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Planet 2000 cdp fix: redux!

Discussion in 'd.i.y.' started by The Captain, Feb 7, 2023.

  1. The Captain

    The Captain ~~~~~~~~~~

    Hi chaps,

    following my 'Wot rail grease?' thread, I asked about getting at the laser/ transport.. but I got in a heap of confusion. So I need to start afresh.

    My symptoms. Cdp has bad Skipping. It reads TOC fine tho. I find the more scratched the cd the worse the skips. Lens cleaning did zilch. So: I greased rails, & this possibly helped (I think, but it still skips tho).

    Ok 1st up. How to uncouple the transport from the pcb below. It is connected by 1 ribbon cable.
    Pic 1 shows something blue.. this is just holding the tray up for the photo.

    How to (safely) decouple the ribbon cable, pointed to in pic 2.. is where I am stuck at.

    Pic2. Allen key is pointing to the ribbon cable: I think I can't just pull it out: is this correct?

    Pic 3. Pointer to 2 tiny tracks, where a solder spot is. Now this is -possibly- somehow relevant to the removal of the ribbon cable (but I have no clue & very confused.. if someone could explain?).

    Thanks, Capt.

    Last edited: Feb 7, 2023
  2. The Captain

    The Captain ~~~~~~~~~~

  3. The Captain

    The Captain ~~~~~~~~~~

  4. a.palfreyman

    a.palfreyman pfm Member

    This is what I'd do under these circumstances.
    Buy an ESD wrist strap / lead-out wire.
    Rinse my hands under to cold tap and dry (to reduce skin resistance)
    Fit ESD strap to wrist.
    Clip the croc clip of the ESD strap to the earth plane of the mech.
    Remove the ribbon and then the mech from the machine.
    Whilst working on it, keep the wrist strap connected to earth plane of mech so both you and mech are at same potential.
  5. Craig B

    Craig B Re:trophile

    Hello Capt.

    The ribbon cable pulls straight out of the socket, however, it must be kept square else risk damage to the contact pins.

    If the solder spot in question is on the optical block PCB then this is an anti-static safety measure. Once a new optical block is installed, the solder bridge is removed from here to enable the circuit.
  6. Dowser

    Dowser Learning to bodge again..

    Shiiiiite - I’ve replaced more than 20 of these, never used anti-static straps, just careful not to touch electrical points once ribbon is disconnected, and remember to remove blob of solder before powering back up - just replace the damned thing already @The Captain :D
    cupples likes this.
  7. The Captain

    The Captain ~~~~~~~~~~

    Hi 'freyman, thanks for this detailed advice. This looks to be the optimal way/ as you do it. And very useful info, as it describes to me -why- such a procedure, however done, is important.

    I needed just this clarity to progress, grateful for this.

  8. The Captain

    The Captain ~~~~~~~~~~

    Hi there Craig. Like a knight clopping along to help. Really reassuring.. thanks for reply!

    Great. So now I'm clearer (but not 100% certain) about what's needed -prior- to pulling cable out. As much as the uncoupling is gonna be tricky, esp to insert back in (gulp).. it was the fug of this ruddy solder spot to clear up 1st.

    So. I need to first ID where this solder spot is/ get a better pic up ( pics proving a nightmare to insert into posts tho.. tried all afternoon to do these ^). I think I might know where it is. Pic 3 tried to shown it.. but not a great pic.

    Then to confirm: this awol-of-solder position (two small contacts, with 2mm gap between) IS indeed the correct place in question.. then to determine if the following is correct:

    I need to ADD a solder joining the two/ to bridge this gap.. prior to then being in "safe to proceed", to uncouple the ribbon. I need to confirm, that this is correct (( as has been the very nub of my confusion )).

    Thanks, Capt
  9. The Captain

    The Captain ~~~~~~~~~~

    Hi dowser. Im glad to hear it could possibly be feasable to replace something.

    It's just locating this mysterious solder blob. This is simple to you, but not to me having never been inside before.
    I can only find a position that is --possibly-- where you could be referring to, but, it has no solder blob: so I'm left utterly bewildered.

    What has opened up as a possibility though (after luterally wracking my brain for days in this) is this position I find... might... be needing me to ADD a solder to, in order for this mysterious " blob" then to materialise.

    I think therefore, this mystery "blob" isn't to be found, presently, in the cdp as I find it. So Ive been days looking for something... that was never even there. Even writing this my head hurts, & a fug of confusion starts.

