Siglent SDG2042X Funtion Generator not booting - Page 1
Forum section: electronics / repair

author: DaJMasta
author_rank: Super Contributor
timestamp: February 03, 2020, 06:31:36 am
content: I've got an SDG2042X that's refusing to boot. Fan comes on, activity seems to happen inside, but nothing on the screen or front panel, and no obvious signs of actually being booted. Inside, voltages on the analog board seem fine and the LED lights normally, voltages on the digital board seem fine with the exception of the 16V for backlight power (though this seems to be controlled by the main processor, so I suspect this works it's just not getting that far). The LED on the digital board lights and appears quite dim (maybe PWM, haven't checked yet).I connected up a serial port to the data I saw coming out and I'm reading a "C" on the serial port output every second or so, but nothing else. I'll be poking around some more and taking some more measurements, but does anyone have a way of running internal diagnostics, hardware resets, or specific low-level stuff to check?If it helps anyone's future troubleshooting, the serial TX from the board is on the unpopulated header next to the 5V marked on the silkscreen. C157 is the backlight voltage cap, where U8 is the switching mosfet for the L31/D8 step up converter for it.

author: Gixy
author_rank: Regular Contributor
timestamp: February 03, 2020, 06:51:20 am
content: Did you try to reload a firmware from a USB key?

author: DaJMasta
author_rank: Super Contributor
timestamp: February 03, 2020, 07:11:38 am
content: Is that possible without any response on the front panel (I have verified logic power, so some kind of keystroke set could work, but I don't know if that exists for the unit)?If there's a way to do it, I'd be happy to try, but I haven't seen any methodology of how to do it in my brief searches.

author: tautech
author_rank: Super Contributor
timestamp: February 03, 2020, 07:48:08 am
content: Have you checked out the troubleshooting section starting P66 in the service manual ?http://siglentna.com/wp-content/uploads/dlm_uploads/2017/10/SDG2000X_ServiceManual_SM0202X-E01A.pdfBoot recovery is generally only used if boot only gets to the splash screen and no further.If it gets that far I have the recovery files but we need to get life out of it first.

author: DaJMasta
author_rank: Super Contributor
timestamp: February 03, 2020, 05:34:01 pm
content: The troubleshooting list for the problems I'm seeing seems to be pretty short.No 16V on main digital board -> contact SiglentNo display on the front panel/screen after checking cables -> contact SiglentI haven't checked the 25MHz clock on the digital board yet, but since I am seeing RS232 data out at a reasonable baud rate, I'm assuming that's not the issue. I've also checked the caps near the DDR voltage regulator and the processor regulator chip (not listed on the troubleshooting steps) and while I haven't checked the datasheet to see the actual requirements, but they seem normal (1.1V, 1.5V, 1.8V, etc.) Running the digital board without the output board results in the same, everything coming from the power supply itself seems to be good. No excessive heating observed on the thermal camera.