Announcement

Collapse
No announcement yet.

TNPA5105 rebuild

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    TNPA5105 rebuild

    Well, i purchased this since it was rare and cheap. Was meant to be Used - working from smashed screen. Sounds about right because it's shorted.

    Bugger. looks like I have a board to fix

    Anyway just gone over it with everything still fitted (minus an inductor torn off in transit)

    SC2 - is not shorted
    P5V resistance = 5.63K which is normal
    TP82(P15V) resistance = 440 ohms bad

    Straight away we know IC521 is no good as the 15Vin is supplied to IC521

    These show short in cct but some will clear as i work through this.

    Q660 R5007ANX
    Q661 RJP63F4A
    Q421 RJP43F4A
    Q422 RJP43F4A
    Q401 DG502LW
    Q402 DG502LW
    Q451 45G128
    Q551 CPH5524
    Q521 CPH5524

    D422 RFUS20T4S
    D401 F50ALW
    D402 F50ALW
    D482 RFUS20T4S
    D503 D1FK60
    D673 D1FK60
    D674 D1FK60
    D451 RF071L4S

    IC521 M81737FP
    IC501 M81737FP MAYBE

    Q701,702,818 seem ok
    IC773 TC7SH14F seems ok
    IC771 TA78L05 seems ok
    IC724 78M05 ok
    R521,522 ok
    gate resistors ok

    remove IC521

    TP82(P15V) = 1330 ohms normal
    Q521 now in meg ohms , normal
    Q551 stiil low

    Remove Q451, shorted
    Remove D482, shorted
    D451 now ok
    Q551 still short

    Q551 removed, shorted

    Q661 removed, shorted
    Q660 removed, shorted

    D673,674, 503 now cleared ok

    to be continued...........
    Last edited by tw2005; 04-20-2015, 06:51 AM.

    #2
    Re: TNPA5105 rebuild

    Originally posted by tw2005 View Post
    well, i purchased this since it was rare and cheap. Was meant to be used - working from smashed screen. Sounds about right because it's shorted.

    Bugger. Looks like i have a board to fix

    Anyway just gone over it with everything still fitted (minus an inductor torn off in transit)

    sc2 - is not shorted
    p5v resistance = 5.63k which is normal
    tp82(p15v) resistance = 440 ohms bad

    straight away we know ic521 is no good as the 15vin is supplied to ic521

    these show short in cct but some will clear as i work through this.

    Q660 r5007anx
    q661 rjp63f4a
    q421 rjp43f4a
    q422 rjp43f4a
    q401 dg502lw
    q402 dg502lw
    q451 45g128
    q551 cph5524
    q521 cph5524

    d422 rfus20t4s
    d401 f50alw
    d402 f50alw
    d482 rfus20t4s
    d503 d1fk60
    d673 d1fk60
    d674 d1fk60
    d451 rf071l4s

    ic521 m81737fp
    ic501 m81737fp maybe

    q701,702,818 seem ok
    ic773 tc7sh14f seems ok
    ic771 ta78l05 seems ok
    ic724 78m05 ok
    r521,522 ok
    gate resistors ok

    remove ic521

    tp82(p15v) = 1330 ohms normal
    q521 now in meg ohms , normal
    q551 stiil low

    remove q451, shorted
    remove d482, shorted
    d451 now ok
    q551 still short

    q551 removed, shorted

    q661 removed, shorted
    q660 removed, shorted

    d673,674, 503 now cleared ok

    to be continued...........

    q660 r5007anx
    q661 rjp63f4a
    q421 rjp43f4a
    q422 rjp43f4a
    q401 dg502lw
    q402 dg502lw
    q451 45g128
    q551 cph5524

    q521 cph5524

    d422 rfus20t4s
    d401 f50alw
    d402 f50alw


    d482 rfus20t4s

    d503 d1fk60
    d673 d1fk60
    d674 d1fk60
    d451 rf071l4s


    ic521 m81737fp

    Will most likely replace IC773, Q701,702,818 just in case but not showing the traditional signs of shorts
    Last edited by tw2005; 04-21-2015, 05:07 AM.

