Bricked Prolific USB to Serial Converter

[ambrossito]

I've been buying this cheap Chinese Prolific based USB-to-Serial Converters for a while and 3 out of 5 get bricked as soon as I connect them (ubuntu based platform). Before going further, I know the must be fake and that's that, but at least the tool provided from Prolific recognises the chips as "original". And by bricking I mean, both TxD and RxD lights are on all the time (and apparently there is no data transfer).

Any ideas??

PS: To make things worst, I don't currently have neither oscilloscope nor logic analyser
     

[katzohki]

Plug two in (preferably known, working to start with) and connect them together. Use a program such as Moba Xterm to test that they communicate. With this at least you could see what lines might be not communicating and so on. Best advice is going to stop buying them though.

[bjcuizon]

Did you consider other usb-serial converters as well...like the cp2102 iirc.

[Bicurico]

Newer drivers recognize fake Prolific chips and refuse to work.
Try installing older drivers and search Google on how to unbrick them.

Regards,
Vitor

[Lorenzo_1]

I gave up on Prolific-based USB:serial converters some years ago after having lots of problems with drivers that didn't work or were unreliable.  Spent many hours chasing possible causes and decided in the end it was either poor devices or poor drivers or both. Even had one catch fire while hooked between laptop and GPS unit.  I shifted over to a quality US brand (quite expensive) and have never used anything else since.  My Prolific converters were not from China but from reputable stores in Oz. 

[bson]

I try to avoid plugging USB to serial and various other devices into a Windows computer.  Instead I have a simple Linux Intel NUC that among other things runs a console server that can be ssh'd or telneted to.  It's accessible from anywhere on my network, logs all serial traffic (so I can go back and see what happened when something failed even if I'm not connected to a console), allows me to change a console from say the computer I'm working on to an overhead display to keep an eye on it, and so forth.  I stopped randomly attaching things to Windows for no reason after it bricked an apparently fake FTDI chip in a Drobo JBOD.

[stj]

check the soldering and the crystal,
it just sounds like bad hardware.

btw, i just ordered some more of these - they are very well designed.
almost like a piece of art.
http://www.ebay.co.uk/itm/201704657786

[sasa]

...
Any ideas??

Just throw it away and spare yourself a lot of headache and waste of time. Buy true FTDI / FT232RL based converter, for instance offered by Digitus.

I have bought long time ago allegedly a PL2303 based converter as no body imported real FTDI based one at the time. However, it never worked and I have wasted several days installing and testing many drivers with... Later I read most of them which are imported are fake.

[Assafl]

check the soldering and the crystal,
it just sounds like bad hardware.

btw, i just ordered some more of these - they are very well designed.
almost like a piece of art.
http://www.ebay.co.uk/itm/201704657786

Those are TTL level. I don't know what a real RS232 level will do to them....

[stj]

RS232 - +/-12v will blow them to hell
but i assumed this thread was about TTL adapters.

[Bicurico]

The problem with Prolific drivers is that they started to check if the IC is fake. When you purchase ANY device from China that comes with an RS232 interface and/or RS232 over USB, you MIGHT be getting a Prolific IC on board which almost certainly is fake.

Hence you must use old drivers to run the device. Prolific had a few driver revisions that apparently would BRICK fake IC's by deleting their firmware. I remember that there was a shitstorm after they did that, so newer firmware releases would simply refuse to work, but not brick the fakes.

Perhaps this link will help: http://wp.brodzinski.net/hardware/fake-pl2303-how-to-install/

Regards,
Vitor

[Assafl]

RS232 - +/-12v will blow them to hell
but i assumed this thread was about TTL adapters.

Hmm... Assumptions are the root of most errors....

In our local Arduino shack they tried to sell me an RS232 adapter that lacked the MAX2323 or Sipex voltage adapter chips....

Perhaps he tied them to 12v and that is why the OP's converters got bricked?

[stj]

dont know, he said nothing about the use or the units he has.
no pictures either - i like pictures. 

[T3sl4co1l]

Or old adapters.  I have a PL adapter that's old enough that it's not compatible with new drivers.  I reverted to the old version (that came with the adapter) and it's fine.

Also, that's long enough ago that I originally used those drivers in WinXP.

Tim