    I will add a better photo, of this position in my cdp as I find it now, which I --think-- possibly is the crux spot.

  10. The Captain

    The Captain ~~~~~~~~~~

    Chaps. Here (finally!!) is the photo, of the place I need to ask about.

    I have put an arrow to two small square 'track ends'. I want to establish if these two 'track ends', soldered together, then becomes this mysterious solder 'blob'. If you could kindly zoom in to my arrow position.

    Question 1: Do I solder these two together?
    Question 2: If so, does this then means I can safely undo ribbon cable?

  11. The Captain

    The Captain ~~~~~~~~~~

    Wider shot..

  12. Dowser

    Dowser Learning to bodge again..

    Oh lordy... Go look in this thread -

    Then search for;
    "Home straight - re-assembly. Do *not* forget to remove the solder blob protecting the new laser from static - here it is removed"

    3 quarters of way down page. This is blob removed - required for normal operation. Your new mech or laser unit will have a blob between these points that must be removed before the unit will work.

    Good luck, Richard
  13. Craig B

    Craig B Re:trophile

    I don't know about being like a knight clopping along, Capt, more of a 'Monty Python's Life of Brian' like informed peasant making flippant comments from the side of the road.

    Regardless, according to the service docs from back when Planet 2000 was current, there is no specific instruction to remake the solder bridge. The assumption here being that one is changing out a failing optical block, so why bother. Removal of the ribbon cable isn't necessarily going to make the optical block be more or less sensitive to static discharge, it is down to the technician working on same to ensure that static isn't going to be a problem. In aid of this, simply avoiding touching any terminals and or pins on any PCB is sound advice.

    On the other hand, should you be more interested in trying a thorough cleaning of the rail upon which the current optical block rides, as well as a good cleaning of the sleeve that encircles same, then someone upthread mentioned simply bridging the two solder pads with a crocodile clip (perhaps with a small metal spacer across as shim). A good tip that.

    As to specific instructions for changing out the mech or optical block within, the four screws that attach the mech to the tray are to be removed, whereupon the mech is slid back away from the tray at the same angle as is the slot in the tray through which the laser head travels (i.e. at an angle to the front to back of the tray itself), this until the mech can be easily fully separated from the tray.

    I'll PM you an instruction sheet as to how the optical block is subsequently removed/replaced on the Sony, post removal of the mech from the tray.

  14. The Captain

    The Captain ~~~~~~~~~~

    @Craig B I'm adamant you are indeed my cloppity horse knight.

    I can make full sense of your post- & yes the thinking at this early stage, was to inspect the rails/ look for cracks in a gear wheel/ look foranything that might suggest a reason for my skipping. And then to get some silicone grease into the areas I just can't get at, with it being tethered, by its umbillical cord.

    What I first wanted to establish though, was whether or not, I have found where this (still mysterious) 'blob' of solder might be located: you see I'm in a catch22. Because if where I point to ( in my most recent photo, a yellow arrow) is indeed this location... it is devoid of this blob ( as I find it now). So providing me with a photo, of this solder blob having been made, is of no use, because I cannot match it to what I find. What I find, is no solder blob. Catch 22.

    If someone could just look at my photo. It has two 'vacant' tiny square track 'ends', marked by a yellow arrow.
    Now, I cannot see any other location, where any possible 'blob/ bridge' could, possibly be implemented/ added.

    So I can make a fair guess that this place, is, where this blob of solder, this bridge of solder, is to be added,min the future. But a 'fair guess' by me, isn't good enough. I need someone to verify it.

    It's either

    A) yes that is indeed where you add the solder.


    B) no that is wrong, it's somewhere else you need to find.


    C) I cannot be sure from your photo.

    Thanks, Capt
  15. Craig B

    Craig B Re:trophile

    And the answer is...

    A) (modified) Yes, that is indeed where the solder was added during manufacture in order to short the input until such time as the block was installed, the two solder pads being in-line with those of the ribbon cable socket.

    Specifically, it is a Sony KSS-213B. In this shot of a new replacement optical block you can clearly see the solder blob at top right of the small vertical PCB.

    As bonus you can also see the toothed gear rail and the two sintered bronze sleeves that slide along the metal guide rail (both lower left).