    Comment


      #3
      Re: TNPA5105 rebuild

      Hi all. This is my first message on the forum. First of all, let me thank you guys for useful advice, especially in TNPA5081 rebuild thread (my broken SC board was TNPA5105, so I write it into this thread). It helped me a lot and I also want to share my "repair story", perhaps it can help others too.

      So, a week ago, my Panasonic TX-P50U20E suddenly went dead with a silent *pop*, giving me the 10 blink code afterwards. After looking at the manual, I thought - P board. Disassembled, no obvious signs of damage anywhere. But found dead short on SC2 connector. My SC board is TNPA5105 AB TXNSC11FEK50. First I thought, board swap, but when I saw the price - cheapest 143 $, with waiting time 15-60 days from Aliexpress - I decided to try and repair it myself.

      I replaced the following parts:
      Q661 RJP63F3A shorted
      Q660 RJK6026 shorted
      Q401 DG502LW shorted
      Q621 RJP3034 shorted
      Q451 45G128 shorted
      D482 RFUS20 shorted
      R551 D0GD100JA059 10 OHM 0.25W blown open (fluctuating around 47 kohms)
      Q551 B1HFPFA00001 shorted
      R451 D0GF5R6JA047 5.6 OHM 0.33W showing 7 ohm

      Following parts were put back when measuring after removal:
      Q402 DG502LW shorted, but found OK after removal (parallel to Q401)
      Q521 B1HFPFA00001 removed but later found OK
      IC521 C0ZBZ0001708 M81737FP removed but later found OK

      I replaced those in the list from local supplier here in Slovakia (luckily they have some Panasonic parts, but not all, I had to find substitutes, as I didn't want to wait for shipment from somewhere half a world away).

      Substitutes:
      Q661 RJP63F4A instead of RJP63F3A
      Q451 DG402RP instead of 45G128
      Q621 30F125 instead of RJP3034
      R551 and R451 I used normal axial carbon 0.33W resistors as I had them on hand

      After the refit, I measured the resistance on SC20 pins again. Showed something like 5kohms, so I thought, let's try to power it up. Too bad I found this forum only after I did that . I only heard moderate *ssss* sound, and got 7 blink code. On SC board, Q661 blown again (shorted). When I found the TNPA5081 rebuild thread, and measured the resistances on SU and SD boards, I found out that they are shorted too.

      SD: VFO / VFG 1 ohm bad, VSCN_F / VFG 220 kohm ok, 5V_F / VFG 5 ohm bad
      SU: VFO / VFG 1 ohm bad, VSCN_F / VFG 220 kohm ok, 5V_F / VFG 5.7 Mohm ok

      I'm not sure if that happened as a consequence of bogus SC, or if they were the reason the SC failed in the first place. Panel doesn't appear to be cracked, so I'm gonna go with the former.

      So I ordered new SU and SD boards, luckily they are not too expensive - 15 eur each, ordered from Czech republic. Following the forum thread, I patiently went through all the parts which mostly fail.

      Q661 was shorted again, replaced again with RJP63F4A
      Q701 B1ADCN000007 shorted, replaced with original
      Q702 B1ABCF000231 shorted, this one I substituted with BC846B
      IC773 C0JBAB000715 shorted, replaced with original
      D652 B0ECKP000055 shorted, replaced with MUR160 in DO41 package

      D652 was a bit weird, as I didn't find it in any of the SC rebuild threads. Therefore, while waiting for SU/SD boards, I decided to go through the SC really thoroughly, investigating complete ccts where something failed. I used schematics from TX-P50U20B manual, which also has chassis GPF13DE, but is more closer in design of the SC board to my board than P46U20E manual. One thing which kept bothering me was 500 ohm slowly rising to 1.74 kohm resistance on 16V_F to VAD, which seemed a bit low to me. But basically, when Q702 opens, there is only 1 kohm path via R712 to VAD. And I also didn't find any problem in parts involved in 16V_F line (I test-removed IC920, IC661, IC771 and IC501, 16V_F to VAD still 1.74 kohms), so I left it like that.

