Stuck bits on 11/73 Clearpoint 4MB memory - how to repair?

Hi, Seems I have bits 4 and 3 sticking on my Clearpoint QRAM-2-SAB-1 88b 4MB memory in my pdp11/73. Can anyone offer hints as to how to identify which component is broken and how to go about repairing this? It's the only memory board in this machine, so I guess the problem might actually be a bus or processor board, right? I have no other q-bus memory to test with, so can't do swapping / process of elimination to be sure. Here's the manual: http://www.arclightindustries.com/docs/Clearpoint-88B.pdf (which I probably should add to manx or archive.org or something). Here's a snippet of the VMJA diags run illustrating bits 4 and 3 sticking. During the next VMJA run, all addresses were showing up as errored instead of just the ones ending in xxx000xx, so I guess it's getting worse! @173000g Starting system BOOTING UP XXDP-XM EXTENDED MONITOR XXDP-XM EXTENDED MONITOR - XXDP V2.5 REVISION: F0 BOOTED FROM DL0 124KW OF MEMORY NON-UNIBUS SYSTEM RESTART ADDRESS: 152000 TYPE "H" FOR HELP ! .R VMJA?? VMJAB0.BIC CVMJAB0 ECC/PARITY MEMORY DIAGNOSTIC 11/83 CACHE AVAILABLE SWR = 000000 NEW = 000040 CSR MAP CSR 0 1 2 3 4 5 6 7 8 9 A B C D E F MEMTYPE P CSR NUMBER 0 CONTROLS TOO MANY BANKS 2044K OF Q-BUS PARITY MEMORY 2044K WORDS OF MEMORY TOTAL MEMORY CONFIGURATION MAP 16K WORD BANKS 1 2 3 4 5 6 7 012345670123456701234567012345670123456701234567012345670123 ERRORS MEMTYPE PPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPP CSR 000000000000000000000000000000000000000000000000000000000000 PROTECT PP 1 1 1 1 1 1 1 0 1 2 3 4 5 6 456701234567012345670123456701234567012345670123456701234567 ERRORS MEMTYPE PPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPP CSR 000000000000000000000000000000000000000000000000000000000000 PROTECT 1 7 01234567 ERRORS MEMTYPE PPPPPPPP CSR 00000000 PROTECT MEMORY DATA ERROR PC BANK VADD PADD GOOD BAD XOR CSR MTYP INT PAT 027606 10 060000 01000000 000010 000030 000020 0 P 27 027606 10 060002 01000002 000010 000030 000020 0 P 27 027606 10 060004 01000004 000010 000030 000020 0 P 27 027606 10 060006 01000006 000010 000030 000020 0 P 27 027606 10 060010 01000010 000010 000030 000020 0 P 27 027606 11 060000 01100000 000011 000031 000020 0 P 27 027606 11 060002 01100002 000011 000031 000020 0 P 27 027606 11 060004 01100004 000011 000031 000020 0 P 27 027606 11 060006 01100006 000011 000031 000020 0 P 27 027606 11 060010 01100010 000011 000031 000020 0 P 27 027606 12 060000 01200000 000012 000032 000020 0 P 27 027606 12 060002 01200002 000012 000032 000020 0 P 27 027606 12 060004 01200004 000012 000032 000020 0 P 27 027606 12 060006 01200006 000012 000032 000020 0 P 27 027606 12 060010 01200010 000012 000032 000020 0 P 27 027606 13 060000 01300000 000013 000033 000020 0 P 27 027606 13 060002 01300002 000013 000033 000020 0 P 27 027606 13 060004 01300004 000013 000033 000020 0 P 27 027606 13 060006 01300006 000013 000033 000020 0 P 27 027606 13 060010 01300010 000013 000033 000020 0 P 27 027606 14 060000 01400000 000014 000034 000020 0 P 27 027606 14 060002 01400002 000014 000034 000020 0 P 27 027606 14 060004 01400004 000014 000034 000020 0 P 27 027606 14 060006 01400006 000014 000034 000020 0 P 27 027606 14 060010 01400010 000014 000034 000020 0 P 27 027606 15 060000 01500000 000015 000035 000020 0 P 27 027606 15 060002 01500002 000015 000035 000020 0 P 27 027606 15 060004 