Not All Nokia CA-42 Data Cables are the Same

[Tommy Tyler]

Warning: this thread is obsolete - it remains just for historical purposes.
Please see the following thread for updated info:
https://www.hifi-remote.com/forums/viewtopic.php?t=13928

Remember the old saying, "If something is too good to be true, . . . ." When I was writing the "gallon of gas" article I had two sample units to work with. One was DealExtreme SKU 45715 and the other was SKU 446. They were practically identical, and both worked fine as flash interfaces after modification. But I looked at that bewildering array of similar looking items on eBay and couldn't help wondering why they were priced so randomly. How could a store sell an item for $12.95, or more, and expect to compete with an offer right below his for $2.39? Was there really a difference in the product that made it worth that much? I wanted to find a good, reliable, low-priced supplier of data cables for our members, present and future, to rely on.

So I placed orders for a quantity of three data cables from each of five different suppliers, to sample the products and see if they were identical.

• The first two suppliers were DealExtreme, to see if the data cables were still the same as my previous samples.
• The third was an eBay seller called salei2011 selling item #150708478795 for $2.39 each.
• The fourth was an eBay seller called topvshow selling item #290425651135 for $2.68 each.
• The fifth was a seller called bigdigshop2008 selling item #250990225472 for $2.79 each.

All five orders were placed on Feb 10. The first of them arrived in the mail yesterday, from eBay seller salei2011, and my worst nightmare came true. Although it looks like any other data cable, closer examination shows it is really quite different. It is nearly impossible to open up for modification.

The unit is packaged in what is called a double-shot molding. First, the circuit board assembly is inserted into a mold and a slightly flexible black plastic is injected to completely enclose it. Then that molding is inserted into a larger mold and slightly flexible blue plastic is injected to give it the appearance you see above. There are no case halves to snap apart. It is one solid piece, and the only way to get it open is to cut it open, very tedious (and dangerous). The clue in the picture is those four little holes you see in the enclosure. Those were left by pins in the mold that support the PCB to keep it centered while the molten plastic is injected. Other items that identify this manufacturer are no printed label on the unit, and CA-42 molded into one side in small, raised letters. So don't buy from salei2011, or any other vendor if you can see those tell-tale holes in the picture. Oddly enough, this is a more elegant, more costly method of assembly than the case molded in two halves and snapped together, yet it has the lowest price on eBay. Go figure.

Let's use this thread for users to post the outcome when they buy a cable,. Tell us who you bought it from, and was the unit a snap open enclosure (easy to modify) or a one-piece molded job (avoid it like the plague). Over time we will build up a list of the good guys.

[The Robman]

I would also like to know if it has to be a CA-42 cable, because I see several other Nokia cables with other CA-xx labels.

[Kevin Timmerman]

The unit is packaged in what is called a double-shot molding. First, the circuit board assembly is inserted into a mold and a slightly flexible black plastic is injected to completely enclose it. Then that molding is inserted into a larger mold and slightly flexible blue plastic is injected to give it the appearance you see above. There are no case halves to snap apart. It is one solid piece, and the only way to get it open is to cut it open, very tedious (and dangerous).

I have purchased many low cost USB to serial cables, including various Nokia cables, over the past 5 years or so. All of the Nokia cables where double shot molding and had to be carefully cut apart. Almost all of the cables had fake Prolific PL2303 chips or a variety of other "no-name" USB to serial chips. Some of the cables worked well enough to be usable, but most had various problems that limited their usefulness or rendered them useless. My conclusion was that these low cost cables are not worth the hassle. Spending $15 to $20 on a general purpose FTDI BOB (or make your own) that can be used for many applications and work reliably is a greatly preferred solution.

Some of the problems with the fake PL2303 chips are:
- Requires special driver version - this is a big red flag that it is fake
- Locks up after a while
- No tx and/or rx data activity
- Not reliably recognized by the computer
- Gets hot

Typical molded Nokia cable

The PCB inside


The fake chips are typically COB (chip on board) packaging, the genuine chips are usually SSOP or SOIC package.

[Kevin Timmerman]

I would also like to know if it has to be a CA-42 cable, because I see several other Nokia cables with other CA-xx labels.

CA-42 and DKU-5 are USB to serial. The others are not.

[The Robman]

Back to the original topic, looking at the 3 ebay listings, you can clearly see the molding pin holes in the listing for the bad cable that has arrived already, but the photos in the other two listings don't have these holes, so there's still a chance that these might be good (from our POV) cables. Of course, those could be stock pics, so we'll have to wait and see.

[eferz]

I had actually purchased the Nokia CA-42 cable after discussing building a JP2.1 cable with mdavej. This was prior to Tommy posting his handy how-to guide. However, I didn't have any time to play with it for a while. This cable was sourced through Amazon and bought it from ccmaccessories. Now I'm wondering whether or not the cables from DealExtreme are legitimate "Original Norkia Enhancements". According to Nokia's website, "For Nok or 'For Nokia XXXX' should not be listed on the product." but that's what is shown on Tommy's pictures.

