Front End Repair for Deaf 1000MP by Marios 5B4WN
Problem: I recently blew the
front-end of my 1000MP from too much neighbouring RF during contesting (WRTC).
No RX on both main and subVFO on ALL BANDS from 100KHz to 29MHz. VE7SV
pointed me to VA3CR' site a
similar problem solved by replacing D1056
from the IF board (on MkV). As I could not locate D1056 I assumed that
the MkV and 1000MP have different circuitry. Based on the symptoms and
looking at the diagram I located D1033 (1SV196) which seems to be the
only pin diode that is common on all bands.
Looking at the FT1000MP MKV technical manual it was apparent that that
D1056 is the "same" diode as D1033 on the circuit diagram (see photo)
BUT on the 1000MP is 1SV196 and on the MkV is
1SV271TPH3. The circuit
around both diodes is exactly the same in both radios and since I had an
1SV271TPH3 available (thanks VE7SV) I decided to change this. I
opened
the radio as described by OH6RX and removed the IF board. D1033 is an SMD located on the undersurface of the radio next to the leg of L1039
(see photo). Use extreme care if you plan to use a normal soldering iron
as you may damage the tracks around it! I replaced it with an 1SV271
(check for correct polarity) and that did the trick! The receiver came
back to life!

