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2017-06-19

Reading Philips TV logs with an USB-UART adapter

With my Philips TVs I never had the requirement to read the log, as they all had measurable faults or the Service Default Mode revealed everything I needed to know. In case of a two blinks error code, which points to the mainboard, or when the TV won't boot at all, it can be beneficial to peek into the log.

You need

  • An USB-UART Adapter. This device maps a serial  (UART) connection across USB to a serial port (COMx on Windows). Device drivers are required.
  • A terminal program, which can handle serial ports.

The hardware


There are various types of USB-UART adapters on the market (eBay or AliExpress). First I tried this type:

Those are garbage. They contain an illegal copy of a Prolific PL2303 Revision A chip, which is discontinued since 2012. Read HERE. The problem is that the latest Windows 8 & 10 driver won't work with it anymore. Some articles in the net say that Prolific has changed the device signature in their later revisions to lock out the copies. You need to install an older version of the driver. I wasted way too much time with this rubbish.

I opened mine up and the chip had no marking on it. Sure sign of a copy. Also, the USB plug already started to come off the board.

So I tried another one with the Silicon Laboratories CP2104 chip:


This one's legit. No driver problems, Windows found the driver itself and the device worked.

The software


On the PC you can use PuTTY. A more sophisticated program is RealTerm. It can record sessions, which is quite useful, and has more features than you'll ever need. Both are free.

The Android app Serial USB Terminal by Kai Morich also works fine. You can read the log on your tablet or phone quickly without a bulky laptop. Just put a micro USB adapter in front of the UART device.


The connection


Now this kept me busy for a while due to my own incompetence.

The UART / service socket on the TVs is a stereo 3.5inch type like for headphones. The connections are as follows:


Here is the rub: you need to cross RXD and TXD. Don't connect the RXD on the adapter with the RXD on the TV. Makes total sense once you understand it :-)

A schematic from a ComPair device manual put me on track:


And that's how I built the thing. I attached a 3.5 inch stereo socket to the adapter and used a stereo cable I had lying around:



First tests


I had a working 42PFL9803 sitting in my living room and I tested the device with it. To my surprise I could not get any useful log. The service manual says 38400bps 8N1. I configured everything accordingly and all I got was garbage. The TV sent data but it wasn't readable. I tried many bps setting with no luck. This TV fooled me for quite some time. I thought something was wrong with the UART adapter :-/

Yesterday, I picked up a 32PFL9606 and with this one it worked flawlessly. I don't know what's wrong with the 9803. Very strange.





Sweet! I can add one more diagnostic tool to my repertoire. I currently have a 46PFL8007 with the dreaded QFU chassis, which doesn't show any signs of life even though the standby voltage is good. It's not writing a log either. But that's the subject of an upcoming blog post once I have reprogrammed its boot EEPROM, which I suspect.

In the meantime, I glued it into a nice blue box:


22 comments:

  1. Well ,any progress on this subject?

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    1. Nope. The 8007 just won't wake up.

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  2. 42PFL9803 maybe really accepts rs232 levels like my old dvdr I got to read out using rs232 on board directly.

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    1. Yes, I also think it is a hardware issue. The 03 series ist just too old for this adapter. Well, for the dreaded QFU chassis it has proven to be very useful.

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  3. Did you try to flash the 256 byte spi ? I read some translated russian site where that provided to be the fix.

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    1. Yup! I fixed the sucker. Finding the right software was not easy though. I'll rewrite the post about the 46pfl8007 soon.

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  4. Did I just help you ? ;)
    I never picked up a qfu yet, but read about this SPI 256 byte issue that even the latest PUS range can have..

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    1. Sorry to disappoint you :-) Had the SPI reflashed weeks ago and due to a problem with a flat cable it had no image. I've rewritten my post and explained everything.

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  5. This comment has been removed by the author.

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  6. Looking forward to your post about programming the boot EEPROM.
    I've picked up an 'EZP2013' EEPROM programmer for 8 euros on e-bay, which clearly helped me to diagnose a faulty EEPROM of my 32PFL3606.

    I was wrong by thinking that an empty EEPROM would work, apparently I need to preload it as you mentioned.
    Now the TV is giving me a blinking red error and I haven't mastered the art of reading the error code yet. which is why I've ordered another SSB...
    thanks for your great articles

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  7. FOR THIS CHASSIS YOU CAN PRE ORDER ONLY MEDIATEK BASED SSB BECOSE THE PROBLEM WITH THIS MODELS IS A FAILING SIGMA FUSION CPU ;)

