Blinking green light, will not reset, black screen

Discussion in 'TiVo Series3 HDTV DVRs' started by BlaineMurphy, May 19, 2014.

  1. SirKnowsALot

    SirKnowsALot Member

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    Jun 3, 2015
    Kentucky
    Yeah, I will be (and have been) a little sporadic in looking at this. I just periodically post something to see if someone says something that might get me unstuck (like unitron's recent post). I'm a firm believer in group efforts, as I don't claim to be a wizard here.

    Hopefully I'll check out the S2 a little and find something interesting. Stay tuned...
     
  2. B1LL

    B1LL New Member

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    Aug 9, 2008
    Wow! Reading this thread is like reading a great mystery story.

    I found this thread today because my Tivo HD was stuck blinking green after a power failure. A hair dryer directed on U3003 fixed it, but when I power booted it a few times, it started blinking green again.

    Hat's off for the great detective work, but I was hoping this mystery story would have a great ending revealing how to nail this problem permanently.

    Anything new in the last 6 months?
     
  3. Apr 3, 2016 #143 of 258
    TiVoFGLOD

    TiVoFGLOD New Member

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    Apr 3, 2016
    This blinking green light just happened to my HD unit after a large windstorm disrupted power two times in rapid succession for a couple minutes last night. I replaced a few bulging caps on the power supply board but it made no improvement. Applying heat to the magic modem region caused the TiVo to go solid green! What would a power loss event do to make something more flaky when starting up? Is an oscillator problem? What could have been damaged but is still recoverable with a little heat? The unit has been running fine since 2009. What is the permanent fix that weaknees knows but won't disclose?!
     
  4. Apr 4, 2016 #144 of 258
    B1LL

    B1LL New Member

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    Aug 9, 2008
    Hair dryer heat anywhere on the MB seems to enable my unit to fully boot after an AC power cycle with the MB still warm. After the MB cools, it won't boot.

    It's as if the failure is a bad connection that doesn't cause the unit to stop running, but instead only blocks the FW from proceeding because a POST diagnostic or status check fails. This would be why it only shows up after a power failure. During a hung boot, heating the MB doesn't seem to enable the FW to proceed. The FW needs to go back to the beginning with a power cycle.

    I also tried some freeze spray in various places and more localized heat with a soldering iron and neither worked. I'm suspecting the problem may be a CPU surface-mount solder joint that needs to be re-flowed as some folks have theorized up-thread. However, it seems strange these units would work for so many years before a bad solder joint caused a problem.
     
  5. Apr 9, 2016 #145 of 258
    exraytheontom

    exraytheontom New Member

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    La Habra,...
    My Series 3 HD died yesterday after I unplugged it, took off the cover and blew out the dust. From what I have read, there isn't much hope for my DVR. Weakness said they could "probably" fix it with a motherboard and usual $99.99 dollar charge. I think my DVR is beyond economical repair. Unless someone else has come up with a fix. I checked the power supply and the voltages are: +3.3 OK, +5 OK and +12 at 11.78. I think I am done with it.
    Don't know if I want to spend $600 on a Roamio, not sure about the Bolt. I am open to suggestions. Thank you if you reply to this.
     
  6. AgbotHD

    AgbotHD New Member

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    Jan 23, 2016
    I appear to be seeing similar behavior. Blinking green, power down, heat U3003 area, now get successful boot. Allow U3003 area to cool, power down, back to blinking green.

    This is on my lifetime 652 that had the blinking green light issue fixed by WK a while back. A recent power failure killed it again (blinking green is back). Given the cost of another WK fix I begrudgingly took the plunge into a Bolt (which, overall I suppose I'm mostly happy with, but that's another thread).

    Has anyone taken a closer look at a WK repaired board? Maybe I'm seeing things on my previously repaired board, but I swear the solder pads on U3003 aren't as clean/smooth/symmetrical as any other SMD parts on my motherboard. I’m almost of the mind to replace the modem and see what happens. I'd attach the image but I'm not to 5 posts yet :) I forgot my original account details from many years back and re-registered again recently.

    Thoughts from anyone else? I think the Mouser/Digikey part is SI2434-D-FT.

