Re: Sudden failure in early life

Alan G4ZFQ

Nothing or two rows of blocks depending on the pot position.
If you read the troubleshooter it gives you instructions on what to do next.
What firmware?

I went down the whole list of voltage checks.
As you are concerned with the micro these are not required at the moment. Although micro voltages might be.

73 Alan G4ZFQ

Lots_ of problems, so
maybe you can figure out where I should be looking. I'll only list the significant voltage discrepancies:
Clk0 and Clk1 test pins - no squarewave, no DC
Top side of C43 0.95v
Top sides of C44, C45, C46 all 1.31v
_IC5 pin 1, pin 2_  1.31v, _pin3_  0.86v, _pin5 _0.87v, _pins 6,7_  1.32v
_IC6 pins 1,2,3,5,6,7_ all 1.37v
_IC7 pins 1,2,3,5,6,7_ all 1.37v
_IC8 pins 1,2,3,5,6,7_ all 1.38-1.40v
_IC9 pin 3_  5.9v, _pin 5_  1.38v, _pins 6,7_  1.41v
_IC10 pins 5,6_  5.9v
_LCD pin4 1.21v_, _pins 7,8,9,10,11_  5v_,_ _pins 12, __13_ 0v.
I hope this provides plenty of clues.
On 3/17/2018 12:06 AM, Alan G4ZFQ wrote:
correct voltage at the R1-R2 divider, so I probably had grounded it.


Yes, maybe, just keep an eye on it as you progress.
I checked all the connections. Contrast
voltage range is correct. The 20 MHz oscillator is going strong. Is it
just possible that the microprocessor gave up the ghost while I was

Probably unlikely, bit just about possible. More likely joints, shorts.
Do all the checks in the LCD section show no errors?

73 Alan G4ZFQ

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