For the genuine part, its USB's PCB is encased within multiple layers. The top layer is a single piece plastic boot. This is much more flexible plastic that Tommy's photos suggest. So when I tried to pry the sides open the boot, it just flexed and laughed at me... for about fifteen minutes. So, I actually had to slice it in half along the seam on one side to get it out from the first layer. This was done with a prison style shank to teach not to laugh at me ever again.

The next layer seems to be covered in a copper foil with a sort of shrinkable black tape wrapped around it. While I have gotten the black tape off of the copper foil, the foil itself appears to be impossible to remove with shredding into it. I do see signs of an opaque plastic which I suspect is suspending the PCB inside of it. Looks like because I have a genuine "Original Nokia Enhancement", I'm going to need extra time to delicately get to its innards.



After I got the copper foil off of the "Original Nokia Enhancement" there's just hard plastic. It looks like it was partially injection molded with the edges melted together. So it doesn't look like I'm going to be able to get to the PCB without breaking it. The good news is that there are five conductors in the cable but the bad news is I have no clue as to which one is connected to what.



At this point, I wished my original purchase was for the knock-offs from DealExtreme instead. *sigh* Anyways, the cable was mailed to Tommy for analysis.

[Tommy Tyler]

I received the second batch of three cables today, from bigdigshop, eBay item #250990225472. They were the unusable double-shot molded type.
So I looked closely at the ad for the third supplier, topvshow, and it has the tell-tale holes, so none of the three sources I sampled from eBay can be used.

I went through all the eBay ads again, looking for the small holes. Many of the pictures are too small and have such limited resolution that you can't tell whether they have holes. But also on many of them you can. To test two other methods of identification, I picked out another couple of sources and ordered samples, esaleseveryday item #260342168515, and yallstock item #230444644812. The pictures in both these ads clearly show only two grooves in the strain relief, a positive sign that they use the snap-together enclosure. The double-molded units have three grooves in the strain relief. Another identifying feature (although I'm not yet sure how reliable) is that the snap-together cases always have a paper label stuck on the side.

[Tommy Tyler]

eferz sent me the genuine Nokia CA-42 Connectivity Adapter Cable he purchased through Amazon. The construction of the unit is even more complex than he described. The PCB with USB connector and cable is first totally enclosed in Kapton tape and vacuum sealed so that the tape conforms to every tiny detail of components on the PCB like a thin skin. Then the entire assembly is inserted into an injection mold that encases it in what appears to be polyethelene plastic, very tough, hard to cut, and extremely difficult to remove. As described by eferz, a copper foil shield was wrapped around the polyethelene molding, and the cable shield was soldered to it. The foil was also soldered to the rear end of the USB connector. After enclosing the foil in black tape, probably to hold it tight for the final operation, the assembly is inserted into another injection mold and encased in a seamless outer jacket of blue, slightly flexible vinyl plastic.

That's a very thorough and expensive shielding job. Even the 5-conductor cable is double shielded, an inner foil shield within a fully braided shield. And nobody would ever solder directly to a USB connector housing unless it was done to control RFI leakage. There's an FCC compliance notice in the booklet, but nowhere in the printed material, on the product, or on the package is there an FCC ID number, so I can't look for details at the FCC site.

The complexity of this device is incredible. Not counting wires and connector, there are at least 45 components on the PCB, compared to just nine for the "inferior knockoffs" that Kevin puts down. In the picture, the large IC on top of the board is a 64-pin Atmel AT76C712 processor with every kind of built-in support you can imagine, USB, SIP, dual UARTs, timers, 16K ROM, 8K RAM, you name it. On the bottom of the board, the 8-pin IC is an Atmel 25128A 128K serial EEPROM. The 14-pin IC is marked 55A07A. I think it is an obsolete Atmel part, function unknown. Heaven only knows what's enclosed in the rectangular brick of rock-hard red epoxy on the bottom side. And I have no idea what the square ring of red epoxy covering the main processor pins, or the strip of epoxy covering the tips of the USB connector pins, is for.

In summary, if I had to guess I'd say the manufacturer of this product didn't want anyone taking it apart to try and reverse engineer it, as if anyone would want to. And the reasons it is a hopeless candidate for converting to a flash interface are pretty obvious.

[eferz]

eferz sent me the genuine Nokia CA-42 Connectivity Adapter Cable he purchased through Amazon. In summary, if I had to guess I'd say the manufacturer of this product didn't want anyone taking it apart to try and reverse engineer it, as if anyone would want to. And the reasons it is a hopeless candidate for converting to a flash interface are pretty obvious.

Darn. Sorry to hear that it can't be used. Any ideas what each of the cables do? Blinky said a couple of them were N/C but obviously from your pictures, the yellow cable is soldered to a resistor.

