I suppose the 3.3V reg is used to power USB so the USB interface operates at reduced voltage without this connection because of losses in the internal regulator. Not a big deal if it works, but I would fix it.
I suppose the 3.3V reg is used to power USB so the USB interface operates at reduced voltage without this connection because of losses in the internal regulator. Not a big deal if it works, but I would fix it.
I tried to do what you said, I disconnected pin 28 and left only pin 9 powered, the device didn't turn on. I believe that there are other components within the integrated circuit that need power from pin 28.
No, that's not what I meant. It looks like everything on this chip runs from VCC except for USB communications which require 3.3V.
When VCC=5V the chip generates V3 internally. When VCC=3.3V the internal regulator will output less than 3.3V on V3 so USB may work if you are lucky or it may sometimes fail to work. That's why you short V3 toVCC.
Hi,
I have a CH341A Pro black "edition" and I tried to read some chips using clamp (chips are on board soldered), first the Detect doesn't work - ok china - i have selected the correct chip from list and read the chip.
on second read some data shifted and I was like this is not ok the chip is a Winbond W25X10
I have tried on different chip a PMC PM25LV512A which was read ok multiple times - erase - write - all good, strange but works with PMC not with Winbond which I need.
So I have searched the web and saw this post about the voltage, checked mine - 5V everywhere and I have started the mod using the OP
Lifted the pin 28 connect to C3 then to 1117 tested - success 3.3V - tried to Detect the chip still not working, tried to read, erase, program all error
Then I have tried next mod pin 28 to 1117 and pin 9 to 1117 - 3.3V but the same errors
Any ideas?
Thank you!
No, that's not what I meant. It looks like everything on this chip runs from VCC except for USB communications which require 3.3V.
When VCC=5V the chip generates V3 internally. When VCC=3.3V the internal regulator will output less than 3.3V on V3 so USB may work if you are lucky or it may sometimes fail to work. That's why you short V3 toVCC.
Now I get it. I measured it and the difference between Vcc and V3 was about 130 millivolt, there is a loss of voltage too.
It's like 78xx, the regulator starts to become unstable (with noise, variation and the whole thing) when the input voltage stays the same with the output voltage.
I made the change, thank you all!
@Mcast, that's a nice neat job you should be proud of.
If you want to mod it to be a switchable 3.3V/5V programmer, in addition to the Vcc pin lift already discussed, you need to add a tiny DPDT switch with one pole switching Vcc between 3.3V from the LM1117-3.3V, and 5V (via a polyfuse), and the other shorting V3 to Vcc in the 3.3V position to bypass the internal regulator. Where to mount it is the problem - if its small enough it may be possible to solder the switch body to the ground track along the board edge next to the three capacitors by the regulator, otherwise epoxying it on top of the CH341A chip would be a sensible option.
There's a good page about this programmer here:
https://www.onetransistor.eu/2017/08/ch341a-mini-programmer-schematic.htmlFinally, for those of you less experienced with SMD rework and board mods *PLEASE* for your and our sanity, and to reduce the risk of snapping the Vcc pin, get some 28 or 30 AWG Kynar wirewrap wire or magnet wire to do the mod with! If you *MUST* use stranded wire it needs to be something really thin and flexible, but with a good quality core,e.g. a single wire stripped from an old 80 wire UDMA PATA cable, ends carefully stripped, pre-tinned and trimmed to length *BEFORE* making the joints, and you need an order of magnitude more skill to get a decent result with stranded wire.
@Mcast, that's a nice neat job you should be proud of.
If you want to mod it to be a switchable 3.3V/5V programmer, in addition to the Vcc pin lift already discussed, you need to add a tiny DPDT switch with one pole switching Vcc between 3.3V from the LM1117-3.3V, and 5V (via a polyfuse), and the other shorting V3 to Vcc in the 3.3V position to bypass the internal regulator. Where to mount it is the problem - if its small enough it may be possible to solder the switch body to the ground track along the board edge next to the three capacitors by the regulator, otherwise epoxying it on top of the CH341A chip would be a sensible option.
There's a good page about this programmer here: https://www.onetransistor.eu/2017/08/ch341a-mini-programmer-schematic.html
Finally, for those of you less experienced with SMD rework and board mods *PLEASE* for your and our sanity, and to reduce the risk of snapping the Vcc pin, get some 28 or 30 AWG Kynar wirewrap wire or magnet wire to do the mod with! If you *MUST* use stranded wire it needs to be something really thin and flexible, but with a good quality core,e.g. a single wire stripped from an old 80 wire UDMA PATA cable, ends carefully stripped, pre-tinned and trimmed to length *BEFORE* making the joints, and you need an order of magnitude more skill to get a decent result with stranded wire.
