1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Tivo HD Upgrade Instructions - using JMFS

Discussion in 'TiVo Upgrade Center' started by Tivoitis, Jan 4, 2011.

  1. unitron

    unitron Active Member

    16,389
    2
    Apr 28, 2006
    semi-coastal NC
    The orange wire (I think there's only one) should be +3.3V, the red wire(s) should be +5V, and the yellow wire(s) should be +12V, and the black wires are all ground, which is always supposed to read 0V relative to ground.

    You can wrap a couple of layers of paper towel around a hard drive and put it in the freezer overnight before doing something stressful to it.

    The paper towel keeps moisture from condensing on it when you bring it out of the freezer and as a bonus leaves all the skin on your hands instead of the drive case.
     
  2. Soapm

    Soapm Active Member

    1,564
    0
    May 9, 2007
    So close,...
    Is that called "freeze drive"...
     
  3. unitron

    unitron Active Member

    16,389
    2
    Apr 28, 2006
    semi-coastal NC
    :up::D
     
  4. BigJon

    BigJon New Member

    21
    0
    Mar 9, 2012
    Thanks unitron.....I'm having enough trouble without freezing my drive though :eek: Actually it is my drive that is freezing my Tivo :D

    Turns out the no-load voltages I was taking from the power supply weren't really telling me anything. So I made a probe that could get where it needed to go while stuck on an alligator clip and made voltage checks with the original 160 GB drive still in the unit (which ran overnight just fine - no rebooting). I got the expected voltages that unitron said I should get from the approtiate colored wires. I was able to check the yellow and red leads for the power cable to the HDD as well (under no load however) and they showed 5.1 vdc and 7.1 vdc respectively.

    I put the Hitachi 1 TB drive back in and it has been running all afternoon (in excess of four hours) without any reboots - unfortunately, the cable card issue that came up with sticking the original 160 GB HDD in goobered up my HBO channel settings that were on the Hitachi and even calling Comcast and getting the cable card paired again to authorize the movie channels did nothing for the Tivo to see them. All I managed to get from Comcast flashing the card was going from seeing the cable card screen whenever I tried to access a HBO channel to seeing a blank screen with the HBO logo in the upper right hand corner. Now, I 'm going to need to go get a new cable card before I try to do a JMFS transfer to a different 2 TB drive. I got my hands on a Hitachi HDS7230BLA642 locally and was going try the copy tonight, but now I'd be copying bad cable card pairing data over so I'll wait unitl I get that part fixed.

    Still leaves the question of what went wrong with the WD20EURS drive......of course I'm still assuming my PC/CPU did not pass anyting along during the JMFS copy that would have caused an issue (hence I really want to try a different drive and see what happens). With an Asus P5B, Intell dual core processor, and a JMicron Sata2 expander (used to connect my Thermaltake hot swap rack) I have a pretty low-tech but robust platform. I did have the 1 TB Hitachi in the hot swap bay during the JMFS copy - I doubt there was any issue there, it just recognizes drives in that bay as additional drives (it is not set up as a raid controller).

    I'll post again once I've fixed the cable card issue and have copied and expanded using the new Hitachi 2 TB drive instead this time.

    BJ
     
  5. unitron

    unitron Active Member

    16,389
    2
    Apr 28, 2006
    semi-coastal NC
    The yellow wire that runs to the hard drive and the yellow wire that runs to the plug that goes into the socket on the motherboard both connect to the same place on the power supply. There is only one +12V output section to the power supply, and the motherboard and the hard drive share it. No matter where you measure either yellow wire, you should get +12V referenced to ground (any of the black wires or the metal chassis itself).

    The red wire going to the hard drive is connected at the same place on the power supply as all of the other red wires.

    Same deal as the yellow wires, except this time it's the only +5V output on the power supply and any red wire should read +5V relative to ground.


    If you accidentally measured between the red wire and the yellow wire, the difference between +5 and +12 is +7. In other words, +12V is 7V more positive than +5V. Computer case modders sometimes do this on purpose to run 12V fans on 7V to make them slower and less noisy.

