Yes, as I said in an earlier posting, having finally acquired a z80 pod, we have been using my working 9010a to test the bad one, and Bus Test is OK, and then going through the various tests described in the Service Manual. That's how we figured out that the U62 bank-select PROM was bad. Alas, the Watchdog and other auxiliary circuitry really can't be tested directly by the second 9010a. On 2017-08-10 5:47 PM, William Stillwell wrote: doesn't the 9010 run on a z80, just connect up your pod and test it. William Stillwell Board Member - Inspiration labs, Inc. a 501c3 organization Board Member - West Central Florida Group, Inc. a 501c3 organization Board Member & Co-Founder - Byte Amusement Group // Free Play Florida Arcade & Pinball Show a 501c3 organization Board Member - Clearwater Amateur Radio Society On Thu, Aug 10, 2017 at 5:37 PM, Grant Goodes [1]<grant.goodes@gmail.com> wrote: Another little tidbit: Before we fixed U62, you'd just get no display, and then after maybe 4 seconds, a beep, then nothing more. Now we still have no display, but the unit is silent for a good 8 seconds, and _then_ a beep, followed by a new beep every 4 seconds. The 4 seconds is the timeout on the watchdog. So the unit is doing something for the first 8 seconds, and then gives up and goes into a reset loop. Also, tested the display/keyboard unit in my good 9010a, and it is fine. grant.. On 2017-08-10 5:08 PM, Grant Goodes wrote: OK, I've been helping Robert with his problem (when I replied that I was helping my friend with a similar problem, I didn't realize he had joined the list and asked here about his problem! My friend and Robert are the same person!) We did some more debugging: * The U62 bank-select PROM _was_ bad, and having reprogrammed a new one with correct contents, are getting valid checksums for version 3A of the firmware on all the ROM contents * With the correct contents, and using Run UUT with the second 9010a, we hear a new beep every 4 seconds, but no display contents * We seem to be seeing a watchdog issue: Running the display and keyboard tests (triggered by writing non-zero values to 0x10081), we see the tests begin and then stop. In particular, the display tests should run continuously but they stop after ca. 4 seconds, which implicates the watchdog * Trying R14 to ground, which disables the watchdog, allows the display and keyboard tests to run normally: The display unit is fine * Testing out the Probe PIA, we seem to be seeing correct signals, but that testing uses the R14/watchdog-disable, so that may not prove anything. Does anyone have any ideas on how to debug the Watchdog? There really isn't that much in the Service Manual on this part of the circuit. grant.. On 2017-08-08 3:05 PM, robert via Techtoolslist wrote: my fluke 9010a rev 3a is not booting the diplay doesnt go on i think its a watch dog problem i have the service manual but it doesnt seem to cover the 3a rev fir mware for the rom signatures all my power test points are good and also i get a beep when power on but no display does anyone have any idea what could be the ca use of the shutdown _______________________________________________ Techtoolslist mailing list [[2]1]Techtoolslist@flippers.com [2][3]https://pairlist7.pair.net/mailman/listinfo/techtoolslist FTP site is: [3][4]ftp://ttl.arcadetech.org/TTL/Test_Equipment Archive site: [4][5]http://seven.pairlist.net/pipermail/techtoolslist/ References 1. [6]mailto:Techtoolslist@flippers.com 2. [7]https://pairlist7.pair.net/mailman/listinfo/techtoolslist 3. [8]ftp://ttl.arcadetech.org/TTL/Test_Equipment 4. [9]http://seven.pairlist.net/pipermail/techtoolslist/ _______________________________________________ Techtoolslist mailing list [10]Techtoolslist@flippers.com [11]https://pairlist7.pair.net/mailman/listinfo/techtoolslist FTP site is: [12]ftp://ttl.arcadetech.org/TTL/Test_Equipment Archive site: [13]http://seven.pairlist.net/pipermail/techtoolslist/ _______________________________________________ Techtoolslist mailing list [14]Techtoolslist@flippers.com [15]https://pairlist7.pair.net/mailman/listinfo/techtoolslist FTP site is: [16]ftp://ttl.arcadetech.org/TTL/Test_Equipment Archive site: [17]http://seven.pairlist.net/pipermail/techtoolslist/ References 1. mailto:grant.goodes@gmail.com 2. mailto:1]Techtoolslist@flippers.com 3. https://pairlist7.pair.net/mailman/listinfo/techtoolslist 4. ftp://ttl.arcadetech.org/TTL/Test_Equipment 5. http://seven.pairlist.net/pipermail/techtoolslist/ 6. mailto:Techtoolslist@flippers.com 7. https://pairlist7.pair.net/mailman/listinfo/techtoolslist 8. ftp://ttl.arcadetech.org/TTL/Test_Equipment 9. http://seven.pairlist.net/pipermail/techtoolslist/ 10. mailto:Techtoolslist@flippers.com 11. https://pairlist7.pair.net/mailman/listinfo/techtoolslist 12. ftp://ttl.arcadetech.org/TTL/Test_Equipment 13. http://seven.pairlist.net/pipermail/techtoolslist/ 14. mailto:Techtoolslist@flippers.com 15. https://pairlist7.pair.net/mailman/listinfo/techtoolslist 16. ftp://ttl.arcadetech.org/TTL/Test_Equipment 17. http://seven.pairlist.net/pipermail/techtoolslist/ _______________________________________________ Techtoolslist mailing list Techtoolslist@flippers.com https://pairlist7.pair.net/mailman/listinfo/techtoolslist FTP site is: ftp://ttl.arcadetech.org/TTL/Test_Equipment Archive site: http://seven.pairlist.net/pipermail/techtoolslist/