      Finally, today, after a week, I tested the SC board again. With SC50 shorted with a croco (jumpers I have are too wide to fit), SC20 ribbon connected, and SU SD removed completely, it powered up successfully!

      So, tomorrow when new buffer boards arrive, I will try again. Fingers crossed...

      Comment


        #4
        Re: TNPA5105 rebuild

        Slightly off-topic, but seeing the RJP63F4A reminded me of recently fixing the washing-machine....

        The machine, a Miele WT945 uses an IGBT to control the Motor. I replaced it with Yup--You guessed it--RJP63F4A!

        Works a treat!
        TELEFIX

        How PLASMA SCREENS WORK, X-SUS and Y-SUS what they do--
        http://www.irf.com/technical-info/appnotes/an-1088.pdf
        PLEASE DO NOT EMAIL ME PRIVATELY FOR REPAIR ADVICE. QUESTIONS BELONG ON THE FORUM!

        Comment


          #5
          Re: TNPA5105 rebuild

          Originally posted by Lucif View Post
          Hi all. This is my first message on the forum. First of all, let me thank you guys for useful advice, especially in TNPA5081 rebuild thread (my broken SC board was TNPA5105, so I write it into this thread). It helped me a lot and I also want to share my "repair story", perhaps it can help others too.

          So, a week ago, my Panasonic TX-P50U20E suddenly went dead with a silent *pop*, giving me the 10 blink code afterwards. After looking at the manual, I thought - P board. Disassembled, no obvious signs of damage anywhere. But found dead short on SC2 connector. My SC board is TNPA5105 AB TXNSC11FEK50. First I thought, board swap, but when I saw the price - cheapest 143 $, with waiting time 15-60 days from Aliexpress - I decided to try and repair it myself.

          I replaced the following parts:
          Q661 RJP63F3A shorted
          Q660 RJK6026 shorted
          Q401 DG502LW shorted
          Q621 RJP3034 shorted
          Q451 45G128 shorted
          D482 RFUS20 shorted
          R551 D0GD100JA059 10 OHM 0.25W blown open (fluctuating around 47 kohms)
          Q551 B1HFPFA00001 shorted
          R451 D0GF5R6JA047 5.6 OHM 0.33W showing 7 ohm

          Following parts were put back when measuring after removal:
          Q402 DG502LW shorted, but found OK after removal (parallel to Q401)
          Q521 B1HFPFA00001 removed but later found OK
          IC521 C0ZBZ0001708 M81737FP removed but later found OK

          I replaced those in the list from local supplier here in Slovakia (luckily they have some Panasonic parts, but not all, I had to find substitutes, as I didn't want to wait for shipment from somewhere half a world away).

          Substitutes:
          Q661 RJP63F4A instead of RJP63F3A
          Q451 DG402RP instead of 45G128
          Q621 30F125 instead of RJP3034
          R551 and R451 I used normal axial carbon 0.33W resistors as I had them on hand

          After the refit, I measured the resistance on SC20 pins again. Showed something like 5kohms, so I thought, let's try to power it up. Too bad I found this forum only after I did that . I only heard moderate *ssss* sound, and got 7 blink code. On SC board, Q661 blown again (shorted). When I found the TNPA5081 rebuild thread, and measured the resistances on SU and SD boards, I found out that they are shorted too.

          SD: VFO / VFG 1 ohm bad, VSCN_F / VFG 220 kohm ok, 5V_F / VFG 5 ohm bad
          SU: VFO / VFG 1 ohm bad, VSCN_F / VFG 220 kohm ok, 5V_F / VFG 5.7 Mohm ok

          I'm not sure if that happened as a consequence of bogus SC, or if they were the reason the SC failed in the first place. Panel doesn't appear to be cracked, so I'm gonna go with the former.