    But there's nothing in a TiVo that needs 7V.

    Trying to measure inside SATA power plugs is much trickier than the old 4 pin Molex sockets used on PATA/IDE drives.


    To measure TiVo voltages, clip the black lead to the chassis on the side away from the power supply and stick the red lead probe down into the individual holes of the back of the plug that goes into the socket on the motherboard.

    If you have steady hands and no alligator clip for the black lead probe, stick it into one of the holes with a black wire as far from the colored wire you wish to measure as possible to avoid accidentally shorting them together.

    All the black wires are tied together at the power supply where they are soldered to an area of copper that also extends to the screw holes on the power supply circuit board, so all of them and the metal chassis are at the same potential, electrically speaking.


    All of the red wires are joined electrically at the power supply circuit board and are therefore electrically identical.

    Same with the 2 yellow wires.
     
  6. BigJon

    BigJon New Member

    21
    0
    Mar 9, 2012
    Thanks once again unitron. The plot thickens, although it may be headed in a direction that unitron may have (am I putting words in your mouth? :eek:) suspected all along and that is the power supply; I had my first spontaneous reboot with the Hitachi 1 TB drive running in the unit, and it happened at a really rotten time - in the middle of guided setup as I was fixing the cable card issue from the problem I spoke of in an earlier post. The screen was stuck on the first "Welcome Powering Up" message and didn't move off of it. I cycled power after a 15 second delay, and it booted up normally, and I was able to finish guided setup. That was the only reboot so far this evening.

    The no-load voltage readings I received from the power supply connector that goes to the mother board continue to bother me in that I never saw a 12 volt reading; only after loading by plugging the power supply in and plugging the hard drive cable in did I get the 12 volt reading on the yellow cable using my improvised probe on the connector.

    I am not familiar with power supplies that regulate their voltage down when no load is sensed and I thought that there would be a constant voltage maintained despite current draw. Also, when I took the no-load voltage readings I could hear a capacitor discharging every half second or so (a rhythmic click-click-click-click-click, and so on). I just do not know enough about power supplies to nail if that capacitor discharging is a sure sign of trouble going on, or a normal operational mode for the large capacitor on the board.

    The no-load voltages were 3.3 vdc on the orange leads, 5.1 vdc on the red leads, and a varied (not study but bouncing) voltage of 6.5 - 7.1 vdc on the yellow lead.

    Does anyone have any similar result for a no-load voltage test? What about the capacitor discharge noise? I am going to postpone doing a JFMS copy onto the 2 TB Hitachi drive I picked up yesterday until I can get a better idea of whether the power supply is a prime suspect. If there should be a 12 vdc reading on the yellow lead regardless of load, then if I could be pointed to a member that sells refurbed or new power supplies, that would be great - - I am going to be heading out of town in a week and a half and I would like to get this issue resolved so that I've got both capacity and a functional Tivo to record in my absence.

    Thanks to everyone who has followed this weird path. If we were all to conclude "it was the power supply that done it", I think we could also surmise for whatever reasons, the Hitachi drive was less susceptible to the culprit than the WD20EURS was.

    BJ
     
  7. unitron

    unitron Active Member

    16,389
    2
    Apr 28, 2006
    semi-coastal NC
    With switching supplies, you can't assume lack of output in an unloaded condition means the same thing it does in the old style big heavy transformer before the AC is turned into DC type supplies.

    I would measure TiVo PS voltages only with either the motherboard connected, or the hard drive connected, if not both.

    In your case, I'd recommend hooking up the motherboard, clipping the meter's ground lead to the chassis on the side away from the power supply, sticking the red meter lead's metal probe tip down into the hole in the mobo plug into which the yellow wire goes, so that it's wedged against the metal end of the wire, then plug in the TiVo (have the cord already in the back of the TiVo, do the plugging and unplugging at the wall socket), and see what reading you get (already have the meter set on the right range).

