Lecroy Wavesurfer 24Xs PCI Gigabit Communicaton Error  - Page 1
Forum section: electronics / repair

author: Momchilo
author_rank: Regular Contributor
timestamp: August 29, 2023, 11:21:10 pm
content: Hi all,I guess my Lecroy Wavesurfer 24Xs scope has a hardware fault. It worked several years perfectly fine but since few days it shows an error message in X-Stream (attachment 1).PCI Card: Gigabit Communication ErrorSometimes the whole scope hangs up after the error message until I switch off the power. In the other cases I can close X-Stream and Windows is still working fine for hours.With this error I got the following provided error descriptions but not all at once (see additional attachments):parity error detectedCRC error detectedMAM phase error detectedtransfer done fifo not empty error detectedextractor error detectedcollision error detectedCODE error detectedThis error only appears after some few minutes and when the trigger is active. As long as the scope is "cold" it works as intended for all four channels. If the trigger is stopped the error does not appear. While this error happens I can hear the relais clicking. If the scope does not hang up after the error and I can close X-Stream, the acquisition board still shows up in the Windows device manager as working.For the same fault I could find this thread:LeCroyOwnersGroupSo far I reinstalled Windows to see if it was a software issue. It didn't help. Also I dissembled the whole scope, connected an external monitor to measure some voltages. I hope it is a power supply issue. But there are many different regulators and voltage supplies in difficult positions to measure. I couldn't find a fault so far. Measuring is not easy because the cables are very short and it is not possible to lay down the boards on the table next to each other. Maybe I will buy/build extension cables. The CMOS battery on the mainboard is nearly new and the voltage looks good. I upgraded the CPU, RAM and SSD few years ago. But I don't think the PC hardware is the source because Windows runs stable.I have no idea if the fault is on the PCI card or on the acquisition board. In the linked thread someone mentioned the PLL circuit: "MAM Phase error likely indicates a problem in the PLL circuitry on the acq board (that ‘synchronises’ the ADC’s and the acquisition memory)".I uploaded the service manual of the very similar Waverunner Xi family:https://file.io/G14sDC6o73z2The manual is without schematics but at least with some block diagrams.The next step will be to use ice spray to cool down different areas of the PCI card and acquisition board to see if I can locate the faulty area. Because it should work if it's cold. At least that is my best guess.I attached the log files from X-Stream as a zip-file. I think the most useful one is the HWError.mauiLOG. Inside this file the error "AAC Link failed" is mentioned quite often.I couldn't read the dump files of the error correctly with WinDbg. Not sure if it is my fault or if the files are not useful.I have already accepted the fact that the device is irreparably broken, but I want to try at least. I am very grateful for any hints or ideas.Best regardsMomchilo

author: Momchilo
author_rank: Regular Contributor
timestamp: August 29, 2023, 11:23:42 pm
content: Additional scope pictures in an additional post because of file attachment limitation

author: Momchilo
author_rank: Regular Contributor
timestamp: August 31, 2023, 10:07:49 pm
content: Does anyone know what they mean with MTT image disk or MAM data disk?I couldn't find any Google results and it is not mentioned in the service manual where I got the diagram from.

author: RamboChen
author_rank: Newbie
timestamp: October 08, 2023, 05:51:24 am
content: the service manual of the very similar Waverunner Xi family:https://file.io/G14sDC6o73z2The manual is without schematics but at least with some block diagrams.Hi, the link is lost, can you upload again?