I was really thinking about this upgrade, but there are 2 obstacles for me: I really care about the aesthetics of the adapter and the most of the memories I use, work at 3.3 volts. Maybe I will make a separate box to hold the new sockets and switches. Thanks for the tip!
It was mentioned in this link (in Russian):
https://savagemessiahzine.com/forum/index.php?showtopic=884713&st=1880that there is yet another fault in the design to reset / set the QE bit in the second status register. (please scroll down till you reach the supported chip model section)
It included some pictures but they were not very clear. (I have pulled the pictures and attached here)
Is this a known issue or could someone better at this shed some light into this please?
The common CH341A programmer boards cant use quad SPI mode for faster programming as the extra data I/O lines from the CH341A chip aren't connected to anything. It would be theoretically possible, *if* the right connections were present, but would need software support and would probably be incompatible with the use of the usual software and ordinary non-quad SPI FLASH chips in the same socket.
There is however a limitation of how the ZIF socket is wired, that's incompatible with certain SPI FLASH chips *IF* they have been configured for quad SPI mode, which uses those pins as I/O so naturally cant tolerate them being shorted to rails. Unfortunately the bit in question in the FLASH chip's status register is non-volatile so quad SPI mode is 'sticky', as opposed to the sane alternative of making that bit volatile and having the host processor configure the chip appropriately for the application circuit on startup. See
Winbond's W25Q64FV datasheet for details.
The proposed mod is simply to make three track cuts disconnecting those pins from the Vcc trace on the bottom side running under the ZIF socket, to add a wire link to patch the interrupted Vcc track back together, leaving out the /HOLD pin, then to fit pullup resistors from the Vcc track to the /HOLD and /WP pins. *IF* you need the capability to program DIP-8 package SPI FLASH chips with non-volatile quad SPI mode, and to be able to enable that mode with the chip in the ZIF socket you need to do the mod. Some magnet wire and a couple of 0402 10K resistors should let you do it very neatly. Any resistors bigger than 0603 will be problematic due to the limited space between the Vcc track and the /Wp pin. Otherwise, if you are programming in circuit, simply make sure your test clip lead includes 10K resistors in series with the /HOLD and /WP pins.
I see. Many thanks!
This maybe off topic for this thread. But do you know much about read/writing spi nand with the CH341A? There is a software called SNANDer but I have not been able to get consistent read out of this. Reading a 128MB spi nand chip will always have a few bytes different.
https://github.com/McMCCRU/SNANDerAny idea? possible bad chip?
Hi to people of eevblog forum! I wish I found this thread before the damage was done, 3v3 vcc and 5v on data… oh well.
For inspiration I wanted to share my execution of the 3V3/5V mod with spdt switch on the layout @jakeisprobably traced, big thanks for that!
- Cut 3V3 track going from the middle pin of voltage regulator
- Add a capacitor to the output of that regulator just to be sure
- Lift the VCC pin, insulate with capton tape underneath and connect it to the cut ex3V3 track right next to it
- Add a spdt switch or jumper to choose voltage on that ex3V3 track
- Add a shottky from voltage regulator output to pin 9
Hi'all,
Actually, there's a much easy way to do this fix; you just have to cut a track on the board and add a plastic jumper on pins labeled '3.3V' and '5V'. I've have successfully flashed a Winbond 25Q64FVSIG which is a 3V chip.
Cheers!
https://www.geocities.ws/racejay/ch341a/3.3V_Easy_Fix.jpg
I've just wanted to stop by to thank the original author, and all the contributors which helped me to make up my mind.
In the end I went with the "no solder" modification as suggested by "RaceJay". Of cause I've read that V3 (pin 9) should be connected to 3.3V, but it appears that this was not required to successfully program the 25Q128 BIOS chip in my HP Folio 9480m.
Hi,
I modded my CH341A, but I don't get 3.3V when verifying voltage.
- GND > CLK 3,18V
- GND > CS 3,24V
- GND > MOSI 3,19V
- GND > MIOS 3,18V
I was able to read Thinkpad T440p's EEPROM, but is it safe to write chip with these voltages?
Probably. The Thinkpad T440P has two Serial FLASH chips
[ref], a W25Q32FV and a W25Q64FV. Winbond state both have an operating voltage range from 2.7V to 3.6V,
[ref] but buried in the datasheets, you'll also find the requirement that
Note:
1.VCC voltage during Read can operate across the min and max range but should not exceed ±10% of the programming
(erase/write) voltage.
