Pin Function Voltage readings --- -------- ---------------- 1 Cavity side oven +4.008339300 +3.830757500 +3.727102760 +3.701473490 +3.749514980 +3.883599170 +4.101180520 +4.327096750 +4.646089010 +4.945850790 +5.271056200 +5.565458360 +5.840739650 +6.089354920 +6.284934880 +6.440003730 +6.545062570 +6.609647340 +6.658109500 +6.669503260 +6.646524550 +6.615819140 +6.567553130 +6.488518180 +6.377710780 +6.241521990 +6.043849840 +5.774328230 +5.514178080 +5.204939610 +4.885354920 +4.578803360 +4.300148350 +4.063463280 +3.885285240 +3.766540590 +3.727404780 +3.759331080 +3.877540230 +4.045033800 +4.285095540 +4.568831680 +4.894084480 +5.209927600 +5.558319650 +5.819926910 +6.091287370 +6.286615080 2 Ground return for pin 1 +0.007970742 +0.008055460 +0.008152882 +0.008229021 +0.008300657 +0.008350124 +0.008381493 +0.008398267 +0.008401721 +0.008387679 +0.008378868 3 +0.000134945 +0.000020193 +0.000182518 -0.000120906 +0.000186057 +0.000032303 -0.000025633 +0.000124374 -0.000025724 +0.000033975 4 +0.000014092 +0.000277455 +0.000215099 +0.000157997 +0.000130907 -0.000094844 +0.000124283 +0.000171718 +0.000191837 5 +0.000115607 +0.000226856 +0.000198046 +0.000317476 +0.000267447 +0.000168405 +0.000372520 +0.000219158 +0.000169336 +0.000502599 6 +0.000211386 +0.000336386 -0.000001564 -0.000022198 +0.000050755 +0.000121365 +0.000151858 +0.000346329 +0.000502885 -0.000494637 7 +0.000485942 +0.000600747 +0.000434221 +0.000675134 +0.000617969 +0.000515930 +0.000438851 +0.000642316 +0.000689413 +0.000442809 8 +16V return for pin 9 +16.321981100 +16.319944500 +16.317717500 +16.315383800 +16.313004000 +16.310420400 +16.308284600 +16.305982400 +16.304381300 +16.302814900 +16.301550800 +16.300563500 9 Cavity side oven thermistor +13.948123300 +13.948518800 +13.948645000 +13.948436200 +13.947960600 +13.947427800 +13.946950000 +13.946168900 +13.945671200 +13.945333100 +13.945263500 +13.945499000 10 Cavity bottom oven +5.872221440 +5.928952600 +6.045182340 +6.221052340 +6.404520080 +6.634479990 +6.893590150 +7.172903930 +7.467987710 +7.785698650 +8.111607730 +8.472735000 +8.765009330 +9.106223600 +9.403722850 +9.711671580 +9.993403000 +10.248449100 +10.470738700 +10.665006800 +10.774819100 +10.860832900 +10.892442400 +10.863760400 +10.776344400 +10.646872500 +10.481070300 +10.291797100 +10.067438600 +9.827514350 +9.619795040 +9.390480740 +9.178427800 +8.999509390 +8.842693430 +8.705373830 +8.587482890 +8.501407930 +8.433622590 +8.392268350 +8.371986460 +8.379781040 +8.407955000 +8.443989140 +8.497410140 +8.566684380 +8.643164410 +8.727989540 +8.820908500 +8.916534750 +9.019387950 11 Ground return for pin 10 +0.007271947 +0.007269705 +0.007269666 +0.007277903 +0.007288115 +0.007302605 +0.007317714 +0.007337163 +0.007359898 +0.007382757 12 +0.000161264 +0.000190652 +0.000373831 +0.000191145 +0.000408134 +0.000163821 +0.000426515 -0.000008565 +0.000127572 +0.000330378 +0.000168932 -0.000303807 13 +0.000090065 +0.000113241 +0.000135814 +0.000325307 +0.000096647 +0.000269194 +0.000336963 +0.000324590 +0.000386887 +0.000172707 14 +0.000848414 +0.000580698 +0.000708027 +0.000636904 +0.000410226 +0.000568383 +0.000528564 +0.000493894 +0.000492222 +0.000564171 +0.001070796 15 Unknown (axial field?) +11.671595700 +11.671604000 +11.671554900 +11.671356000 +11.671470800 +11.671633300 +11.671707400 +11.671866600 +11.672043800 +11.672555400 +11.672694700 16 "" +11.668772400 +11.668818800 +11.668848300 +11.668870900 +11.668834800 +11.668794500 +11.668690900 +11.668575900 +11.668436900 +11.668305900 17 +16V return for pin 18 +16.338598300 +16.338613800 +16.338534300 +16.338345400 +16.338189900 +16.337909600 +16.337619200 +16.337296200 +16.336889700 +16.336508000 +16.336009900 18 Cavity bottom oven thermistor +13.996349400 +13.999303700 +14.002115500 +14.004948900 +14.007699200 +14.010413600 +14.013267100 +14.015519100 +14.017896200 +14.020223400 +14.022424200 +14.024540200 +14.026481500 +14.028403100 +14.030399100 +14.031983000 +14.033614200 +14.035147400 +14.036711800 +14.038177000 +14.039515100 +14.040805100 +14.042129700 +14.043403200 +14.044467100 +14.045665700 +14.046634300 +14.047661200 +14.048653000 +14.049540200 +14.006534900 +14.006996100 19 +0.000402927 +0.000530365 +0.000491247 +0.000434814 +0.000468177 +0.000302875 +0.000465810 +0.000214923 +0.000169879 +0.000209917 20 -0.000323077 +0.000004079 +0.000338225 +0.000246846 +0.000175244 +0.000328904 +0.000100261 +0.000117961 +0.000109875 +0.000370980 +0.000213355 +0.000500010 21 Unknown (male header pin 1) +0.005402952 +0.005155157 +0.004908731 +0.004677900 +0.004512221 +0.004351561 +0.004271525 +0.004334862 +0.004300749 +0.004253053 +0.004213379 +0.004177181 +0.004115171 +0.004152403 +0.004177667 +0.004179391 +0.004176705 22 +0.005538836 +0.005519994 +0.005512389 +0.005510890 +0.005509340 +0.005512621 +0.005513858 +0.005513726 +0.005505750 +0.005508810 +0.005515021 +0.005514408 23 +16V return for pin 24 +16.296735500 +16.296722600 +16.296746200 +16.296823200 +16.296676100 +16.296698000 +16.296736600 +16.296768700 +16.296697900 +16.296767800 +16.296758200 +16.296718900 24 Unknown window comparator function +14.223986400 +14.224689900 +14.224975800 +14.225397700 +14.225435700 +14.223613700 +14.208264400 +14.200458100 +14.197559000 +14.196080000 25 Unknown (female header pin 1) +0.008164293 +0.008049168 +0.007661966 +0.007852692 +0.008033848 +0.007913802 +0.007742082 +0.007893340 +0.007971610 +0.007855635 +0.007725846 26 Unknown (female header pin 2) +0.006732549 +0.006911305 +0.006623288 +0.006850133 +0.006823437 +0.006905745 +0.007116999 +0.006898075 +0.006787452 +0.006904240 +0.007056055 +0.007012667 Notes: 1) Voltage readings were recorded approximately 500 ms apart after approximately 1 hour of operation 2) Oven voltages 1-2 and 10-11 appear unstable because these readings were taken prior to replacement of the two capacitors at the 7824 regulator input and output pins 3) Thermistor inputs at pins 9 and 18 are connected directly to opamps with unlimited DC gain. Probing causes large output transients that take about 100 seconds to settle, even with the DMM in its high-resistance input mode 4) The above effect is more pronounced for the side oven than the bottom oven; need to verify that the bottom and side oven integrators use the same 100M resistor value 5) Oven heater windings are approximately 125 ohms (side) and 130 ohms (bottom) when cold, a few ohms lower when warm 6) Side oven thermistor resistance is approximately 116K cold, 97.4K warm; bottom oven thermistor is approximately 119K cold, 100K warm 7) Pin 23 had no visible connection on the PCB but appears to be tied to the +16V bus somewhere. May be connected to one of the +16V pins (8, 17) at the discriminator rather than the PCB? It appears to provide the +16V bias return for the element at pin 24, which is monitored by a comparator input pulled up to +8V with a 330K resistor 8) Voltage at pin 24 ramps up slowly from about 13.9V to 14.3V during warmup. Unknown what its purpose is. The comparator window is 14.43V - 15.06V with the 7.49V and 16.36V voltages actually measured for the +8 and +16 buses, so even after warmup, pin 24 is apparently still outside it? 9) Shell is unconnected