Heaven only knows what's enclosed in the rectangular brick of rock-hard red epoxy on the bottom side. And I have no idea what the square ring of red epoxy covering the main processor pins, or the strip of epoxy covering the tips of the USB connector pins, is for.

I don't know either but I love guessing. My first guess is the rectangular block is probably a crystal oscillator used for a clock in communications. As for the red epoxy, I'm assuming it used as a preventative measure for the heat of the polyethylene plastic from coming in contact to certain solder joints during manufacturing or use. I wouldn't be surprised if the epoxy demonstrated heat insulation properties.

EDIT: According to the High Speed (48MHz) AVR based Bridging Device AT76C712 document:

• Only One External Clock Crystal of 12MHz can generate all the required System Clocks:
• Internal Clock for Standard UART Rates
• A 48Mhz and 96Hmz clock for USB Data Recovery
• AVR Processor and System Clock

[The Robman]

Any idea what the BM07083821 number is?

Btw, I found this wiki page about the Nokia 6101 phone which says:

"Other problems include problems trying to connect the phone to a pc as many versions lack Bluetooth and many 6101s are only supplied with outdated Infrared (IR). The other option is connect the phone to a PC with a genuine Nokia Data cable which is usually very expensive often costing up to €50. Many 6101 users have been caught out by purchasing counterfeit cables such as CA-42 on internet sites like eBay with the cable priced very low from £0.99. Often originating in Hong Kong or Mainland China, the counterfeit cables will not then connect the phone to the Nokia PC Suite. These products contain characteristics such as Nokia spelled NOK and the CDs supplied often contain viruses. Some of these counterfeit cables do work with Nokia PC Suite but they require a special driver known as the "USB Serial C" cable driver which is almost impossible to find."

[Tommy Tyler]

Yesterday I received three CA-42 data cables. I'm 95% sure they are from the order with eBay store topvshow, but there was absolutely no way to prove that from anything on the padded shipping envelope. As expected they were in a one-piece molded enclosure rather than a snap-together enclosure. Everything looked identical externally to eferz's sample. Having seen how complex and expensive that design was, I became curious whether the guts of these could be as complex, for a price (with shipping) of only $2.78. Cutting open the outer boot showed a crude inner molding of black plastic, no shielding, and only three conductors in the cable. The PCB was about half the size of eferz's, with only five components not counting the USB connector. I'm getting more and more disillusioned and disgusted over this whole matter. Here's what it looks like:

The black wire is ground. I couldn't identify the red or white wires. The unit enumerates instantly as a Prolific Serial-to-USB Comm Port, but nothing I tried put any signals on either wire. Pin 5 may be Rx because it is extremely sensitive, and touching it with a meter lead floods the receiver with continual noise. I was also unable to see any voltage change on any of the unused solder pads by manipulating handshake signals with RealTerm.

What use could this particular design be to a Nokia cell phone, with just three wires? Maybe a battery charger? Now I'll go back and open up some of the other molded units I've accumulated and see if there are other surprises.

I'm trying to find out if DealExtreme will put me in direct contact with either of the two suppliers that "may" be selling only snap-open versions, but don't hold your breath. If I could even just learn which country they are in, that would narrow the search. How can there be so many little mon-and-pop garage operations in China that are capable of programming these allegedly counterfeit PL-2303 processors?

[Tommy Tyler]

Just a brief note that today's mail brought three 45715 data cables from the DealExtreme source and they were exactly like the one I used for my article. The return address on the mailing label was a Chinese name and address in Hong Kong. I'll search my records for someone in HK that may be a JP1 member and might track down that addressee for us.

[The Robman]

Just a brief note that today's mail brought three 45715 data cables from the DealExtreme source and they were exactly like the one I used for my article. The return address on the mailing label was a Chinese name and address in Hong Kong. I'll search my records for someone in HK that may be a JP1 member and might track down that addressee for us.

Are you saying that you ordered them from Deal Extreme but the actual package came from Hong Kong?

Btw, user smallstar is from Hong Kong.

[pH7_jp1]

Are you saying that you ordered them from Deal Extreme but the actual package came from Hong Kong?

Yes, the phone cables ordered from DealExtreme.com are shipped from Hong Kong. That is why I posted a source for the USB cable available from the USA at about the same price in this original thread started by Tommy. I had already ordered, but not received the phone cables when Tommy posted his process and didn't want to wait for that long again, just for a USB cable.

I assumed that since the phone cable came from Hong Kong, the USB from DealExteme would also. I guess that assumption could be wrong.

[Tommy Tyler]

My shipment of CA-42 cables from eBay store bigdigshop included this circuit board inside a 1-piece molded enclosure:

I guess there's no end to the number of different designs of these things. Meanwhile, eBay sellers yallstock and esaleseveryday appear from their ad pictures to be selling the good ones. One of these days I'll find out, wen my orders arrive.