Prolific PL-2303 problems

Some reliability issues have been detected with USB-RS232 adapters which report a Prolific PL-2303 chip.

Some adapters work have worked well, others don't.

Prolific has the following warning on their website:

Warning Notice:
Please be warned that counterfeit (fake)
PL-2303HX (Chip Rev A) USB to Serial Controller ICs using Prolific's trademark logo, brandname, and device drivers, were being sold in the China market. Counterfeit IC products show exactly the same outside chip markings but generally are of poor quality and causes Windows driver compatibility issues (Yellow Mark Error Code 10 in Device Manager). We issue this warning to all our customers and consumers to avoid confusion and false purchase.

In recent weeks, I have purchased two USB Interface cable for ICOM OPC-478U adapters from http://www.409shop.com/ (409 Shop) which do not work and gave Error Code 10 as indicated in Prolific's warning notice on counterfeit product, so they are probably counterfeit or fake.

409shop.com appear to be one of the suppliers of counterfeit Prolific based product. 409shop did agree to refund but require that I return the goods by tracked freight which will cost me more than the money to be refunded.

Fig 1:

Fig 1 shows a 'PL2303HX' chip which gives the symptoms described in the Prolific warning above. This is one of the adapters supplied by http://www.409shop.com/ (409 Shop).

Prolific supplies a utility program to check chip version, but it is apparently unreliable as it reports an FTDI adapter to be a PL-2303HXA.

One of Prolific's statements recommending only the PL-2303HXD raises concerns as to whether earlier chips will work in Windows 8:

Windows 8 is NOT supported in HXA/XA chip versions (will show yellow mark Error Code 10).

Windows 8 is supported only in following chip versions:

- PL2303HXD (HX Rev D), PL2303EA, PL2303RA, PL2303SA, PL2303TA, PL2303TB Download PL2303 CheckChipVersion tool program to check chip version.

I have some PL2303HXC based adapters branded ATEN. They would appear to be unsupported in Win8, and it puts pay to the suggestion to buy brand name product.

Sadly, the confusion, counterfeiting, upward compatibility and lack of reliable information and counterfeit detection from Prolific suggest that the safe option is to avoid Prolific chips altogether, and avoid 409 Shop.

The counterfeit chips seem to work with an older Prolific driver (V2), and there is suspicion that the problems using the current version Prolific drivers are a result of Prolific poisoning the driver so that it will not work with the alleged fake chips. It is also possible that is the root cause of the Win8 backwards compatibility. Running a back level driver for Win7 might work, but if Win7 takes it upon itself the update the driver, it will break. If this is Prolific's doing, it is a stunning mistake that will hand the market to the more capable and more reliable FTDI chips.

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