    It should read +12V, or right close.

    Then plug the combo data/power lead into the hard drive and see how much change, if any, there is in the reading. It should stay steady.

    Then unplug stuff and do it again, only this time start by measuring one of the red wires at the motherboard, which should read right around +5V, and then add the drive again, and see if the reading holds steady.
     
  8. BigJon

    BigJon New Member

    21
    0
    Mar 9, 2012
    Thanks unitron. I did have two more spontaneous reboots with the 1 TB Hitachi; once in the middle of the night when I was up, I happened to check it and found it was stuck on the first "Welcome Powering Up" screen. I recycled power with the 15 second delay and it booted up normally. This morning I found it stuck on the first powering up screen again. FWIW, these symptoms were not present before I started down the JMFS upgrade path; as I mentioned in my earliest posts, the only aging issue with this drive was an occasional freeze frame of a few seconds or a few seconds of stutter framing.

    The voltage tests revealed no change on the red leads; at the mobo plug (with the PS plugged into the MB) during power-up, before hard drive connection, and after the hard drive combo data/power plug was snapped on, I got a consistent + 4.9 vdc at the mobo plug lead and the hard drive power lead.

    A little bit different story on the yellow lead. With the mobo plug connected to the MB and the hard drive disconnected, I got a + 12.4 vdc reading at the mobo plug lead as well as the yellow lead on the hard drive connector. With my Fluke meter's probe lodged in the mobo plug's yellow lead slot as you suggested, the moment I snapped the hard drive connector on, the voltage dropped to 11.4 and swung between 11.4 and 11.8 during boot- up. The further into boot the drive progressed, the closer to + 12.0 vdc the reading got. It stabilized at + 12.1 vdc.

    This time I did notice the cooling fan spun down. It did not spin all the way down to a halt, but it spun down to the point where it was not drawing much air.....I would have to say the cooling efficiency would have sucked. In fact, I probably mistook the cooling fan spin-down as disc spin down when I reported hearing the same on the WD20EURS in an earlier post.

    So, do the voltage fluctuations suggest the power supply? Does the fact that we seem to be stuck at either the GSOD (when the WD20EURS was doing its reboot loops) or the first power-up screen mean the MB is dying? I really hope we can find the answer soon (and without putting my 160 GB drive back in as I would hate to go through the cable card fiasco with Comcast again). Or could it possibly be as simple as the cooling fan spinning down and everything overheating as David M mentioned a few posts back??

    Really do appreciate the group's help here.

    Thanks,

    BJ
     
  9. unitron

    unitron Active Member

    16,389
    2
    Apr 28, 2006
    semi-coastal NC
    You can't really make any assumptions based on what the fan does when the cover is off.

    The fan's speed is controlled by the motherboard based on a temperature sensor on the motherboard.

    That fluctuation in the 12 V line is probably at the outside edge of the allowable variation while remaining in spec.

    Measure the 12V line again, this time with drive attached, plug TiVo into wall socket while watching meter, and see what happens.

    When the drive first spins up is when it would draw the most current and pull down the voltage the most, but the power supply is supposed to be able to keep the voltage fairly steady in the face of current demand changes.

    You might want to take the power supply out (watch out for the little screw that goes through the back panel from the outside into the top of the AC input socket, needs a #8 or #9 Torx), and looking at where the yellow wires enter it, turn it over and look at that particular area of copper, and then find the capacitor or capacitors whose + lead connects to that and whose - lead connects to the copper area which the black wires connect to and which also are where the screw holes are, that's ground.

    Even if that cap or those caps don't look bad, consider going ahead and replacing it or them.

    And examine all of the other caps very closely as well.

    Check out the picture here

    http://www.tivocommunity.com/tivo-vb/showthread.php?t=479176

    for how subtle the visual clues can be.
     