Check your programmer's 3.3V regulator output voltage, while connected to the target. I suspect its somewhere near 3.2V. Also check the Thinkpad's 3.3V rail voltage, powered on *WITHOUT* the programmer connected. The datasheets say +/-10% difference (but still within the 2.7V to 3.6V range) is permissible. I'd want some safety margin, so if the two measured voltages differ by less than 0.17V (slightly over 5%) it will be OK to write the FLASH.
Hello there!
I got one of these today, and I noticed the PCB layout of mine is different compared to the one posted in this forum by jakeisprobably. Also, the YJ text is missing on the back
With that said, it is still sadly 5v powered. I tried to read a chip without modding. Unfortunately I killed some other chips on the bus.
I did the mod and the chip reads fine, but sadly the board (a USB to SATA adapter) is dead
For being a soldering noob, surprisingly didn't end up ripping the pin off
You didn't rip a pin off because you used thin enough solid wire, as I advised back in reply #55.
All I can say about your soldering without being cruel is: Solder joints are meant to be shiny and have generally concave fillets that 'blend' where they meet the wire, pin or pad, not be grey and blobby. The latter are signs of a 'dry' (bad) joint, too much solder and either movement while it cooled, not enough heat or a lack of flux, maybe due to carrying
* the solder to the joint on the bit so the flux core burnt off before it got there - Always apply the solder to the work, never to the bit (except after wiping it, the bit needs a tiny drop put on it for good heat transfer).
However if it works, best to leave it for now. I strongly recommend practicing adding mod-wires to scrap boards, and also removing and replacing components on them to improve your skills before you work on anything valuable. The time to learn is *NOW* so don't wait till you desperately need the skills.
* Carrying solder on the bit for as short a time as possible is permissible, indeed necessary, for certain specialist techniques (e.g. drag soldering) but *ALWAYS* with extra electronics grade flux pre-applied to the work.
How to convert a 1.8v adapter and separate WP and HLD with resistors to VCC to read and write QUAD QE
Will it be possible to save a flash dump, because the adapter's transmitter is one way directional
Does it make sense to remod WP and HLD on both the ch341a itself and on the 1.8 adapter
Did anyone have pictures of the WP and HLD conversion via resistors on the 1.8v adapter
Thanks to you
what software do people use on this ? i see lots of boards but no seller mentions the software. is there such a thing as a generic spi / i2c software as well ( not just targeting eeproms, but more general where you can rea/write anything or even sniff a bus ?
I just gave up for this very reason (software hard to find, sketchy sources, etc). There are at least 3 packages that I could find and it took a long time to find those. Keep in mind I didn't test any of them since I didn't have a CH341A dongle. I've since closed all those tabs, but AsProgrammer was one and CH341PAR.EXE was another.
I ordered a FlashCat and will report on my findings after I try it.
what software do people use on this ? i see lots of boards but no seller mentions the software. is there such a thing as a generic spi / i2c software as well ( not just targeting eeproms, but more general where you can rea/write anything or even sniff a bus ?
The free Flashrom program is very good.
https://www.flashrom.org/Flashrom
what software do people use on this ? i see lots of boards but no seller mentions the software. is there such a thing as a generic spi / i2c software as well ( not just targeting eeproms, but more general where you can rea/write anything or even sniff a bus ?
Apparently NeoProgrammer works great with it, although I've never used it myself.
The creator is posting the software on
4PDA which requires registration for downloading, but the russian captchas are a pain...so here is a link:
NeoProgrammer V2.2.0.10.zip
I bought a black CH341A and made the recommended modification. I measured pin28 and data lines, all have 3.3V.
I use Neoprogrammer V.2.2.0.10. I can read a chip, erase it, and verify it is blank but I can not write to it
I checked with 3 different chips (BY25Q64, BY25D16, P25Q16H) and 2 computers (one Win10, the other Win11).
Every time I try to write, Neoprogrammer hangs (not responding) and CH341A disconnects (hear a sound, red light ON but yellow goes OFF).
Is CH341A faulty?
I bought a black CH341A and made the recommended modification. I measured pin28 and data lines, all have 3.3V.
I use Neoprogrammer V.2.2.0.10. I can read a chip, erase it, and verify it is blank but I can not write to it
I checked with 3 different chips (BY25Q64, BY25D16, P25Q16H) and 2 computers (one Win10, the other Win11).
Every time I try to write, Neoprogrammer hangs (not responding) and CH341A disconnects (hear a sound, red light ON but yellow goes OFF).
Is CH341A faulty?
Check the datasheet for the chip you may need to lift a pin to disable write protect, happened to me with a tcon board for a tv.