01500004 000015 000035 000020 0 P 27 027606 15 060006 01500006 000015 000035 000020 0 P 27 027606 15 060010 01500010 000015 000035 000020 0 P 27 027606 16 060000 01600000 000016 000036 000020 0 P 27 027606 16 060002 01600002 000016 000036 000020 0 P 27 027606 16 060004 01600004 000016 000036 000020 0 P 27 027606 16 060006 01600006 000016 000036 000020 0 P 27 027606 16 060010 01600010 000016 000036 000020 0 P 27 027606 17 060000 01700000 000017 000037 000020 0 P 27 027606 17 060002 01700002 000017 000037 000020 0 P 27 027606 17 060004 01700004 000017 000037 000020 0 P 27 027606 17 060006 01700006 000017 000037 000020 0 P 27 027606 17 060010 01700010 000017 000037 000020 0 P 27 027606 20 060000 02000000 000020 000030 000010 0 P 27 027606 20 060002 02000002 000020 000030 000010 0 P 27 027606 20 060004 02000004 000020 000030 000010 0 P 27 027606 20 060006 02000006 000020 000030 000010 0 P 27 027606 20 060010 02000010 000020 000030 000010 0 P 27 027606 21 060000 02100000 000021 000031 000010 0 P 27 027606 21 060002 02100002 000021 000031 000010 0 P 27 027606 21 060004 02100004 000021 000031 000010 0 P 27 027606 21 060006 02100006 000021 000031 000010 0 P 27 027606 21 060010 02100010 000021 000031 000010 0 P 27 027606 22 060000 02200000 000022 000032 000010 0 P 27 027606 22 060002 02200002 000022 000032 000010 0 P 27 027606 22 060004 02200004 000022 000032 000010 0 P 27 027606 22 060006 02200006 000022 000032 000010 0 P 27 027606 22 060010 02200010 000022 000032 000010 0 P 27 027606 23 060000 02300000 000023 000033 000010 0 P 27 027606 23 060002 02300002 000023 000033 000010 0 P 27 027606 23 060004 02300004 000023 000033 000010 0 P 27 027606 23 060006 02300006 000023 000033 000010 0 P 27 027606 23 060010 02300010 000023 000033 000010 0 P 27 027606 24 060000 02400000 000024 000034 000010 0 P 27 027606 24 060002 02400002 000024 000034 000010 0 P 27 027606 24 060004 02400004 000024 000034 000010 0 P 27 027606 24 060006 02400006 000024 000034 000010 0 P 27 027606 24 060010 02400010 000024 000034 000010 0 P 27 027606 25 060000 02500000 000025 000035 000010 0 P 27 027606 25 060002 02500002 000025 000035 000010 0 P 27 027606 25 060004 02500004 000025 000035 000010 0 P 27 027606 25 060006 02500006 000025 000035 000010 0 P 27 027606 25 060010 02500010 000025 000035 000010 0 P 27 027606 26 060000 02600000 000026 000036 000010 0 P 27 027606 26 060002 02600002 000026 000036 000010 0 P 27 027606 26 060004 02600004 000026 000036 000010 0 P 27 027606 26 060006 02600006 000026 000036 000010 0 P 27 027606 26 060010 02600010 000026 000036 000010 0 P 27 027606 27 060000 02700000 000027 000037 000010 0 P 27 027606 27 060002 02700002 000027 000037 000010 0 P 27 027606 27 060004 02700004 000027 000037 000010 0 P 27 027606 27 060006 02700006 000027 000037 000010 0 P 27 027606 27 060010 02700010 000027 000037 000010 0 P 27 027606 30 060000 03000000 177747 177767 000020 0 P 27 027606 30 060002 03000002 177747 177767 000020 0 P 27 027606 30 060004 03000004 177747 177767 000020 0 P 27 027606 30 060006 03000006 177747 177767 000020 0 P 27 027606 30 060010 03000010 177747 177767 000020 0 P 27 027606 31 060000 03100000 177746 177766 000020 0 P 27 027606 31 060002 03100002 177746 177766 000020 0 P 27 027606 31 060004 03100004 177746 177766 000020 0 P 27 027606 31 060006 03100006 177746 177766 000020 0 P 27 027606 31 060010 03100010 177746 177766 000020 0 P 27 027606 32 06000