Hi,
May be trivial, but this has happened to me. Check all the ribbon
cable connections between the boards. I had one that got pulled out
partially when I folded out the board, and was causing all kinds of
weird symptoms. Check that all all firmly seated in their connectors.
If it never completed self cal, there may be garbage in the nvram, so
once you get the scope running, I recommend to do a Cold Start to
clear it, otherwise it may get very much confused.
Also, check the ripple on the power lines, that may be out of spec.
While I'm no fan of the common Internet wisdom of 'recapping cures
everything', I had 3 24xx DSO, and all of them had bad/marginal caps
in the PSU, so I guess one can safely assume that those caps need
replacing. Don't forget about C244 in the control power supply.
Szabolcs
RichR via Groups.Io <choicetrans1@...> ezt ¨ªrta
(id?pont: 2018. j¨²n. 27., Sze, 23:53):
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I recently purchased a 2440 with a 4000 code, battery weak. Everything else appeared to be working. That was the only fault code. I replaced the two ram modules with new. The original were obsolete (DS1235BWL-120) so I purchased DS1230-100+. When I first turned on the scope everything powered up and there were plenty of fault codes so I started a self calibration. It never completed the self calibration. The scope went blank. I was able to power it up only occasionally until it stopped completely. It no longer tries to test when it is powered on the only lights on are the three GPIB lights. The screen will start with some erroneous dots and then go blank. I have tested the low power board and have some readings that do not match the schematics The voltage reading according to the power supply overcurrent check page 478 of the manual do not match. The voltages on the side board are correct so I am not sure where to proceed. I have attached a - of the readings I got from the power supply. Any help is greatly appreciated. Thank you, Rich
/g/TekScopes/files/015-0282-00/TEK%202440%20Power%20supply%20test/TEK2440%20Curret%20test20180627_12351992.pdf
