Solartron/Schlumberger7060 Repair

[DVM-James]

Got this old toy some weeks ago. It works fine for some hours. But one day the display was dark - selftest  didn´t run.
So I carefully broke the original solartron-seals and opened the covers. Measuring the powersupply-voltages, I found the +15 V at +21 V !
The 7815-regulator was gone. After replaced it, the Selftest was o.k. so far. After "GBIB OFF" only two bars were on the left side.
So I had to explore a little bit around and overcross the diagrams and found the two loops around the integrator/comparators (ADC).
To make it easier for me to get the right track to measure and following the loops, I did some drawings by hand and notes to understand how it works. ( or You can say: what was first - the egg or the hen ?) I found out, it would be fine to open the loops by removing the JFETs that normaly switches the + and - REF. and "ZERO". ( I removed the JFET TR204 for the -REF. only, because there was -8 V (static) on the summing-point  TP203 / input of the integrator )( Got this hint on chapter 5 / page 2.31 ff into the service-manual for the 7061/62 ! )
Now the integrator started - showing some telefone-nos. on the display ( DC V-input shorted ). Measuring my selfmade track, I found my "friend" after a short time: IC 816A ( oscilloscope-picture shows an input "LOW" on pin2 on channel1 and the output pin12 or TP804 ("slave bistable clock" ) on channel2 - that was 600 mV only - not a good logic "HIGH" )

After renewed the 74LS10: "machine was repaired"
To make it a little bit easier for DYSers, hobbyists (and professionals ?), I made my drawings and measurements a little bit chic and have attached it here.
As the most DMM from the Solartron70xx-series work so, it may be helpfull for repair anyway.
I´ve also attached the bin-code for that 2532-EPROM ( checksum : 5DA00 hex ).

btw.: It´s a 7060G - so the AC-RMS-Volt/Amp.-option is mounted. It would be interesting to get some information regarding the AD6024-RMS-hybride. ( data-sheet ) I couldn´t  find anything about it.

For now - best regards + have a nice time.

[DVM-James]

- and one missing attachment !