          So I ordered new SU and SD boards, luckily they are not too expensive - 15 eur each, ordered from Czech republic. Following the forum thread, I patiently went through all the parts which mostly fail.

          Q661 was shorted again, replaced again with RJP63F4A
          Q701 B1ADCN000007 shorted, replaced with original
          Q702 B1ABCF000231 shorted, this one I substituted with BC846B
          IC773 C0JBAB000715 shorted, replaced with original
          D652 B0ECKP000055 shorted, replaced with MUR160 in DO41 package

          D652 was a bit weird, as I didn't find it in any of the SC rebuild threads. Therefore, while waiting for SU/SD boards, I decided to go through the SC really thoroughly, investigating complete ccts where something failed. I used schematics from TX-P50U20B manual, which also has chassis GPF13DE, but is more closer in design of the SC board to my board than P46U20E manual. One thing which kept bothering me was 500 ohm slowly rising to 1.74 kohm resistance on 16V_F to VAD, which seemed a bit low to me. But basically, when Q702 opens, there is only 1 kohm path via R712 to VAD. And I also didn't find any problem in parts involved in 16V_F line (I test-removed IC920, IC661, IC771 and IC501, 16V_F to VAD still 1.74 kohms), so I left it like that.

          Finally, today, after a week, I tested the SC board again. With SC50 shorted with a croco (jumpers I have are too wide to fit), SC20 ribbon connected, and SU SD removed completely, it powered up successfully!

          So, tomorrow when new buffer boards arrive, I will try again. Fingers crossed...
          I have not touched mine since last post, mainly because the TV it suits is in another location which I'm moving back to next year. may get some interest in it then.

          I like you're creativity with the subs if this is first time at a rebuild. I've only just started looking for alternatives myself. When you look at the 5081 & 5105 you realise instead of chasing panasonic IGBTs you can use the RJP series because that's what they've done on the 5105.

          You would have found that diode had you searched using that part number. Not all locations match up between the 5081 & 5105 boards.

          Of course you'll be checking those buffers before install. I did the same thing early on playing with these, hard way to learn but the majority of the time they're ok in this series but I always check now.

          Those buffers will work in the upspec model too, they just don't have the heatsinks. yes they can be had cheap and I bought a few sets just because the others are getting rare and expensive.

          Do you plan to finish it off with the correct resistors? The originals are metal film so I'd expect them to have a smaller temp coefficient.

          Comment


            #6
            Re: TNPA5105 rebuild

            Hi Tw2005. Thank you - yes, my first rebuild. I did some small PCB prototyping but nothing the scale of those boards, not even close. Learned some new skills with desoldering and soldering those small "flea components" like IC920 without hot air station :-P.

            I think you are exactly right regarding those subs. The parts could be easily replaced, had the Panasonic actually publish their parameters. I think the secrecy is deliberate, as it is good for business ;-). I mostly got the idea about the specs roaming through the threads on this forum. Like that diode D652, the info that it's 400V 1A fast acting one is from you :-). Actually you were talking about D451, but it's the same one, thank you for that.

            The buffers arrived today, I quickly tested them, they were in Mohms except VSCN_F, which was 220kohm, as it should be. So assembled the sucker (omg, Panasonic, why 10 kinds of screws?), and it's now running for 1 hour, so I guess, I can call it a success. Those resistors are actually metal film, sorry for misinfo. So I guess they should be fine. We'll see..

            Comment


              #7
              Re: TNPA5105 rebuild

              Originally posted by Alastair E View Post
              Slightly off-topic, but seeing the RJP63F4A reminded me of recently fixing the washing-machine....

              The machine, a Miele WT945 uses an IGBT to control the Motor. I replaced it with Yup--You guessed it--RJP63F4A!

              Works a treat!
              Hmm, if that's a 360V IGBT it's cutting it kind of close for what is presumably a mains-powered motor controller, operating at a bus voltage of 320-360V...
              Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
              For service manual, schematic, boardview (board view), datasheet, cad - use our search.

