EEVblog Electronics Community Forum
Electronics => Repair => Topic started by: uoemx on September 19, 2023, 03:39:02 pm
-
My GW instek GPD-3303S power supply has the following error:
When I load the program for the pic18f85J10 using the ISP port of the t48 (tl866-3G) loader, the power supply jumps in random numbers. I removed the 93c66 memory ic and cleared it, the power supply showed a relatively standard voltage and the current error was about 100mA. After that, when I went into calibration, the power supply no longer displayed the correct current but had a very large error.
But the external current meter displays correctly, only the display on the power supply jumps wildly.
At that time, I deleted the memory of ic 93c66 and the device displayed the correct voltage, but the current error was about 100mA. I updated firmware to ver 2.9 and 2.11 but it didn't work. I cannot access it by command via MTTY because the power supply is not responding. I suspect the firmware has errors in both the PIC18F85J10 mcu and the 93C66 memory ic. So, if you own this power supply, please help me read the firmware program.
2 First picture without calibrating the power supply.
The next 2 pictures are the power supply after calibration
The last 2 pictures when calibrating but re-measuring amps with Fluke 179
Here is the firmware I read from my GW instek GPD-3303S power supply
https://www.mediafire.com/folder/00ztfjvaucbtc/2 (https://www.mediafire.com/folder/00ztfjvaucbtc/2)
If I have to repair hardware, which part should I check because I have repaired it a few times before
Sorry my English is so bad
Thank you very much!
-
Here is the schematic: https://www.mediafire.com/file/5ktdrde0p6b0ucs/GPD3303SM.pdf/file (https://www.mediafire.com/file/5ktdrde0p6b0ucs/GPD3303SM.pdf/file)