Tektronix 2445B Error code "Test 5 fail 44" Help - Page 1
Forum section: electronics / testgear

author: MeloMel
author_rank: Newbie
timestamp: April 04, 2014, 05:47:07 pm
content: Hello All,I've had this2445Bscope for years but haven't used it in quite some time.I take it out, dust it off and turn it on and I receive the following error message on the screen"Test 05 Fail 44"I looked up the error in the service manual and the explanation was"Main Board Positive level too positive"I'm not sure how to proceed from here? Has anyone else had this error before? What did you do to fix it?Any help will be appreciatedMel

author: BravoV
author_rank: Super Contributor
timestamp: April 04, 2014, 06:08:14 pm
content: Not an expert, but the 1st thing came out of my mind is to check the J119 for system voltages with DMM, or better if you have other working scope to see if they're good especially those lines with 1 or 2 mV ripple requirements.Beware, those hybrid ICs are easily die of overheating or get their life shortened if not cooled, especially without the metal enclosure since there will be no air flow at all.Use a big fan (not those tiny/puny computer fan) to blow the "whole" A1 board.

author: MeloMel
author_rank: Newbie
timestamp: April 04, 2014, 10:12:44 pm
content: Thanks BravoV, I can check the system voltages.Part of the error message includes the instructions to press the A/B Trigger to exit.When I press the A/B Trigger, the baseline level (supposed to be a reasonably flat line) is about 4X too thick and looks as if it has a noise component to it? I turned up the focus knob and the baseline disappeared. ?I turned the scope off and then on again and there is (no readout at all) no error message and no baseline trace.This problem has moved from bad to worse after I turned the "Readout Intensity" knob?I'll let you know what voltages I find at the J119.Does any of my symptoms ring a bell for anyone else?Mel

author: cristian71
author_rank: Newbie
timestamp: September 15, 2014, 09:13:05 am
content: Hello ,have the same problem :"Test 5 fail 44" to a 2467B.Where we have indicated the following: 1.= -14.87V, 2.= +4.98V, 3.= -18.14V, 4.= +9.95V, 5.= -4.96V, 6.= +14.93, 7.= ?, 8.=+86.5V, 9.=+41.9V, 10.=?, 11.=-8V, 12.=+4.95, 13.=?, 14.=?.7,10,13,14 probably nothing by the meter UNI-T UT70B.Capacitors in power are good,a little more uF,no less.Initially not display anything on the screen.Modifying GRID BIAS started to see some things but not horizontal line without probe.I think it goes horizontal deflection for line track.We found the line after I turned the potentiometer VERT, near U600.It is very low. Fail to pick up only to go down.Probably when I measured the last time I used it set too high or too low and I do not think voltage exceeded 200V, but the scale was inappropriate.INTENSITY potentiometer littel work .Please help me fix it.

author: Krischu
author_rank: Newbie
timestamp: December 26, 2014, 01:08:18 pm
content: HI, I'm new to this forum and I joined in the hope to get help in repairing my 2445B scope which is issueing the exact same error: Test 05 fail 44.I checked all voltages at the test jumper J119 as indicated above to no avail.All voltages are in range. Also no line frequency ripple of any significance.When I exit the test (pressing A/B Trigger as suggested), the time base doesn't show. Readouts at bottom and to indicating time base and vertical range show ok. Instead of the time base I see some dotted lines and a vertical line at the left margin of the screen.What else single test could I run instead?I have a 2465 service manual that doesn't seem to have the circuit diagrams in it that match the actual state of the scope. Also I have a CD containing a SM, that seems to match.How do I locate a component on the PCB, btw? I don't see component placment layout drawings at all? Just lists of components with placement coordinates.