  10. BigJon

    BigJon New Member

    21
    0
    Mar 9, 2012
    OK, if I understood unitron's directions, I started this time with the Fluke meter's probe lodged in the power supply mother board connector's yellow lead, and then cycled power on; voltage reads are as follows, all + volts dc: 12.3 for less than a second, then immediately dropping to 11.3-11.5 for first minute of boot; 11.5 -11-8 for second minute of boot; 11.8 for third minute of boot; 11-8 12.2 after boot complete and voltage stabilized at 12.2 this time.

    I've got some programming I'm trying to record tonight. I will take the power supply out tomorrow morning and inspect the solder connections and also really scrutinize the capacitors - - I wasn't looking for chubby guys, I thought the ones with split tops and oozing innards were the signs of DOA....apparently there are some subtle signs of impending doom as those photos show.

    Replacing the caps will take me back to my Heathkit building days :D too bad you have to have crappy consumer electronics to get the good old Heathkit experience any more. In terms of expediency, would it be wise to put in a new/refurb power supply? I could always do the cap replacement and hang on to this one as a back-up. It seemed to me I saw a link somewhere in one of the forums for replacement power supplies - - anybody got any ideas?

    Thanks again for the help. I'll report back on the capacitor inspection when complete. Any comments on the voltages I reported in this latest test would be appreciated as well.

    BJ
     
  11. unitron

    unitron Active Member

    16,389
    2
    Apr 28, 2006
    semi-coastal NC
    Do you want to spend $10 or $100?

    You can buy another supply from Weaknees, or possibly on eBay.

    The 652s apparently had two different power supply designs at different times, so you might not be able to swap parts between them, although either should work with any 652 motherboard, and apparently both are possible capacitor disease candidates.
     
  12. unitron

    unitron Active Member

    16,389
    2
    Apr 28, 2006
    semi-coastal NC
    That fluctuation in the 12V line may be normal and within specs, but I can't be sure.

    I'm afraid I'm going to have to open up my 652 and do some tests and I really would just as soon not.
     
  13. Soapm

    Soapm Active Member

    1,564
    0
    May 9, 2007
    So close,...
    Just curious Bigjon, you don't happen to have a linux box do you? If you do I would suggest pulling the drive and reading the logs before you spend any money. You can also post the logs here and let some of the eyes take a peek. Also, if you have the original drive you might want to put it in and see what it does. You say the 1TB was freeze framing so maybe it just got sicker. But then that wouldn't explain why two drives have the same symptom.

    I put a 2TB in my THD and it starting rebooting every 20 minutes. Then it started doing it with my 1TB drive. I put the stock drive back in for a month and no problem.

    I've now had the 2TB in for about a month and no reboots. I'm hoping yours just starts working like mine...

    Edited to add...

    Also bigjon, can you post a new partition map of the upgraded drive? I ask because it dawned on me that jmfs leaves a little empty space at the end of the drive and if it did this with you then you have 17 partitions. I say this because the map you posted above from your upgraded 1TB has 15 partitions so if jmfs left that space you have 17 which might be your problem. Your tivo thinks it has an external drive. Look at my partition 14, that is that little extra space it leaves.

    Code:
    Partition map (with 512 byte blocks) on '/dev/hda'
     #:                type name                         length   base       ( size )
     1: Apple_partition_map Apple                            63 @ 1          (  31.5K)
     2:               Image Bootstrap 1                       1 @ 309549120
     3:               Image Kernel 1                       8192 @ 309549121  (   4.0M)
     4:                Ext2 Root 1                       524288 @ 309557313  ( 256.0M)
     5:               Image Bootstrap 2                       1 @ 310081601
     6:               Image Kernel 2                       8192 @ 310081602  (   4.0M)
     7:                Ext2 Root 2                       524288 @ 310089794  ( 256.0M)
     8:                Swap Linux swap                   262144 @ 310614082  ( 128.0M)
     9:                Ext2 /var                         524288 @ 310876226  ( 256.0M)
    10:                 MFS MFS application region       589824 @ 311400514  ( 288.0M)
    11:                 MFS MFS media region          137629696 @ 171919424  (  65.6G)
    12:                 MFS MFS application region 2     589824 @ 311990338  ( 288.0M)
    13:                 MFS MFS media region 2        171919360 @ 64         (  81.9G)
    [B]14:          Apple_Free Extra                          1645 @ 312580162  ( 822.5K)[/B]
    15:                 MFS MFS media region 3       3594447361 @ 312581807  (   1.6T)
     
  14. unitron

    unitron Active Member

    16,389
    2
    Apr 28, 2006
    semi-coastal NC
    jmfs does not leave space. Not unless you do something to screw up how it normally works.

