What turned out to be a November-09 winter project almost went into summer-2010.
After much work this calculator is 100% operational. These are very rare in any condition. They are impossible to find in working condition. The scientific 360KT trip keyboard is amazing. In my 20 years following Wang calculator technology I have never seen or heard of another working 360kt.
This is my repair log:
I started with dead calculator in 10/2009.
I bought it as "works fine" off EBAY. Was ripped off...it had many issues.
This is what I did to fix:
#1)Cleaned all connectors....After step #1 calculator now took keyboard input about 50% of the time, but that is it.
#2)Replaced 1k POT in 513 logiblock card with vertical fine-tune model....Now display and keys work. Also all six core registers push/pop ok....but nothing else.
#3)Went over power supply...outside specifications on ripple, but when I doubled capacitors to bring ripple in check, no changes in calculator. 🙁
#4)Static in-circuit tested ALL transistors/diodes. Short-tested caps. Fixed a bad diode on 510 card...now some math functions work only when cold.
#5)Studied card functions and their schematics for two months. Determined that the 512-card's binary math card had a problem with BCD carry funtion...re-checked components again (came up OK). I boxed the calculator up (I had Fix-Wang-Burnout!) and put in closet. Next step was to scope out the logic and find specific location which was broken. A daunting task in that I was working with no guidance and was totally on my own. Decided to wait until December-2010 to start.
#6)I stumbled on another 512 card. Cleaned it up then scoped it. Once installed the electronics unit 100% works!
#7)Trig functions process for about 6 seconds and produce wrong answer (always the same wrong answer). After several months of studying patents (has great logic flow description) and scoping/debugging I got this working. A NAND gate (4 transistor logic assembly) on the keyboard #3 BCD was wonky. I replaced transistors on the gate and 360KT keyboard was repaired and working!
Dr. Wang was truly a visionary and hopefully will be remembered by history as a major contributor to computer evolution. This calculator highlights his most amazing accomplishments (magnetic core memory (he sold patent to IBM?), logarithmic math functions, BCD digital transistorized computer architecture).
This is for sale. Expensive. Please pm me for details. Includes Wang service manuals and patent technical writeup. I have a few spare logiblock cards that I have used for doner transistors.
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