I sent a reply to a bad address, oh well....

--

Clif Holland KA5IPF
www.avvid.com




"Gord S" wrote in message
...
I have the basic "instruction manual" and a schematic with RF adjustments
diagram......No service manual.

Problem - Unable to effect a reset of any kind. Radio "stuck" in current
configuration, and operational otherwise. Does not appear to be in lock
mode. Function button does not cause a change into function mode (no
menu's displayed etc).

Operationally - Radio works fine on previously programmed channels and is
stuck with the display in CHANNEL mode.
- Good tx output and waveform
- Good tx deviation
- Good receiver operation - DTMF operates
- Radio LCD display normal and shows channel change and s-meter bar graph
and whatever was programmed previously.
- Display does NOT show it's locked (no key symbol).

Observations - Front panel pushbuttons all cause a beep to be emitted when
pressed and a second beep to be emitted if held in for
approx 1.5 secs. Because the programmed channels work ok (DDS ok
assumed) and the push buttons all cause a beep to be emitted
(generated by the microprocessor IC201) , it would seem that that IC201 is
functioning. The inability to reset or cause a change into "Function"
mode (both with a particular change of display) leads me to wonder first
how it won't reset. I see IC209 (PST9130NR) labelled RESET and input to
the processor as RESET but I don't see any control to this other than
basic ON/OFF power. IC209 appears on the schematic to be basically a 3
terminal regulator with the output TP tagged at 4.7 vdc.......I measure
4.8 vdc (likely ok). Is this some sort of power up buffer or delay?

Checking pins of IC201, with the radio operational, appears daunting due
to it's location underneath the hard wired LCD.

Has anyone had a similar troubleshooting experience with this radio OR
knowledge of how the RESET works OR what might be locking the
microprocessor IC201? Might the EEPROM IC210 (X25160S1-2.7) be locking
IC201 (thinking about why the processor won't reset here.......perhaps the
EEPROM is disabling the micropro somehow?).

At this point, short of finding a problem with the RESET circuit (once I
know how that works), it would appear that replacing the front panel
module would be the only recourse.

Any constructive suggestions welcomed.


Gord - VE1AJF