    It copies byte for byte the source drive to the target drive (which means there will only be an Apple Free Partition if there already was one on the source, but since it was designed to work with original TiVo drives, there isn't supposed to be one), and if the target drive is larger than the source drive, which is pretty much the whole idea, it uses all of that extra space in which to create a single MFS Media partition and does some other voodoo to make the TiVo like it.

    MFS Live has been known to leave a little extra space when copying to a larger drive and adding an MFS pair, but apparently WinMFS avoids this.

    BigJon used WinMFS to copy his 160GB original to a 1TB and expand by adding an MFS pair, so only 15 partitions and no extra space, making him a perfect candidate for jmfs, provided there's nothing else wrong with the TiVo or the underlying physical part of the hard drive(s).

    As I recall, you were trying something with a 658 image to go on a 652, so there's no telling what you may have wound up with.

    Unless I've confused you with another TCF'er with whom I've discussed the whole partition 17 danger. After a while it all starts to run together.
     
  15. Soapm

    Soapm Active Member

    1,564
    0
    May 9, 2007
    So close,...
    If you look at my partition map I upgraded strait from the stock drive to the 2TB using jmfs and I have the extra partition. If you look closely I have a single partition that is 1.6tb in size. I know of only one way to get that and it's jmfs. All other upgrade tools that I know of adds partition pairs.

    Its true I tried a lot of things but none of that has anything to do with the partition map I posted. I wouldn't put that kind of confusion into another persons call for help. I don't know if its fair to call my integrity or motives into question.

    What I posted is from the stock 160gb drive that I ran for about a month reboot free so I used jmfs to upgrade it directly to 2tb and let it go about 3 weeks before hacking by hand which was a couple of weeks ago. The only thing not stock about this drive is the kernel, bash, iptables, busybox and tivowebplus.

    My curiosity can be alleviated by bigjon posting a partition map of his upgraded drive. Its sure a lot easier than replacing a power supply.
     
  16. unitron

    unitron Active Member

    16,389
    2
    Apr 28, 2006
    semi-coastal NC
    I'll explain better tonight. After sleep.
     
  17. BigJon

    BigJon New Member

    21
    0
    Mar 9, 2012
    Here is the partition and zone map info for the WD20EUS (I grabbed it thinking someone might ask this very question) - there was no apple_free or 17th partition issue here. The Hitachi 1TB had 15 partitions and I believe the 16th partition is standard JMFS practice for the enlarged storage capacity.

    (BTW - while I post the WD20EURS data and run out to find a Torx driver small enough to remove the screw holding the AC power input lug into place against the back of the Tivo; I don't have a Torx 5 it seems.....can anyone tell me which were the counterfeit caps, the one's with the gold labeling on black or silver labeling on black [I have the gold] - I don't see any budging yet but I want to take a closer look with the power supply out of the chassis).

    And no, I don't have a Linux box - - I am just now going through the process of installing Windows 7 Professional after running XP for 15 years. Closest I get to Linux are the MFSlive and JFMS boot discs.

