(solved) DL24MP Identify SOT23-6 smd marking code 169 324

[selevo]

solution
https://www.eevblog.com/forum/repair/el-dl24mp-identify-sot23-6-smd-marking-code-169-324/msg5563845/#msg5563845

Hi!
This chip in electronic load DL24M, please help me identify it.
pin 4 it's out and connected with pin 1 LM321 (on 4pcs lm321)

[CaptainBucko]

Possibly https://product.torexsemi.com/system/files/series/xc6415.pdf but not realy sure.

Here are my notes on the DL24MP

- uC is a HC32L176 in a LQFP-48
- Bluetooth (Matching) - BPOK228-28A2 (made by https://www.zh-jieli.com/#)
- FETs are still IRFP264
- High Power Diode is a V40100C
- Analog to Digital seems to be now be performed by 2 x HLW8110 High Precision Power Metering IC (the wiki below suggests one of them is just used as an ADC ) - Datasheet attached.
- FETs are still controlled via LM321 op-amps
- ME6203 and ME6118A are used for linear voltage regulation

[selevo]

It's a Shanghai Belling (上海贝岭) BL1551B SPDT analog switch. The package is SC70-6, not SOT23-6. That's why dimensions are important for identification questions

https://electronics.stackexchange.com/questions/718412/identify-sot23-6-smd-marking-code-169-324/718449#718449
---------------
I also want to add that in the new firmware version (the brain is in the display unit) you can set the power to 3 kW. (in DL24MP) That is, the 600 W limit has actually been removed. If the transistors are moved to larger radiators, the scope of application increases significantly. Of course, it’s not the tracks on the board that need to be strengthened and the diode changed. now I'm just all this

DL24MP and DL24M
The head unit of these electronic loads also differs slightly with small changes. The control module with display from the dl24m load does not work with the DL24MP load, not finished self test on start
 but works the other way around.

[aix]

Since you mention the firmware, I thought I'd ask.  I have a DL24MP unit that gets stuck at the very start of the boot process, possibly during the self-test (not surewhat else it might be doing while showing that progress bar?)  See the attached pic.

I wonder if any of you have any suggestions for where to go looking for faults.

The unit is in a 300W configuration, with the main board and one expansion.  I have an encoder and an on/off button connected to the header above the LED flex cable. (I can remove all that for testing, but it involves a fair amount of disassembly and so I thought I'd ask first.)

[CaptainBucko]

I own two of the DL24MP, but I have never seen that issue. Sorry I cant help further.