              Comment


                #8
                Re: TNPA5105 rebuild

                Originally posted by tom66 View Post
                Hmm, if that's a 360V IGBT it's cutting it kind of close for what is presumably a mains-powered motor controller, operating at a bus voltage of 320-360V...
                Huh......?

                Renesas datasheet reckons 630V 40A.....?

                Original, some Motorola thing was 600V 15A....

                --Yup--Mains powered motor, Full-wave rec, no smoothing and IGBT connected to supply via a diode, then to motor via two relays....

                Looks like the controller uses high-frequency switching to control the motor, there's a fairly meaty inductor in series with it.
                TELEFIX

                How PLASMA SCREENS WORK, X-SUS and Y-SUS what they do--
                http://www.irf.com/technical-info/appnotes/an-1088.pdf
                PLEASE DO NOT EMAIL ME PRIVATELY FOR REPAIR ADVICE. QUESTIONS BELONG ON THE FORUM!

                Comment


                  #9
                  Re: TNPA5105 rebuild

                  So--With Two TNPA5105 and a TNPA5081 dead, thought I would start off with the 5105's.

                  Ive two sets, both 42" 720p using these. One came in a week ago, quickly found Q661 S/C so bunged the set in the To-it pile...

                  As I work in recycling-centre fixing sets, Ive the advantage of no screaming customers, I can scrap or fix whatever is appropriate...

                  The other set is an incomplete one that needs one of these 5105, a buffer and a PSU--Someone robbed it before I got hold of it, but near perfect condition....

                  This first board has the following issues, to save confusion I'll work on only one at a time--

                  Q451, S/C 45G128
                  D482 S/C RFUS20
                  Q521 23 ohm 3Y9L4
                  Q551 (dont trust) 3Y9L4
                  IC521 M18737 (Driver, suspect, cant test properly, will replace)
                  D422 s/c RFUS20
                  Q422 s/c RJP43F4A
                  Q421 s/c RJP43F4A
                  D402 s/c F50ALW
                  D401 s/c F50ALW
                  Q402 s/c D502LW
                  Q401 s/c D502LW
                  Q501 8.2 ohm 3Y9L4
                  IC501 M18737 suspect.
                  Q661 s/c RJP63F3A

                  IC771 78L05 O/P = 5K, I/P = 1.7K
                  Q818 reads odd but not s/c.
                  Q701 reads OK
                  Q702 reads OK
                  IC773 no apparent shorts

                  IC724 7805, reads ok, o/p 2.61K, I/P greater than 20M

                  All the above were checked on the board and nothing has been removed for further testing yet. I expect many of the above shorted parts will be found to be OK when the confirmed short components have been removed.

                  While I think of it, When testing out a board in the set with SC50 shorted, and buffers disconnected, is there any limit on time as to it being tested?
                  Could it say, be run for half hour before going further and fitting buffer etc....?
                  Last edited by Alastair E; 01-28-2016, 03:58 PM.
                  TELEFIX

                  How PLASMA SCREENS WORK, X-SUS and Y-SUS what they do--
                  http://www.irf.com/technical-info/appnotes/an-1088.pdf
                  PLEASE DO NOT EMAIL ME PRIVATELY FOR REPAIR ADVICE. QUESTIONS BELONG ON THE FORUM!

                  Comment


                    #10
                    Re: TNPA5105 rebuild

                    Originally posted by Alastair E View Post
                    So--With Two TNPA5105 and a TNPA5081 dead, thought I would start off with the 5105's.

                    Ive two sets, both 42" 720p using these. One came in a week ago, quickly found Q661 S/C so bunged the set in the To-it pile...

                    As I work in recycling-centre fixing sets, Ive the advantage of no screaming customers, I can scrap or fix whatever is appropriate...

                    The other set is an incomplete one that needs one of these 5105, a buffer and a PSU--Someone robbed it before I got hold of it, but near perfect condition....