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  8. First of all, I need to say that the contents on this blog are awesome: well laid down and very informative. Thanks for your effort! :)
    I'm trying to troubleshoot a 46PFL7007K/12 (QFU1.1E LA) that doesn't turn on anymore. All the voltages are fine but I get the two blinks pattern from the led a while after the tv set is connected to the wall outlet. I've tried to put it in MDM mode and there I get the 53 pattern.
    According to what I've found around, it means software error. I've tried to connect a pendrive with the official update and plug the tv set in the wall outlet but unfortunately it didn't help. I didn't even exepct something to happen because I'm confident it isn't searching for the software update but something like a bootloader, something much more low level...
    Then I've thought I could understand something more by connecting a serial interface and I've built one thanks to your advices. I've tested on another Philips (a 37PFL9604H/12) and there it works perfectly fine (apart from the fact that at 38400bps I got only garbage and I was forced to put the port speed at 115200bps to get a readable output) but on the one I'm trying to troubleshoot I get NOTHING, nothing at all, garbage neither.
    The serial seems completely dead like everything else. Maybe I need to put the tv set in MDM mode to get something from the serial? It makes sense but I haven't had the chance to try.
    Thanks in advance for your advices and have a good day! :)

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    1. I was wondering... Should it be the bootloader, is it the M24C64-WDW6 to be reprogrammed? I'm taking a brief look to the service manual and it seems so or at least it seems the only eeprom on board but I can be mistaken about that: I've to find the time to look at it more carefully.

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    2. If there is no log at all, the boot program is corrupted. You can read all about this here: https://alpengeist-tvrepair.blogspot.com/2017/05/philips-46pfl8007-qfu11e-la-no-standby.html

      However, one thing is confusing me here. The error 52 is actually detected by the boot software according to the service manual. Therefore, you should see a log.

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    3. Hi and thanks for your reply! :) Thanks for pointing your other topic to me.
      The error is 53 but yours is certainly a typo... ;) Yours is exactly the same thought I've done and that's why I was wondering if entering SDM (not MDM, another typo this time by me!) was needed to get some output on the serial from a bricked tv set.
      I'll try to do it ASAP. Thanks again and have a good day! :)

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    4. The SDM only helps if the TV enters certain protection states or if you like to read out the level 2 error (here: the 53). It does not magically revive a bricked device which has a software problem. I think, in your case either the boot SPI Eeeprom or the NVRAM is broken. Or the processor broke some solder balls. You definitely need a infrared remote to continue the repair. A cheap copy for 10$ does the job here.

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    5. Hi and thanks for your advice. Please excuse me for not replying before but I couldn't.
      I've never thought SDM could help me with anyyhing more than pinpointing the kind of error, certainly not resolving anything. I think the processor is at fault otherwise I should get something on the serial interface though, as you, I'm puzzled about how a faulty CPU could produce even the blinking pattern...
      In the meantime, I've tried with another television (a Philips 37PFL6007K/12 which by what I've understood is almost the same family and with EXACTLY the same symptoms, 2 blinks in normal mode, 53 in SDM mode) but this time with the same setup and the same settings, I've got an output on the serial:

      95 00 unit:
      12:45:47.695
      12:45:47.701
      12:45:47.701 waiting ECC result ready
      12:45:47.701 00 bits error in the unit.
      12:45:47.701 01 unit:
      12:45:47.701
      12:45:47.708
      12:45:47.708 waiting ECC result ready
      12:45:47.708 00 bits error in the unit.
      12:45:47.708 02 unit:
      12:45:47.708
      12:45:47.714
      12:45:47.714 waiting ECC result ready
      12:45:47.714 00 bits error in the unit.
      12:45:47.714 03 unit:
      12:45:47.714
      12:45:47.720
      12:45:47.720 waiting ECC result ready
      12:45:47.720 00 bits error in the unit.
      12:45:47.720
      12:45:47.734 Hashed data:
      12:45:47.734 0xB5035438 42 4C 2B 00 26 48 C9 03 82 F2 0B 00 26 48 3E 01
      12:45:47.734 nand.c:nand_readwithinpage

      a similar pattern repeating a lot of times with only the memory addresses and unit # changing.
      I don't understand anything out of it. It seems something like an ECC error but I'm not certain about that. This time the serial talks at least, not a great deal cause I don't understand what it's saying! ;)
      What about the remote? Is there a post on your blog where you talk about it? I've read elsewhere about a Philips yellow remote (I may be mistaken) but I need to check again. Thanks for everything and have a good day!

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    6. About the remote: a simple IR does the job. You just need the OK or DOWN key. The original two-sided is useless when the TV doesn't boot up because the software for it is not loaded.

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    7. Hello again. I suppose the remote should work on the right frequency for the philips, not just any. By the way, I don't know what to do with OK and DOWN keys. I would need to inform myself.
      What about the serial output I've posted? Is a nonsense for you too or have you seen anything similar in the past?

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    8. I was wondering if the remote from the 37PFL9604H/12 could be useful... I think so because it should be a simple IR remote but I don't know...

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    9. Please see my latest Philips repair blogpost about the ok and down keys. The remote from the 04 series should fit.
      As for your log, I cannot see anything which helps with the diagnose.

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  9. This comment has been removed by the author.

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