EEVblog Electronics Community Forum
Electronics => Repair => Topic started by: IbnBattutiFrutti on March 01, 2024, 10:27:58 pm
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I recently got a damaged U1272A on ebay. It appears to have suffered some sort of crushing impact, which destroyed the LCD and the knob.
Getting replacements from Keysight was simple enough, but there's some component damage that I spotted on the PCB. One IC with some lifted pads and six cracked ceramic SMD caps. Fixing the pads is no trouble, but reading values from cracked caps definitely is.
I've marked the numbers and locations on the attached image (not my board, taken from Dave's teardown video). Would anyone out there be willing to measure a few caps on their U1272A? :-DMM
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Any takers? Alternately, does anyone have any experience getting this kind of info from Keysight/Agilent support? I can't imagine they give it out, but I don't know for certain.
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Check the data sheets for the chips closest to the capacitors in question. They might give some clue as to the capacitor value. Cracked SMD capacitors usually indicates and over voltage scenario. I wouldn't be surprised is some of the chips are fried as well.
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Cracked SMD capacitors usually indicates and over voltage scenario.
Where did you hear this nonsense? Cracked MLCC means mechanical stress/impact.
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C153 is connected in parallel to at least 3 other same looking caps. So desolder one of them and measure.
C127 10nF
C110 ~4pF
Color indicates caps above are either C0G or other stable ceramic.
C114 and C109 2.2nF
C106 120nF
Color indicates these are X7R or similar unstable ceramic.
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You are a life saver! Thank you so much!