    WD20EURS MFSInfo dump:

    Mfsinfo (Drive 5)

    Boot Page
    Boot Page: root=/dev/hda4
    Active Boot Partition: 3 Active Root Partition: 4
    Backup Boot Partition: 6 Backup Root Partition: 7

    MFS Super Header
    state=0 magic=ebbafeed
    devlist=/dev/hda10 /dev/hda11 /dev/hda12 /dev/hda13 /dev/hda14 /dev/hda15 /dev/hda16
    zonemap_ptr=1121 total_secs=3905175552

    Zone Maps
    Z0: type=0
    map_start=1121 map_size=1 backup_map_start=589822
    next_map_start=263266 next_map_size=6 next_backup_map_start=589816
    zone_first=1122 zone_last=263265 zone_size=262144 min(chunk)=262144
    free=262144 checksum=b6dc2f1c logstamp=7088989 num_bitmap=1
    Z1: type=2
    map_start=263266 map_size=6 backup_map_start=589816
    next_map_start=263272 next_map_size=34 next_backup_map_start=589782
    zone_first=589824 zone_last=138215423 zone_size=137625600 min(chunk)=20480
    free=17059840 checksum=d4c92fed logstamp=7089236 num_bitmap=14
    Z2: type=1
    map_start=263272 map_size=34 backup_map_start=589782
    next_map_start=138219520 next_map_size=1 next_backup_map_start=138809343
    zone_first=263306 zone_last=589777 zone_size=326472 min(chunk)=8
    free=43904 checksum=3fe53c07 logstamp=7089236 num_bitmap=17
    Z3: type=0
    map_start=138219520 map_size=1 backup_map_start=138809343
    next_map_start=138481665 next_map_size=10 next_backup_map_start=138809333
    zone_first=138219521 zone_last=138481664 zone_size=262144 min(chunk)=262144
    free=262144 checksum=9299c1dc logstamp=7088989 num_bitmap=1
    Z4: type=2
    map_start=138481665 map_size=10 backup_map_start=138809333
    next_map_start=138481675 next_map_size=34 next_backup_map_start=138809299
    zone_first=138809344 zone_last=310718463 zone_size=171909120 min(chunk)=20480
    free=21790720 checksum=f2934e5f logstamp=7089236 num_bitmap=15
    Z5: type=1
    map_start=138481675 map_size=34 backup_map_start=138809299
    next_map_start=310728704 next_map_size=67 next_backup_map_start=310730685
    zone_first=138481709 zone_last=138809292 zone_size=327584 min(chunk)=8
    free=302544 checksum=3fd21074 logstamp=7089033 num_bitmap=17
    Z6: type=2
    map_start=310728704 map_size=67 backup_map_start=310730685
    next_map_start=1951670272 next_map_size=66 next_backup_map_start=1951670338
    zone_first=310730752 zone_last=1951670271 zone_size=1640939520 min(chunk)=20480
    free=444456960 checksum=27f4c7ce logstamp=7089236 num_bitmap=18
    Z7: type=2
    map_start=1951670272 map_size=66 backup_map_start=1951670338
    next_map_start=0 next_map_size=0 next_backup_map_start=0
    zone_first=1951671296 zone_last=3905156095 zone_size=1953484800 min(chunk)=20480
    free=1952972800 checksum=f9241b6 logstamp=7088989 num_bitmap=18

    Partition Maps
    #: type name length base ( size )
    1 Apple_partition_map Apple 63@1 ( 31.5K)
    2 Image Bootstrap 1 1@309550766 ( 512.0 )
    3 Image Kernel 1 8192@309550767 ( 4.0M)
    4 Ext2 Root 1 524288@309558959 ( 256.0M)
    5 Image Bootstrap 2 1@310083247 ( 512.0 )
    6 Image Kernel 2 8192@310083248 ( 4.0M)
    7 Ext2 Root 2 524288@310091440 ( 256.0M)
    8 Swap Linux swap 262144@310615728 ( 128.0M)
    9 Ext2 /var 524288@310877872 ( 256.0M)
    10 MFS MFS application region 589824@311402160 ( 288.0M)
    11 MFS MFS media region 137630712@171920054 ( 65.6G)
    12 MFS MFS application region 2 589824@311991984 ( 288.0M)
    13 MFS MFS media region 2 171919990@64 ( 82.0G)
    14 MFS MFS App by Winmfs 2048@312581808 ( 1.0M)
    15 MFS MFS Media by Winmfs 1640939520@312583856 ( 782.5G)
    16 MFS MFS media region 3 1953505792@1953523376( 931.5G)

    Total SA SD Hours: 2083 Total DTV SD Hours: 1818 62 % Free
    Software: 11.0k-01-2-652 Tivo Model: TCD652160

    Hope this illumitnates something........I seem to be getting deeper into the dark.

