Hi everyone, i got a fluke 8506A sold as not working, the seller has described it as "it blows the fuse when power on".
I received the unit, the fuse was intact and configured correctly for 240V. It powered on with error 9.
There is a very nice article about the 8505A on xdevs, the 8505A is the same unit apart for the thermal rms converter module, the error rapresents a faulty module.
After removing the top cover it was apparent that something has released the magic smoke, so i removed the modules one by one to have a look.
The fuses were at least 3 transistor in the "ohm converters", two of them Q31 and Q29 Fluke specials fets
no. 393314. the third Q17 is a 2N3906, Q30 2N3904 looks it has overheat the pcb under it
Without the "ohm converters" installed the meter seems working just fine, respond to the commands, measure dcv correctly but nothing on ac, this time it does not yield any errors.
I will take some time for inspetting the rest of the unit and taking some pictures to share.
I do not think that the ohms converter is savable, but i would like to hear your opinions.
Soon i will update about the rms converter.