| Electronics > Repair |
| Fluke PM6666 counter freezing after 3 seconds from turning on. |
| << < (15/27) > >> |
| FransW:
Anything I can do? Missing manual info? Frans |
| coromonadalix:
@Fransw Have you scanned the schematics ?? i did not see them if you posted the files here ? or i have missed them thks for your work |
| pizzigri:
OK, so redone the measure with 10x probe. The result is 385mV (forgot to set the scope to 10x) so that makes 3.85V. Therefore good. Bandwidth of the probes at 1x is 6MHz, so I thought that they would work at 5Mhz.... Measuring 72V AC dispersion as well across the chassis. Should I float it? Or add a 1K resistor to gnd pin on power lead? Today a new thing actually happened: the meter did not freeze with the GPIB connected. It happened once, but I did not notice it until I turned it off - that in fact the GPIB was connected to it - and then it did not do it again! I have a mighty headache. Today I cant do anything more, I will put myself back into it tomorrow! I believe that we are getting somewhere anyhow. I apologize, I am just a hobbyist however I'm learning more trying to figure out this than in years at school. Thank you for your help guys PS Frans, are there details on the I2C protocol in addition to what you already posted? |
| khs:
--- Quote from: pizzigri on October 12, 2020, 12:44:13 pm ---Thinkfat, Then, i disconnected the SDA line, still locked up. Then the SCL, and it unlocked, all this obviously with the meter powered. I am looking at the manual excerpts that FransW is posting, and the "Addr 10" is indeed the GPIB... --- End quote --- From my understanding the counter should run with the I²C SCL line connected, because the I²C SCL is an output from the CPU. Is there a difference of the SCL signal from the CPU connected to GPIB and the SCL signal not connected to GPIB? |
| coromonadalix:
yep the "SCL" clock should'nt be affected unless something is dragging it down ? How do you measure 72vac ? between the frame and the scope ground ?? for a scope it would be best to add an isolation transformer for safety reasons, unless you have a ground problem ??? Check if your screw(s) hole(s) are not transfering ground between the main board and the gpib board Ex passing thru a strud, an "pem" "punched stud in the metal" inserted in the metal etc ... |
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