    BJ
     
  18. BigJon

    BigJon New Member

    21
    0
    Mar 9, 2012
    I took the power supply out as unitron suggested. The solder connections on the underside of the board all looked good. What was perhaps suspect was one, possibly two of the 10 V 2200 uf capacitors had the first signs of bulging. Based on what I have seen in the threads on Tivo power supply deaths due to the capacitor plague (and that the reboot issue is common to all those with sick capacitors except for the ones that just grenade - then there are other things that don't work).

    So, I am going to pick up a kit of the capacitors I need to replace all of the small ones on the board and just put new ones in from a reliable source. I can probably get all the parts I need locally at Fry's that's in driving range.

    I'll report back once I've got the power supply buttoned back up and have a new image on the WD20EURS (I'll need to re-do the JMFS copy since there is new cable card data on the Hitachi 1 TB drive).

    Thanks for everyone's help.

    BJ
     
  19. unitron

    unitron Active Member

    16,389
    2
    Apr 28, 2006
    semi-coastal NC
    I'm quite sure you'd never willingly or knowingly attempt to de-rail someone else's attempt to get help here, and I sincerely hope we will not have a falling out about this. I apologize if anything I said made you feel I had accused you of anything untoward.

    That said, and wishing that comer still came around to answer questions, I feel almost certain that the Apple Free partition was already on your source drive before jmfs did any copying, and further, since comer probably didn't forsee any need for it, jmfs probably can't even create any kind of partition except for an MFS Media one.

    When you say stock 160GB drive, do you mean one that came in the TiVo from the factory and that was never re-imaged in any way?
     
  20. unitron

    unitron Active Member

    16,389
    2
    Apr 28, 2006
    semi-coastal NC
    Obviously those 10V caps aren't across the 12V line (unless there was a mistake made at the place where the power supply was made), so I'm guessing they're on the 5V one. It's a little odd, since the 5V line seems to be so much steadier than the 12.

    The reason for looking at the underside of the supply isn't to check how well things are soldered, it's to see which things are soldered to which area of copper so as to figure out what's connected to what.

    For instance, the copper "land" to which the yellow wires are both connected should also have the + terminal of one or maybe two capacitors also sticking through from the other side and soldered in place. There should also be one end of a coil of what looks like bare wire (but it's actually insulated with a thin layer of varnish of some sort).

    The - lead of that capacitor or those capacitors should be sticking through a different copper land, one to which all of the black wires are connected. That's ground.

    That's how you identify which cap or caps is/are across the +12V output.

    The same technique will work for the +5V output, just start with where all the red wires go through the power supply circuit board and work your way back.

    Find the cap or caps connected to the 12V line and ground, and the cap or caps connected to the 5V line and ground, and replace those and if the problem is just the power supply, that should do it, and if not then you'll most likely have headed off any future power supply problem.

    You want radial (not axial) low ESR caps rated for 105 degrees (celsius), the same uF rating as what you're replacing, and the voltage rating needs to exceed the voltage of the section in which they'll be put. (If by some chance those 10V caps were actually installed on the 12V line instead of the 5, replace them with 16V or 25V ones, depending on what's available).

    Radial means both leads come out the bottom. Axial is a type that's more of a tube with one lead comng out of each end.

    Make yourself a diagram of what's where, and remember that the replacement caps have to physically fit where the old one's did, so take note of the height and diameter, and how much room is available.

    An available replacement may be shorter and wider or taller and skinnier while still being the same uF, Voltage, Temp, and ESR rating.

    (Equivalent Series Resistance, in case you wondered)
     

Share This Page