly too (despite pot position). Nothing happens beyond that. Buttons do nothing.
The signal on pin 16 is definitely required for a normal startup.I disagree, at least for my BM6000. Here is a picture of the the receiver running with pin P42-1 on board 16 disconnected (i.e. the 50/60 Hz signal). Login to view image The BM6000 does have some power drop protection, but it is implemented as part of the RESET circuit. Glitch
Hi
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