    Another thought (and bear with me here, I’m a software guy that has muddled in hardware a little bit)… but has anyone scoped the 3.3V supply into the modem at power up? There are two VD3.3 pins. On a work related product we were dealing with an older GPS IC that very rarely upon cold boot would be unresponsive. It turned out that only one particular rev of that IC happened to be very sensitive to the ramp up to 3.3V.

    ----

    EDIT: I found some "before blinking green light repair" pictures I took before sending it to WK. Not as high res but the top markings on the modem itself appear to have the identical numbers (I'm not 100% given the lower res photos, but sure looks like it). Since this number includes the year and week of manufacture, it would be quite the luck of the draw if WK happened to replace my original part with one that was manufactured in the exact same year and week. So - maybe I got nothin' here. :(

    Maybe my next hair brained idea will be to use a different 3.3V supply for U3003. I've seen the opposite of what this "heat it up fix" is doing here on another project... where higher temps were causing a ripple in a 3.3V supply. Are higher temps around U3003 cleaning up the 3.3V supply? Is that even possible?
     

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    Last edited: Apr 10, 2016
  7. unitron

    unitron Well-Known Member

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    semi-coastal NC

    You're talking about a TCD652160, right?

    Was it showing any symptoms of anything being wrong before you opened it up?

    What are the symptoms now?

    Totally dead, no lights, no fan?

    Are you using the component or composite video output instead of HDMI to be sure that the problem isn't just the HDMI section?
     
  8. timhbtr53

    timhbtr53 Grumpy Old Man

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    Apr 24, 2014
    In the Deep...
    Have you been doing any work lately on "blinker" ?
     
  9. SirKnowsALot

    SirKnowsALot Member

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    Jun 3, 2015
    Kentucky
    Hey everyone, I'm glad to see some life again in this thread! I've been periodically checking in, but until just now it was a ghost town.

    Here's an update on my investigation. Don't get your hopes up, however.

    A few months back I could very reliably start my THD by warming up U3003. Cold=blink, Warm=boot.

    During the months that I've been away I obtained a hot-air SMD rework station and had planned to replace U3003 just because. Since so much time had elapsed since I last worked on it, I attempted to reproduce the Cold=blink/Warm=boot behavior before I tried changing anything. Much to my dismay, no matter what I did I could not get the THD to successfully boot. Now I'm at a loss for where to go next.

    Because there's new activity in this thread I will monitor more closely and be glad to listen and help where I can.
     
  10. SirKnowsALot

    SirKnowsALot Member

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    Jun 3, 2015
    Kentucky
    I'd love to see a WK reworked board up-close (or hi-rez photos).
    I believe that is the correct part. For me $40 in a new chip is a fairly big gamble. I don't want to discourage you though.;)
    We won't hold your background against you (plus that is my background as well)...
    Interesting comment on the 3.3v ramp-up. I did some scoping on the reset signal, but had some suspicions about power and never did anything about it.:p
    EDIT: Here's a trace from U3003, pin 21 (3.3v) on a successful boot. I got an almost identical trace from a blinking LED boot, so this may be ruled out.
     

    Attached Files:

    Last edited: May 12, 2016
  11. SirKnowsALot

    SirKnowsALot Member

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    Jun 3, 2015
    Kentucky
    EDIT: I just saw unitron's reply to your post, and wanted to be clear that only if you are having the blinking green LED problem would my procedure below be worth a try.

    Have you tried heating U3003 as described in my post here? It has allowed some folks to boot although it isn't a permanent fix. The only reason I used the light-bulb was to focus the heat in small areas so that I could pin down the chip that was causing the problem. Others have used the wife's hairdryer.

    If you can perform this procedure and report back as to what you found it would be helpful and may contribute to an eventual real fix for this.
     
    Last edited: May 12, 2016
  12. SirKnowsALot

    SirKnowsALot Member

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    Jun 3, 2015
    Kentucky
    I was able to probe around and while this doesn't resolve anything I want to at least put this in the record in case it helps down the road.

    I probed the RESET* signal on U3003 along with Vdd. I wanted to see what the reset looked like as power came up. Because the cursors on my trace blend in with the actual traces, I'll describe what is in the image below.

    CH1 is the 3.3v Vdd line. CH2 is the RESET* line. Both right on U3003. About 420ms after Vdd is applied RESET* goes to 3.3v. It stays at that level for about 965ms and then is pulsed low for around 750us. It is this 750us pulse that I believe is the actual reset to U3003.

