Can't debug LPC8N04

m_spit — Wed, 11 Mar 2020 07:36:39 GMT

Hi,

I have some troubles with debugging my LPC8N04 devkit board in MCUXpresso. Compiling an example program goes without errors or warnings, but when I press the blue debug button, the following error occurs

Exception
Reason:
Unable to open probe index 1.
Error: Probe not open

With error codes

Unable to open probe index 1.
Error: Probe not open

Unable to open probe index 1.
Error: Probe not open

Error: Probe not open

   at com.nxp.mcuxpresso.core.debug.support.linkserver.redlink.client.RedlinkServerClient.checkServerReply(RedlinkServerClient.java:214)
   at com.nxp.mcuxpresso.core.debug.support.linkserver.redlink.client.RedlinkServerClient.openByIndex(RedlinkServerClient.java:740)
   at com.nxp.mcuxpresso.core.debug.support.linkserver.emulators.jtag.AbstractJtagDiscovery.ideConnect(AbstractJtagDiscovery.java:205)
   at com.nxp.mcuxpresso.core.debug.support.linkserver.emulators.jtag.AbstractJtagDiscovery.connect(AbstractJtagDiscovery.java:187)
   at com.nxp.mcuxpresso.core.debug.support.linkserver.emulators.jtag.AbstractJtagDiscovery.discover(AbstractJtagDiscovery.java:146)
   at com.nxp.mcuxpresso.core.debug.support.linkserver.emulators.TargetDiscovery.jtagDiscovery(TargetDiscovery.java:457)
   at com.nxp.mcuxpresso.core.debug.support.linkserver.launch.LaunchScriptUtils.getEmulatorInfo(LaunchScriptUtils.java:248)
   at com.nxp.mcuxpresso.core.debug.support.linkserver.launch.LaunchScriptUtils.init(LaunchScriptUtils.java:488)
   at com.nxp.mcuxpresso.core.debug.support.linkserver.launch.LaunchScriptUtils.<init>(LaunchScriptUtils.java:156)
   at com.nxp.mcuxpresso.core.debug.support.linkserver.launch.LaunchScriptUtils.<init>(LaunchScriptUtils.java:143)
   at com.nxp.mcuxpresso.core.debug.support.linkserver.services.TargetDiscoveryService.getTargetDiscovery(TargetDiscoveryService.java:138)
   at com.nxp.mcuxpresso.core.debug.support.linkserver.override.LSFinalLaunchSequence$TargetDiscoveryJob.run(LSFinalLaunchSequence.java:110)
   at org.eclipse.core.internal.jobs.Worker.run(Worker.java:63)

And after an automatic retry, 3 other error messages saying it can't connect with the chips debug port.

The console says this:

Reconnected to existing LinkServer process.
Connecting to probe 1 core 0 (using server started externally) reports:
'Ee(42). Could not connect to core.'
Retrying...
Reconnected to existing LinkServer process.
Server OK but no connection to probe 1 core 0 (after 3 attempts) - Ee(42). Could not connect to core.
============= SCRIPT: lpc8n04connect.scp =============
Error: Probe not open
Reset pin state: 00
Error: Probe not open
Error: Probe not open
Error: Probe not open
Error: Probe not open
Error: Probe not open
============= END SCRIPT =============================
Failed on connect: Ee(42). Could not connect to core.
No connection to chip's debug port

So what I've tried:

Googling the issue. This issue seems not been fixed by anyone
Checked the linkserver with the red 'chain' and 'boot' icons, it is OK
Checked the VCOM driver, it shows up as "NXP LPC11Uxx VCOM", which is as to be expected
Checked devices and printers, shows up as LPC11U3x CMSIS-DAP v1.0.7, as to be expected
Reinstalled MCUXpresso, also with new workspaces and a full whipe from my pc, multiple times
Checked the debug settings. The device is automatically detected, no weird settings found
Different example codes compiled and tried to debug them
Tried debugging with batteries in the coin-cell holders
Different USB cable
Different USB port, as well as powered USB hub
Updated the LPC11Uxx firmware
Played around a lot with the jumper settings for SBW debug
Pressed and hold reset and S2, switched S1, tried every possible combination
Checked the components on the hardware. I did notice that D44 and D45 are defective (broken off) while this board is brand new.
Checked if the demo app still works with an Android smartphone
Unplugged all other USB devices
Checked all updates of MCUXpresso
Checked the BSP of the devkit
Watched all startguides of the devkit, showing that they can normally debug out of the box (which I can't)
Checked firewall settings
Reinstalled motherboard chipset drivers on computer

What I'm planning to try:

Ask help on the forum (hello there)
Different PC, since this is a hardware dev machine, eclipse and/or usb drivers might collide with other hardware development things
Different IDE?

Re: Can't debug LPC8N04

m_spit — Wed, 11 Mar 2020 09:26:16 GMT

Apparently the devkit works on a different windows machine.

The board however, still doesn't work on the original machine. I tried wiping almost every USB driver on this machine and ran a cleaning program, those also didn't work.

There's something weird going on in the Windows drivers but I don't know what.

Re: Can't debug LPC8N04

converse — Wed, 11 Mar 2020 18:13:39 GMT

It could be a firewall problem. Check that the firewall is not blocking MCUxpresso and redlinkserv.

Re: Can't debug LPC8N04

m_spit — Thu, 12 Mar 2020 07:14:08 GMT

I checked the firewall settings again. I now gave explicit permission through my firewall for both MCUXpresso and Redlinkserv in both personal as public networks, but it didn't solve the issue..

Re: Can't debug LPC8N04

nxf58474 — Thu, 19 Mar 2020 18:47:47 GMT

Hi,

Hope you are doing well. Could you please try to reinstall the drivers, it could fix the problem. You can download the LPCSCRYPT, when you install it, all LPC drivers are installed.

Let me know your results

Best Regards,

Ricardo

Re: Can't debug LPC8N04

Marouane — Mon, 28 Sep 2020 19:20:12 GMT

same probleme with LPCS55S69

Re: Can't debug LPC8N04

kamasara — Wed, 18 Mar 2026 04:40:45 GMT

I, too, have been facing the same issue with this development board (OM40002). What helped me was using Segger's J-Link (even their cheapest Edu Mini will work) as external debugger to flash erase the LPC8N04 using the GUI Flash tool of MCUXpresso IDE. Make sure to connect jumper P1, turn on Switch S1 and use a coin cell to power the target.

I know I am quite late to this. But I hope it helps someone else who is starting new with this chip.

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