                    This first board has the following issues, to save confusion I'll work on only one at a time--

                    Q451, S/C 45G128
                    D482 S/C RFUS20
                    Q521 23 ohm 3Y9L4
                    Q551 (dont trust) 3Y9L4
                    IC521 M18737 (Driver, suspect, cant test properly, will replace)
                    D422 s/c RFUS20
                    Q422 s/c RJP43F4A
                    Q421 s/c RJP43F4A
                    D402 s/c F50ALW
                    D401 s/c F50ALW
                    Q402 s/c D502LW
                    Q401 s/c D502LW
                    Q501 8.2 ohm 3Y9L4
                    IC501 M18737 suspect.
                    Q661 s/c RJP63F3A

                    IC771 78L05 O/P = 5K, I/P = 1.7K
                    Q818 reads odd but not s/c.
                    Q701 reads OK
                    Q702 reads OK
                    IC773 no apparent shorts

                    IC724 7805, reads ok, o/p 2.61K, I/P greater than 20M

                    All the above were checked on the board and nothing has been removed for further testing yet. I expect many of the above shorted parts will be found to be OK when the confirmed short components have been removed.

                    While I think of it, When testing out a board in the set with SC50 shorted, and buffers disconnected, is there any limit on time as to it being tested?
                    Could it say, be run for half hour before going further and fitting buffer etc....?
                    good question. No idea. I know if you ran the P board with no load for more than 30secs it'll 4 blink

                    Just getting settled and herding all my dead boards together. I need to clear out my stuff too much laying around.
                    Last edited by tw2005; 01-28-2016, 09:11 PM.

                    Comment


                      #11
                      Re: TNPA5105 rebuild

                      Q451, D481,Q421 Q422, Q401 Q402 and Q661 proved to be short and the shorts on the other heatsink mounted diodes etc have now gone since these items were removed...

                      The small dual-transistor pair such as Q521, Q551 Q501 Q531 and IGBT Driver chips, - IC501, IC521 I'll replace anyway, seeing they are reasonably cheap--The Dual Transistors are pennies, and the M81737FP I have on order

                      Q818, Q701 Q702 and IC773 I might as well replace as I cant confirm whether completely good or not, along with the two 5V reg chips....
                      TELEFIX

                      How PLASMA SCREENS WORK, X-SUS and Y-SUS what they do--
                      http://www.irf.com/technical-info/appnotes/an-1088.pdf
                      PLEASE DO NOT EMAIL ME PRIVATELY FOR REPAIR ADVICE. QUESTIONS BELONG ON THE FORUM!

                      Comment


                        #12
                        Re: TNPA5105 rebuild

                        Originally posted by Alastair E View Post
                        Q451, D481,Q421 Q422, Q401 Q402 and Q661 proved to be short and the shorts on the other heatsink mounted diodes etc have now gone since these items were removed...

                        The small dual-transistor pair such as Q521, Q551 Q501 Q531 and IGBT Driver chips, - IC501, IC521 I'll replace anyway, seeing they are reasonably cheap--The Dual Transistors are pennies, and the M81737FP I have on order

                        Q818, Q701 Q702 and IC773 I might as well replace as I cant confirm whether completely good or not, along with the two 5V reg chips....
                        should be a success, generally I find if those regs are bad they'll be shorted. I do find it interesting how this cct is virtually the same around q661 and Q818, Q701 Q702 and IC773 appear to not be shorted yet the 5081 everytime ic773 at least is shorted on Vcc.

                        Comment


                          #13
                          Re: TNPA5105 rebuild

                          I'm trying to get my head around the failure mode of these things--Why is it when they fail--So many small parts, IC773, Q701 Q702 et-al fail on the 5081 Cant work it out--Why do they pop-- Not as if they are directly connected to 661...

                          Stranger is how most times, they survive on the similar 5105.... It may be a 'Kelvin' issue, which would explain why 5105 doesnt always kill those parts...

                          I have all the parts now in stock--Except the Tosh VSSOP 'C541' buffer-chips, but those should be OK on the 5105's Those are on back-order from another RS Depot overseas...

