EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: mwbarth36 on January 13, 2020, 08:23:06 pm
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I have a DSO3202A scope which has the following problem, it will not run the 'Self Calibration' sequence. Continues to display the message "Disconnect all Inputs", even when all inputs are disconnected. What's more, looking at the inputs there is no sign of abnormal voltage or resistance. I suspect the problem is with channel 1. That is where the Self Cal. program starts, and it never advances past trying to get channel 1 input to indicate that there is nothing connected. Also, both channels operate normally with signal, and are right on, spec. wise. The only thing I can find is that when Channel 1 is switched from the 100 mV/div position to the 50 mVdiv position the reference is no longer 0, but goes to a -150mV level, and stays at that level when switching lower to the 20 mV/div position. All other positions of the vertical settings are 'spot on', and the scope appears to operate normally, with AC gain accurate on both channels. Normally I would expect the Self Cal. to correct problem at the lower setting on Ch. 1.......except the Self Cal. will not start because the program 'thinks' there is something connected to one of the inputs, presumably Ch 1.
Of course, it appears impossible to get a circuit diagram for this scope. If wrong please let me know. I would appreciate any help I can get in solving this problem, as the scope appears in good shape other than this problem. I have opened the scope and compared measurements of components in the channel 1 and channel 2 attenuators, and can find nothing different between the two. Cannot power up the scope in the disassembled state to check voltages.
Any ideas greatly appreciated!
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Check for damage on ch1 in 50 ohm mode as it's often where mistakes are made and inputs get overloaded.
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There is no 'Mode' setting for the DSO3202A scope. It is fixed at 1 Meg. Have replaced many 50 Ohm R's in scopes with a 50 Ohm input setting.
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There is no 'Mode' setting for the DSO3202A scope. It is fixed at 1 Meg. Have replaced many 50 Ohm R's in scopes with a 50 Ohm input setting.
Ok yes you are right.
https://literature.cdn.keysight.com/litweb/pdf/5989-2235EN.pdf?id=638687
Dunno what to suggest then. :(
Aren't these made by Rigol ?
Maybe hunting out info on the old DS1052 might find something.
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I have heard the DSO3202A is a re-branded Rigol but can not confirm. Even if true, appears just as difficult to find circuit diagrams for the Rigol mode. If anyone has any information on the Regol scope I would try to check out how similar the two are.