    What I found was that when the boot was unsuccessful (i.e. blinking light), the RESET* pulse never comes. The question is why...and why does heating U3003 seem to make it work? That's what we need to work on.

    Note: I added some colored lines to the photo to differentiate between the signal traces and my cursor lines. I hope that helps.
     

    Attached Files:

  13. SirKnowsALot

    SirKnowsALot Member

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    Jun 3, 2015
    Kentucky
    One thing that I just could not get comfortable with is that why would warming up U3003 cause it to receive a RESET pulse, while a cold U3003 would not. This caused me to start doubting that I was actually seeing what I thought I saw. Maybe I wasn't warming up just U3003, but also some neighboring components. B1LL mentioned he could heat anywhere on the motherboard for a successful boot.

    With this in mind (and with some new equipment I recently acquired) I starting heating other areas surrounding U3003 while keeping U3003 itself cold. Long story short (well, less long) is that I think the main crystal, Y2201 is now the sensitive component. I heated it very precisely--good boot. I instantly cooled it with an air duster--blink. Repeat 2-3 times exactly the same.

    I wanted to probe the crystal with my scope, but the capacitance of the probe caused it to not oscillate at all and thus nothing happened. (At 54 MHz things get pretty touchy). So right now that's where we're at. I decided to post this unfinished work in case someone smarter than me can move us along faster. Any assistance is greatly appreciated! Also, if AgbotHD reads this before shelling out the money for a new U3003 that would make me happy as well.

    The attached photo shows the crystal in relation to the processor heatsink and our old friend U3003.
     

    Attached Files:

    Last edited: May 17, 2016
  14. unitron

    unitron Well-Known Member

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    I'd be tempted to re-solder that xtal, just to see if it made a difference.
     
  15. Jun 8, 2016 #155 of 258
    SirKnowsALot

    SirKnowsALot Member

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    Jun 3, 2015
    Kentucky
    I wanted to post a quick update on this investigation. Don't know if anyone (besides unitron) is still following the saga since it's been pretty quiet around here.

    Resoldering the crystal did not help. However, I swapped the crystal out of another THD that has a different problem and after making sure the crystal was cool, it powered right up and has been working fine. I've been too busy to try to unplug it for a few hours at a time and try a cold start, but when I get the time I will do that.

    Additionally, when I have time I want to put the "bad" crystal on the other Tivo and see if it catches the "blinking green" disease.

    One point of data doesn't prove much, but that's all we've got at this time.
     
    Last edited: Jun 8, 2016
  16. Jun 9, 2016 #156 of 258
    unitron

    unitron Well-Known Member

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    <artejohnsonvoice > "Verrrry Interesting". < /voice>
     
  17. Jun 9, 2016 #157 of 258
    telecomjd

    telecomjd New Member

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    Nov 10, 2013

    I'm closely following your progress and I appreciate your efforts to date because I'm having the same blinking green light problem. However, unlike what some have observed, heating the board with a blow dryer does not eliminate the blinking. So, either my issue is due to a different cause or an additional one. I'm reluctant to abandon this Tivo because of the lifetime service I would be losing. If replacing the crystal would eliminate the problem, that would be a terrific discovery. Thanks again for your efforts.
     
  18. Jun 9, 2016 #158 of 258
    Lancep50

    Lancep50 New Member

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    Jan 20, 2016
    I 2nd that. So far, I have been able to start using a blow dryer, but the symptoms just started. Just not sure how long this methods will work. Thanks for your efforts!
     
  19. Jun 9, 2016 #159 of 258
    SirKnowsALot

    SirKnowsALot Member

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    Jun 3, 2015
    Kentucky
    There may only be a few of us that get this reference...:p
     
  20. SirKnowsALot

    SirKnowsALot Member

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    Jun 3, 2015
    Kentucky
    I put the crystal from the blinking LED unit into the Tivo that donated the replacement crystal and that unit doesn't even get to the blinking stage. The LEDs all flash on when power is first applied, but then nothing at all.

    Either I ruined the crystal during the removal process or something is wrong with that particular crystal (that was originally in the blinking LED unit).

    I'll try to get some new crystals and see if that tells us anything. May be a while though...
     

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