                          Wish me luck--Tomorrow, I'll be Going In!
                          TELEFIX

                          How PLASMA SCREENS WORK, X-SUS and Y-SUS what they do--
                          http://www.irf.com/technical-info/appnotes/an-1088.pdf
                          PLEASE DO NOT EMAIL ME PRIVATELY FOR REPAIR ADVICE. QUESTIONS BELONG ON THE FORUM!

                          Comment


                            #14
                            Re: TNPA5105 rebuild

                            Originally posted by Alastair E View Post
                            I'm trying to get my head around the failure mode of these things--Why is it when they fail--So many small parts, IC773, Q701 Q702 et-al fail on the 5081 Cant work it out--Why do they pop-- Not as if they are directly connected to 661...

                            Stranger is how most times, they survive on the similar 5105.... It may be a 'Kelvin' issue, which would explain why 5105 doesnt always kill those parts...

                            I have all the parts now in stock--Except the Tosh VSSOP 'C541' buffer-chips, but those should be OK on the 5105's Those are on back-order from another RS Depot overseas...

                            Wish me luck--Tomorrow, I'll be Going In!
                            I occasionally use RS, how did you go about ordering them? On my site they're not even shown and the only RS site I found them was Japan.

                            Comment


                              #15
                              Re: TNPA5105 rebuild

                              Toshiba TC74VHC541FK(EL,K), Octal Bus Buffer, 10.5 ns@ 3.3 V 8mA, 2 → 5.5 V, 20-Pin VSSOP

                              RS Order number, 581-776

                              I use the RSWWW website--UK Based--Maybe you can try that one....

                              I did a search on their site, it came up so I just added them to the other items I had on order...

                              --Some other parts I ordered from Farnell contained a 5 legged Comparator single, micropower 5SOT23, TS391ilt but cant for life of me remember What its for--summit on 5081 I'm pretty sure Maybe rings a bell with you?....
                              Last edited by Alastair E; 02-03-2016, 05:14 PM.
                              TELEFIX

                              How PLASMA SCREENS WORK, X-SUS and Y-SUS what they do--
                              http://www.irf.com/technical-info/appnotes/an-1088.pdf
                              PLEASE DO NOT EMAIL ME PRIVATELY FOR REPAIR ADVICE. QUESTIONS BELONG ON THE FORUM!

                              Comment


                                #16
                                Re: TNPA5105 rebuild

                                Well--Ive replaced all the small parts and made a start on refitting replacement IGBT's etc.
                                --Ran out of time today, as I had left it late to start on this project.
                                --Two soldering-irons certainly makes life easier doing the tiny stuff. I have a needle-point and a std chisel tip. Worked a treat.

                                One test I did which concerns me, is the Output DC resistance of IC771 the 5V reg.
                                --On the 5081 thread, a resistance of 5.6-6.1K is a correct figure--but that's for the 5081....

                                My board--with the new parts and no apparent shorts is 5.1K Ive checked the opto thats supplied by that line--removed it, but the resistance does not alter.
                                --Checked D702 and most of the small stuff round IC773, all looks good.

                                It could be that the 5105 just has a slightly lower resistance in this line--TW, What are your thoughts...?
                                --Those C541 buffers maybe (Haven't received the ones I ordered yet, or I would have pulled them to see...)

                                Dont want to blow the board up again, so any advice would be great...
                                Last edited by Alastair E; 02-04-2016, 01:41 PM.
                                TELEFIX

                                How PLASMA SCREENS WORK, X-SUS and Y-SUS what they do--
                                http://www.irf.com/technical-info/appnotes/an-1088.pdf
                                PLEASE DO NOT EMAIL ME PRIVATELY FOR REPAIR ADVICE. QUESTIONS BELONG ON THE FORUM!

