UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - HP-35665A Dynamic Signal Analyser

Terry295 · 18th Feb 2018, 4:22 am

Has anyone out there got any detailed service information for this instrument they could share please? I have a faulty unit and I believe that the problem lies in the 35665-66504 Ch2/A to D board.

I originally attempted a repair some time ago without success so I left the instrument alone for about 2-3 months. When I got round to it again it did successfully initialise twice but then the fault reappeared. The trouble shooting procedures I have indicate that the 66504 board is responsible.

I have inspected both the main power supply and the on-board regs (of the 66504 assy.), they all seem to be working OK but the instrument will not successfully complete its internal cal. A circuit of the 66504 board would, at this point, be a really great help in progressing this repair. Thank you

Terry C (ZL4TC)

18th Feb 2018, 4:22 am	#1
Terry295 Tetrode Join Date: Nov 2009 Location: Christchurch, New Zealand Posts: 64	HP-35665A Dynamic Signal Analyser Has anyone out there got any detailed service information for this instrument they could share please? I have a faulty unit and I believe that the problem lies in the 35665-66504 Ch2/A to D board. I originally attempted a repair some time ago without success so I left the instrument alone for about 2-3 months. When I got round to it again it did successfully initialise twice but then the fault reappeared. The trouble shooting procedures I have indicate that the 66504 board is responsible. I have inspected both the main power supply and the on-board regs (of the 66504 assy.), they all seem to be working OK but the instrument will not successfully complete its internal cal. A circuit of the 66504 board would, at this point, be a really great help in progressing this repair. Thank you Terry C (ZL4TC)