| Electronics > Repair |
| CH341A Serial Memory Programmer Power Supply Fix |
| << < (22/25) > >> |
| flachyjoe:
The chipset is CH341B 406725D24 |
| Tantratron:
It seems lot of CH341x variants after all :) |
| Ian.M:
Ch341B shares a datasheet with CH341A: http://bitsavers.informatik.uni-stuttgart.de/components/wch/_dataSheets/CH341DS1.PDF and has exactly the same power pin specifications and I/O voltage levels. If with the jumper removed, you still have >3.3V signal levels when idle on the SPI pins (1-4 of the same header as the jumper), or have 5V on pin 28 (Vcc) of the CH341x IC (corner nearest board edge and ZIF socket), you need to do the mod. |
| flachyjoe:
3.332V at the 2 places so it's good. :) Thank you two! |
| Tantratron:
Hello @Ian.M and @flachyjoe First question to Ian because I'm bit confused or lost plus I'm not native english so I did not fully understand what exact voltage test, what pins should be done --- Quote from: Ian.M on November 16, 2024, 11:36:05 am ---If with the jumper removed, you still have >3.3V signal levels when idle on the SPI pins (1-4 of the same header as the jumper), or have 5V on pin 28 (Vcc) of the CH341x IC (corner nearest board edge and ZIF socket), you need to do the mod. --- End quote --- There should 2 tests, one with the jumper installed and then with no jumper, correct ? As mentioned earlier, I've bought from amazon the CH341A programmer board. Wether the jumper is installed, I do have always +5V on these pins: CH431-28 ZIF-1 ZIF-2 ZIF-5 and ZIF-6. By ZIF here I mean, the socekt plug dedicated for 25XX then on this same connector, I always have +3.3V on ZIF-3 ZIF-7 and ZIF-8 What do you mean by 3.3V then what do you mean by 1-4... do you mean 5V, do you mean pin measurement voltage between ZIF-1 (CS) and ZIF-4 (GND) ? --- Quote from: flachyjoe on November 16, 2024, 12:33:52 pm ---3.332V at the 2 places so it's good. :) --- End quote --- Second question for flachyjoe, can you detail exactly what places (which pins) did you get 3.3V ? You said to purchased on eBay in France this model https://www.ebay.fr/itm/324505422583 . The picture and title of the french eBay-vendor shows CH341A but you said the item in your hand has CH341B. Do you confirm it has 3.3V on all ZIF pins and Chip-28 so you do not need to make any modification ? Third and last question to Ian, When reading the beginning of the thread started in 2017, I see that you modified and edited part your post #3 I do not know what was the description to modify back then, I just want to make sure that the easiest way to modify and make sure no 3.3V flash chip to be fried consists to do this re-wiring No track cuts, just lift pin 28 (easy because its near the board edge with nothing in the way) and run a wire from the lifted pin across to pin 9, and on to the 3.3V regulator output. Thank to take time clarifying your posts so it will safe. The reason I ask is first I'm not native english, second the thread has been going with 5 pages with other modifications so I prefer to really have say a 2024 final update. Albert |
| Navigation |
| Message Index |
| Next page |
| Previous page |