Serial Number:355 (EAC/Radiomarine R7)
Year of Manufacture:1973 (7331 latest observed IC date code)
Date of Receipt:2016 Feb (for examination & repair only)
State upon Receipt: Several knobs have been replaced with non-original types. Functional but some erratic behaviour. The wire-pin connectors on the PCBs - which were intended to allow disconnection of the wires for board removal - have been soldered over. These connectors were cheap and unreliable.

Date:2016 Feb
Symptoms: Sensitivity / reception is erratic with turning of tuning switches.
Examination: Tracked to broken solder joint between pin and PCB around antenna input on rear-most board.
Procedure: Resoldered.

Date:2016 Feb
Symptoms: Reception still erratic with jiggling around 4th board from rear.
Examination: Poor soldering of wire-pin (white-blue wire) on 4rd board from rear.
Procedure: Resoldered.

Date:2016 Feb
Symptoms: When tuning into the upper overlap region (above the top of the 100KHz VFO span) when the hundreds-KHz knob is at '9' - that is, when a carry into the MHz digits is necessary - 6 is added to the MHz display rather than 1. E.g. the display transitions from 01,999.9 to 07,000.0 rather than 02,000.0 .
Examination: Somehow the 'carry' wafer (3rd from front) of the hundreds-KHz switch had been installed rotated 180 degrees.
Procedure: Knob and shaft slid out so wafer could be rotated to correct position, knob and shaft reinserted.

Date:2016 Feb
Symptoms: Erratic display in the hundreds-Hz and units-KHz digits, observable with jiggling of the counter board.
Examination: Solder joints at edge connector on display board appear to be fractured. Edge connector not seated fully.
Procedure: Edge connector removed, reseated and resoldered.

Also, new solder posts for two wire connections on display board created, due to lifting PCB trace.

Date:2016 Feb
Symptoms: Units-KHz digit oscillates between odd/even, affected slightly by pushing on counter board.
Examination: Bad solder joint to U1703.13, 1 & 8 bits don't get latched. Top-side trace is soldered directly to pin due to lack of plated-through holes. Solder was balled and not flowed properly.
Procedure: Resoldered.

Date:2016 Feb
Symptoms: Hundreds-Hz digit still erratic, notably going from 0 to 8, again affected by pushing on counter board.
Examination: 8-bit going high when it shouldn't at U1802 (74141) but stable back at U1702 (7475).
Procedure: 1 & 8 bit lines resoldered on display board at edge connector and U1802.