                                Comment


                                  #17
                                  Re: TNPA5105 rebuild

                                  Originally posted by Alastair E View Post
                                  Well--Ive replaced all the small parts and made a start on refitting replacement IGBT's etc.
                                  --Ran out of time today, as I had left it late to start on this project.
                                  --Two soldering-irons certainly makes life easier doing the tiny stuff. I have a needle-point and a std chisel tip. Worked a treat.

                                  One test I did which concerns me, is the Output DC resistance of IC771 the 5V reg.
                                  --On the 5081 thread, a resistance of 5.6-6.1K is a correct figure--but that's for the 5081....

                                  My board--with the new parts and no apparent shorts is 5.1K Ive checked the opto thats supplied by that line--removed it, but the resistance does not alter.
                                  --Checked D702 and most of the small stuff round IC773, all looks good.

                                  It could be that the 5105 just has a slightly lower resistance in this line--TW, What are your thoughts...?
                                  --Those C541 buffers maybe (Haven't received the ones I ordered yet, or I would have pulled them to see...)

                                  Dont want to blow the board up again, so any advice would be great...
                                  On my broken board I have 6-6.2k depending on the probe direction. The 5v reg and q701,701,818, ic773 are untouched(originals)

                                  Comment


                                    #18
                                    Re: TNPA5105 rebuild

                                    Looking at the scheme, There's only IC773, the opto, D702 C708 and Q649 directly connected to that Vad+5V

                                    I'll pull the (new) reg and that Q649 tomorrow--See whats happening--If they are good, must mean D702 has a slight leak, Only other thing is a MLCC near the reg itself...

                                    Already replaced Q818, IC773, Q701, Q702....
                                    Last edited by Alastair E; 02-04-2016, 03:22 PM.
                                    TELEFIX

                                    How PLASMA SCREENS WORK, X-SUS and Y-SUS what they do--
                                    http://www.irf.com/technical-info/appnotes/an-1088.pdf
                                    PLEASE DO NOT EMAIL ME PRIVATELY FOR REPAIR ADVICE. QUESTIONS BELONG ON THE FORUM!

                                    Comment


                                      #19
                                      Re: TNPA5105 rebuild

                                      Originally posted by Alastair E View Post
                                      Looking at the scheme, There's only IC773, the opto, D702 C708 and Q649 directly connected to that Vad+5V

                                      I'll pull the (new) reg and that Q649 tomorrow--See whats happening--If they are good, must mean D702 has a slight leak, Only other thing is a MLCC near the reg itself...

                                      Already replaced Q818, IC773, Q701, Q702....
                                      If you replaced that 78L05 with a different brand chip then that could be a reason. I've seen that and true to say that resistance measurements are only good as a rough guide for a clue if something may be wrong.

                                      Comment


                                        #20
                                        Re: TNPA5105 rebuild

                                        Yup--Thats what it was, Different make 78L05 reg...

                                        I checked a new unused 78L05 chip, O/P to Gnd, = 5.1K I'm guessing this must be the internal pot divider for the feedback....

                                        Now--Finished up re-populating the heatsinks, gave the board a good going-over for any other issues and all set to go.....

                                        Or so I thought.

                                        Due to a massive brain-fart and Monumental Cock-Up on the SUS board rememberance Front, Ive found that the set I intended to use this board in has a Completely Different SC-- In fact, Its Not Even an SC, but an SN! A TNPA5066 to be exact.

                                        Dunno what had convinced me that this set used 5105....

                                        So--Ive got a rebuilt Untested 5105 and a dead 5066..... Doh!

                                        I'm thinking I could test this 5105 in the 42G20 that I buggered up the 5081 in, as I did an opposite swap using a 5081 in place of a 5105. A job for Sat Afternoon when the place is quiet.......
                                        TELEFIX

                                        How PLASMA SCREENS WORK, X-SUS and Y-SUS what they do--
                                        http://www.irf.com/technical-info/appnotes/an-1088.pdf
                                        PLEASE DO NOT EMAIL ME PRIVATELY FOR REPAIR ADVICE. QUESTIONS BELONG ON THE FORUM!

                                        Comment

                                        Working...
                                        X