Series 3 console cable

[NillaZilla]

There seems to be a few comments here and there concerning the console serial connection on the Tivo Series 3 units. I would like to collect that information here and describe making such a cable for reference. Thanks to all whom have contributed to finding this out.

The Tivo Series 3 has a 3-pin fan-style header near the corner of the motherboard close to the S-Video Out and Digital Audio Out ports.

http://media.twango.com/m1/original/0036/cb4d433426904bdeb77940129f2c8a21.gif

The older style DB9 (9-pin) to 1/8-inch stereo jack serial cable obviously doesn't fit, so we need an adapter.

Items needed:

3-pin molex "computer fan" style connector (female) (with wires)
Stereo 1/8-inch (3.5mm) headphone jack (female) e.g. Radio Shack cat.# 274-274
regular Tivo serial console cable (DB9 to stereo jack)
solder and soldering iron


http://media.twango.com/m1/original/0036/418238777d9948fb9d4c1a92272b0dc0.gif
http://media.twango.com/m1/original/0036/9a655273c22f4b50a65964a979e75d4a.gif

On the S3 board you'll notice the three pins are labelled: Rx G Tx, Receive, Ground, and Transmit, respectively. Wire up the stereo jack to the molex wires as shown (hopefully this will show mono-spaced):


Tivo S3 console cable adapter
1/8-inch stereo jack (female) 3-pin molex (female)

/---------------------o (RX) receive
/tip
ground (G) o----------------\
(collar) ring\ |
| \--------------------------o (TX) transmit |
| |
\-------------------------------------------------------/


Now you have a finished adapter cable.

http://media.twango.com/m1/original/0036/28fae7e8ebfb402da04f88d747fc3a62.gif

Attach the molex connector to the tivo motherboard, and now you can plugin a regular Tivo serial console cable.

The S3 has console output on TTY1.

[NillaZilla]

So you build the cable, and don't get console response from the Tivo S3? Here are some things to check:

Verify the Transmit (TX) and Receive (RX) pinouts on the 3-pin molex connector. Ground is the middle pin, and should attach to the collar of the stereo jack. To fix you can use a stiff paperclip (unbent) or a small jeweller's style flathead screwdriver to push down the catch on each pin and pull out the wire. Then re-insert the wires in the correct holes on the plastic molex piece.

http://media.twango.com/m1/original/0036/8d0fd376ddde4ca4a510376a8c9a3d6c.gif

Make sure you have your terminal software set to 115200 bps speed.
Make sure you have the correct COM port on your PC.

For console logs and whatnot from the Tivo, make sure you have the hard drive bootpage settings for console response:
dsscon=true console=1,115200

For serial bash on a hacked unit, you need at least the following in your /etc/rc.d/rc.sysinit or rc.sysinit.author file:

/bin/bash < /dev/ttyS1 &> /dev/ttyS1 &

Remember, like the Series-2.5 (nightlight) units the Tivo S3 has console on /dev/ttyS1.

[MacHack]

So you build the cable, and don't get console response from the Tivo S3?

Could you provide an example of the serial console output you get on a unmodified S3?

Thanks!

[Jamie]

Could you provide an example of the serial console output you get on a unmodified S3?

Thanks!

http://www.dealdatabase.com/forum/showthread.php?p=263808#post263808

You may have to set the bootpage console options before you'll get any output.

[mr_zorg]

Is anyone aware of a USB version of the serial cable for those of us with legacy-free PCs/Macs? If not, will a serial-to-usb adapter work for this?

[Jamie]

Is anyone aware of a USB version of the serial cable for those of us with legacy-free PCs/Macs? If not, will a serial-to-usb adapter work for this?yeah, you just need a usb-to-serial adapter for the PC/Mac.

[Omikron]

As a heads up, it would appear that at best, the diagram for making the cable is vague, and at worst incorrect.

To clarify, make sure that the tip is connected what what is labeled as TX on the mainboard, and the ring should ultimately be connected to what is labeled RX on the mainboard. I hope this helps some people.

Edit: Looks like my own post also needs clarification. ;-) NillaZilla's instructions are correct if you are using the OEM TiVo Serial cable, but are backwards if you are using a "Null Modem" cable, as I was...

[lrhorer]

Why don't we make this a little simpler? Add to the list of items needed one volt-ohm meter. No one should ever take a soldering iron into their hands unless the have a voltmeter at their elbow. Digital or analog will be fine, and the $15 pocket multimeter available at the corner hardware store will work as well as anything for this purpose.

Virtually all RS-232 ports on PCs these days are 9 pin male. If you have something else, you'll have to look up the pinout in your computer's user's manual. On the DB-9 connector, pin 2 is Rx, pin 3 is Tx, and pin 5 is ground. No other pins are needed for this application. However they route through intermediate connectors, pin 2 on the computer's port must eventually connect to the Tx pin on the TiVo, pin 3 must connect to the Rx pin on the TiVo, and pin 5 on the computer's port must connect to ground pin on the TiVo. If the external serial cable you are using is pre-manufactured, then test its pinout with the voltmeter set to Ohms to determine which pins go where on the cable you are making. Once done, check end-to-end to make certain you have continuity all the way, and test between each pin on the serial connector to make sure there are no shorts. End-to-end, the test should read zero ohms, and pin-to-pin it should read infinity.