    P.S. The ribbon cable here is not the same as the one you indicated within your first photo above. This ribbon is between the main mech PCB and that of the optical block. You can safely disconnect the larger ribbon from the mech prior to removing the mech and CD tray assembly from the player. The smaller ribbon is disconnected after the guide rail (i.e. metal rod) is removed and during the lifting out of the optical block (as per the instructions sent).
    Last edited: Feb 9, 2023
  16. The Captain

    The Captain ~~~~~~~~~~

    @Craig B fantastic I'm a heap closer to understanding after that (& pics great for the future).. but not fully understanding even so. Almost though.

    Just to reitterate, I'm only at this stage concerned with this blob. So confusing it has been. I'm nowhere near progressing onto removing optical blocks (but think this would take far less time than my week + so far on this blob).

    Ok great. I've confirmed where this blob materialises. And now I know why I don't see it on my mech presently.

    But Im still not understanding what this solder blob has relevance to. The large-main " umbilical cord " ribbon connector undoing?... or... to the smaller ribbon connector disconnection (this ribbon moves with the optical block)?

    Why do you do it? And when do you do it?

    You see if it has sole relevance to the decoupling of the smaller ribbon cable, I can go ahead now & gently pull the main pcb " unmbillical cord ". Then I'm into the next step, that being: creating this solder in preparation for untethering the optical block. I can also get access to my blob location fine if this is the case.

    But if it has relevance prior to this, to the decoupling of the main " umbillical cord " ribbon connector.. I need to create this solder bridge NEXT. As to how, is frankly beyond me as getting access to this location is hampered of course, by the "umbillical cord " (so I'd be in yet another Catch22 afaict. Groundhog day now).

    Thanks, Capt

    Thanks, Capt
  17. a.palfreyman

    a.palfreyman pfm Member

    What @Craig B is saying is that the ribbon in your image post #2 can safely be removed. Once you have the mechanism out and on the bench, you only need to consider the addition of the solder blob before you disconnect the laser circuit from the mech via it's own ribbon cable. If you are simply replacing a sha99ed laser, don't worry about adding a solder blob, just remove the ribbon. When you fit the new laser, insert the ribbon cable and then you are safe to desolder the blob.
    I'm not familiar with this particular mech but the shoulders on the fitting in @Craig B's last photo may need lifting to release the laser ribbon cable. Edit: cable is straight pull out / insertion ref below.
    This is certainly the case with ribbon connectors on the vam1205 and cdm2 mechs I've worked on.
  18. Craig B

    Craig B Re:trophile

    Is that Sonny Bono on the flip-clock radio again?

    Let's backup a bit here first.
    1. The solder blob is applied during manufacture such that the optical block is protected from damage due to static discharge during subsequent handling.
    2. The solder blob prevents the optical block from functioning by shorting input to the microprocessor chip (which is how the chip is protected from static discharge)
    3. The solder blob is removed during installation of the optical block into a transport mech (else nothing works).
    When changing out an optical block:
    1. It isn't strictly necessary to apply a new solder blob only to have to remove it again a minute later (which is about how long it takes to change out a block once the mech is separated from the CD tray, that is, sans any cleaning/re-lubrication of parts). One does need to take precautions such that there be no static discharge between person and/or tools and circuitry. An anti-static work mat with attached wrist strap is best, however, most techs will simply pull the block and pop in a new one after having desoldered the shorting blob (although this desoldering can be performed after attaching the smaller ribbon cable, if one carefully flips the optical block over with ribbon attached before aligning the block and reinserting the guide rail).
    2. There are other methods of temporarily shorting input to an optical block and/or entire mech. These include pulling the ribbon cable from the opposite end connector and sliding a bare metal paper clip across the bare ribbon contacts. Another method would be attaching a crocodile clip across the two solder pads that the blob originally bridged. The irony here is that doing either could kill the chip as your are touching the circuitry. IOW, don't touch the circuitry.
    In conclusion:
    1. Your mech doesn't have a solder blob here else the deck wouldn't work, period.
    2. You don't really need to replace the solder blob for a 5min clean/lub and/or replacement job.
    3. Just be careful wrt static discharge whilst working. Some tips were mentioned previously, such as discharging any static from your person by touching a grounded object before commencing work, washing your hands to restore moisture (not wet hands, just not too dry), even spritz some water onto the carpet should there be any in your work area upon which you walk round (especially so, with the heating on this time of year).
    4. Don't touch the circuitry.
  19. Craig B

    Craig B Re:trophile

    The ribbon connectors are straight push in/pull out on these Sony mechs, Andy.

    Emphasis on 'straight'.
    a.palfreyman likes this.
  20. a.palfreyman

    a.palfreyman pfm Member

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