[DSP-10] Problems with Serial Shift Registers.

[Chuck E. Swedblom]

Hi,

My DSP10 had a failure and I traced it to U107 using
the UDIAG2 diagnostic program.  I replaced U107 and
U108 and the problem still exists.

The UGDIAG1 shows that the serial lines are OK but
UGDIAG2 gives the following for U107:  Pin 3 is zero
should be 5V, pin 4 is 5V should be zero and pin 7 is
zero should be 5V.  U108 lines are OK.

The DSP10 displays the regular screen with the error:
'PLL not locked'.  The 19.68MHz LO tunes both sides
of this, but the output of U6 is at 9V.  The 10MHz ref.
is OK on pin 1 and FIN pin 4 has a good 19.68 signal.

The F_IN pin 8 on U104 has a good signal in the 123MHz
to129MHz range.  The 10MHz Ref signal is OK.

I need this transceiver very much for use at the  Owens Valley
Radio Observatory, OVRO, using their 40 Meter Telescope
at 10GHz.  The Kenwood I have been using just don't cut it!!

Can someone shed some light on my dele ma?

Chuck  WA6EXV