Lecroy Waveace 224 (Siglent) repair advice - Page 1
Forum section: electronics / repair

author: sbeube02
author_rank: Contributor
timestamp: February 06, 2024, 06:54:40 pm
content: Anyone familiar with troubleshooting a Lecroy/Siglentscope?I have this Waveace 224 with Siglent SAT7.820.682F main board.The oscilloscope seems to boot, I can hear some relays clicking, face LEDs goes on and off and display stay blank.Buttons are not responding.I have checked all rails coming from power supply, everything is fine.Checked the regulators on main board as per the Siglent SDS1000CFL user manual, all voltage are good.I also have the 25 MHz main clock OK.I checked with another scope the activity on the display ribbon cable, it seems to have some activity at 10 kHz and 8 MHz.There is also activity on the button board ribbon. When I press a button I can see the pattern on my other scope.Don't know where to look then?

author: shakalnokturn
author_rank: Super Contributor
timestamp: February 06, 2024, 10:03:41 pm
content: I think I saw this one selling for parts few weeks ago, I tried to get the price down before deciding it wasn't worth the fuss... I've had the same model to repair in the past, reallynotimpressed that LeCroy chose Siglent for their low end.It doesn't sound that dead. I suppose 8MHz is the pixel clock, 10kHz the H sync.Have you checked for activity on the LCD data lines?If there is some do you get a change blindly pushing a key?A white LCD like that could be caused by a missing supply from the scope mainboard or missing bias voltage generated on the LCD panel's electronics.

author: sbeube02
author_rank: Contributor
timestamp: February 07, 2024, 09:10:22 pm
content: That's really interesting. I am not familiar at all with display drivers and LCD protocols.The TFT controller is the Himax HX8817A. I will study the datasheet and look if the expected signals are correct.By the way, the oscilloscope does not appear to respond to any button press. No clic, no beep, no button LED change... Maybe the problem is not in the display driver but elsewhere, near the processor.I need also to connect to a PC and see if I can talk to him with USB or LAN.

author: tautech
author_rank: Super Contributor
timestamp: February 09, 2024, 06:36:38 am
content: AFAIK this a SDS1000CFL.https://int.siglent.com/products-overview/sds1000cfl/You can download all the docs for it here:https://int.siglent.com/products-document/sds1000cfl/#navsI would be removing the mainboard and checking the display ribbon cables and reseating them as necessary.Do be careful with the ribbon cable sockets as the latching mechanism for them is quite delicate and not hard to break.I don't know this model intimately however some models have a 2nd ribbon cable connector on the rear of the LCD which totals to 3 ribbon cable connectors to check.

author: sbeube02
author_rank: Contributor
timestamp: February 15, 2024, 12:13:09 pm
content: Thank you for the links.I tryed to remove the main board to get access to the display. There is absoultely no information on this display except the brand (SKS)?You are right, there is 2 ribbons and 3 connectors. Reseated all of them but no improvement.Tryed to connect to a computer with LeCroy Easyscope software. USB connection is not recognized on my computer.Ethernet does not work too with LeCroy software. Since I can't configure the scope IP address because the display is blank at the moment. I'm able to see the oscilloscope MAC address on my computer though.I made some measurements on the main board, there is activity on the processor pins, and flash and RAM as well.

author: tautech
author_rank: Super Contributor
timestamp: February 15, 2024, 01:14:26 pm
content: Quote from: sbeube02 on February 15, 2024, 12:13:09 pmYou must have NIVISA Runtime installed as a minimum for the correct connectivity (USB and/or LAN) drivers.USB should then connect without issues.Delete your LeCroy install then install NIVISA first then the later EasyScopeX:https://int.siglent.com/upload_file/zip/software/Oscilloscope/EasyscopeX_V1.01.02.01.22_EN.zipYou need follow this order or your PC OS will install the wrong USB driver then connection is not possible until the correct driver is assigned.See the attached doc.

author: nctnico
author_rank: Super Contributor
timestamp: February 15, 2024, 01:55:10 pm
content: If the scope doesn't respond to button presses, the main software isn't running. Probably crashes during startup due to flash corruption or faulty settings. The front panel has it's own controller doing button scanning so it is logical you see some signals there. Trying to connect with a PC is not going to help here. IIRC there are some ways to recover using a special USB stick or so. I'd go and try that route first.

author: sbeube02
author_rank: Contributor
timestamp: February 26, 2024, 01:43:34 pm
content: A bit more troubleshooting on this scope.By probing various chip, I can see activity on the Real Time Clock I2c lines at startup. Also activity on the flash and ram.I noticed a TX and RX test points but no activity on these lines. TX is held at 3.3V, RX is 0V. Maybe I should try to hook up a serial connexion to my PC and try to type something?

author: sbeube02
author_rank: Contributor
timestamp: March 31, 2024, 04:01:30 pm
content: Finally tried the failsafe boot procedure by pressing multiple times the Math button while power on and voilà! It is working properly.Not sure what had caused the previous issue, maybe corrupted firmware upgrade attempt?Very happy with the scope now 😊