Elecraft KDSP2 Manual - Manual (Page 39)

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generator. Set the KDSP2 to 400 Hz center frequency and 300 Hz width. Turn up the AF GAIN until you
hear filtered background noise. Now, increase the center frequency of the filter. The noise pitch should
increase. If the pitch does not increase with each increases in indicated center frequency, there may be a
problem in the DSPx module. If the pitch increases, but then the noise suddenly becomes weak or absent,
you are probably beyond the passband of your current XFIL setting.
If this test shows a problem with the DSPx module, you may carefully remove and then re-install the Flash
memory chip in the socket on the DSPx board. Pay careful attention to the orientation of the Flash chip in
the socket before you remove, and re-install it in the same orientation. This is a polarized part, and
reversing it may damage the DSPx module or the Flash chip. If you are uncomfortable doing this, contact
Elecraft.
LED remains on.
The KDSP2 LED will normally come on at power up, then extinguish after a second or two. If it stays on,
it indicates that KDSP2 U1 and the DSPx module are not communicating properly.
Check U1, D3 and verify that the DSPx module is properly aligned and fully seated into its two connectors
on the KDSP2 module. It is easy to be off by one pin in the alignment of these connectors. Also make sure
that both rows of pins are inserted into J1.
Clock time doesn’t increment.
U3 may be installed backwards or is defective. The 32.768 kHz oscillator may not be running- check Y1
and C6. If you have a frequency counter or oscilloscope, probe U3 pin 3 and look for a 32.768 kHz
waveform.
Clock doesn’t keep time with K2 power turned off.
Make sure the Lithium cell is installed correctly. (Nothing will be damaged if the Lithium cell is installed
backwards, thanks to diode D4.) If you suspect the cell is bad, measure it with a voltmeter and replace it if
the voltage is less than about 2.5 volts.