1. Time for some upgrades in server hardware and software to enhance security and take AK to the next level. Please contribute what you can to sales@audiokarma.org at PayPal.com - Thanks from the AK Team
    Dismiss Notice

Tascam BR-20 VU lamp replacement

Discussion in 'Tape' started by phantomrebel, Nov 4, 2017.

  1. phantomrebel

    phantomrebel Serial Tapist Subscriber

    Just a quick writeup for BR-20T noobs like myself as I think blown VU lamps in these decks is a common problem (3 out of the 5 decks I looked at had blown lamps) and they are easy to replace.
    All you need to do is remove the bottom 2 screws on the lower faceplate then tilt this faceplate up so it locks in place...nice feature! (I removed the knobs and other screws for service, but you don't have to for this bulb replacement project).
    tas4.JPG
    Locate the board under the VU meters that is held in by two screws. Unplug the side connectors (two on left, one on right) then remove the two screws. The board will pull down (note there is a black plastic friction post in the rear center of the board that also needs to be released). The board will now dangle from three additional connectors along the top which now can be unplugged to remove the board and bring to the work bench.
    tas7.JPG

    The plastic lens covers are taped to the backplates. To separate, you just need to remove the tape strip running side to side along the bottom front and then fold the lens back (the piece of tape at the top center acting as a hinge). This exposes the axial lamps that are soldered in. The replacements commonly available are clear while the OG's are frosted. I used 8V L24's from StudioSound.
    tas10.JPG
    Simply put your hot iron briefly on the soldering tabs to release the old lamp, then place the new axial across the tabs, hit it again briefly with the iron and then snip off the excess wire. There was enough original solder on the tabs that I didn't need to add any.
    tas12.JPG
    When done, replace the lenses, put new clear tape across bottom, reattach the connectors and push the board back in (be careful to align the green timecode lamp, friction pin, and lenses before finally setting it in). Put the screws back in, close the faceplate, reinstall knobs and screws and your done. Maybe a 15 min procedure and less than $6 in parts so you have no excuse to live with dark meters. I thought about LED replacements (with resistors), but I like the old school glow that matches my other equipment.
    tas13.JPG
     
    Last edited: Nov 8, 2017
    nascar03 and Skylab like this.

     

    Please register to disable this ad.

  2. Skylab

    Skylab Altimeter reading zero Subscriber

    Messages:
    5,404
    Location:
    Chicagoland
    Excellent write up, thanks!
     
  3. nascar03

    nascar03 Active Member

    Messages:
    184
    Location:
    Langley, BC
    Hey pr...
    Thank you for this great write-up.. and the pictures are perfect.
    Two of my decks need this done.
    I’ll have to get out a lamp order soon.

    Thanx again.
    Graham
     
  4. Beemerdoc

    Beemerdoc Grumpy Old Fart Subscriber

    Messages:
    606
    Location:
    Sarasota, Florida
    Nice job!

    I have a silly question:

    Why do the bulbs come in a 3 pack when there are only 2 meters on the machine?

    :wtf:
     
  5. phantomrebel

    phantomrebel Serial Tapist Subscriber

    Not sure, but there are a few Tascam decks (e.g. 133B cassette) that have 3 meters. Then again, there are reel decks with 4 and 8 so a 3-pack is weird. Cheap enough though so OK to have a spare. To keep things odd, Dynamictechgroup sells them in packs of 5! I think they sell similar axial lamps individually at some of the big electronics parts distributors, I just don't know the part numbers as I didn't go through all their catalogs. Stock was 8V, 55 mA (I think someone said they are actually running at 6.8V?), but perhaps up to 150 mA will work. In my search, I did not find any that were frosted like the originals. I wish Teac parts still sold them as they have a limited life. At some point, I may solder on some LEDs and resistors since it is so easy.


    EDIT: I'm an idiot...I checked and I actually ordered 3. SSE sells them in singles at $1.95 each. I forgot I ordered an extra in case I F-d up. A senior moment!
     
    Last edited: Nov 7, 2017
    nascar03 likes this.
  6. dhnash

    dhnash Well-Known Member

    Messages:
    500
    Location:
    Wildwood, MO

     

    Please register to disable this ad.

  7. phantomrebel

    phantomrebel Serial Tapist Subscriber

    Last edited: Nov 7, 2017
  8. nascar03

    nascar03 Active Member

    Messages:
    184
    Location:
    Langley, BC
    I’ll have to do some looking for a lamp source in Canada.
    I checked on the StudioSound site and 6 bulbs are $11.95 but shipping is another $14.00.
    If anyone knows of a Canadian source please let me know.

    Graham
     
  9. dhnash

    dhnash Well-Known Member

    Messages:
    500
    Location:
    Wildwood, MO
    nascar03 likes this.
  10. phantomrebel

    phantomrebel Serial Tapist Subscriber

    Yes, I know, I bought the Rustoleum stuff you suggested as well. I always love to experiment!


    Graham:
    I think this is the one distributors sell: http://www.jkllamps.com/incandescent/axialleadlamps/DA513 (I should have bought direct at $1/ea., but I didn't think I needed 20, now though, with these color experiments it's tempting).
    Mouser and Newark sell JKL stuff in Canada
     
    Last edited: Nov 7, 2017
    nascar03 likes this.
  11. nascar03

    nascar03 Active Member

    Messages:
    184
    Location:
    Langley, BC
    AEBBC727-00BA-4930-925A-79883121004F.jpeg

    I wrote a note to the local supplier this afternoon, SMI Electronics here in Langley, BC.
    Sure enough they had some L25’s in-stock. 12V, 35ma. $1.35/each. !,!
    I’m going to try these very soon. I didn’t ask about coloured lights.
    I have 3 BR-20 decks to fix.
    thanx a bunch..
    Graham
     
    phantomrebel likes this.

     

    Please register to disable this ad.

  12. phantomrebel

    phantomrebel Serial Tapist Subscriber

    12V, 35 mA is much different than the 8V, 55 mA folks have used. How do you think they'll perform?
     
    Last edited: Nov 7, 2017
  13. nascar03

    nascar03 Active Member

    Messages:
    184
    Location:
    Langley, BC
    I’m thinking slightly dimmer and draws less current...
    I’m not an electronics engineer but I did stay in a Holiday Inn once.

    Graham
     
    phantomrebel likes this.
  14. nascar03

    nascar03 Active Member

    Messages:
    184
    Location:
    Langley, BC
    Hey PR...
    Thanx for the thread. It pushed me to fix my deck...
    I picked-up the bulbs locally as per above. 12V 35ma.
    Mine is not a BR-20T ..(timecode deck) so maybe it was slightly different.
    I did not have to pull the front knobs at all.
    8D71F71B-0B35-42FD-95CF-B702A0F45A3C.jpeg
    First loosened the two screws retaining the meter board..see yellow arrows.
    Then carefully removed the three connectors, as you mentioned..circled in red.
    This was a delicate job... I was worried I would break something.!
    Rolled-up paper towel was placed so the screws could not fall into the machine.
    Then removed the two screws and carefully pulled the board out/down a bit.
    This allowed access to the three remaining connectors in the rear of the board, circled in blue.
    The whole assembly could now be removed.
    506A922C-7A7D-4120-9966-3D547E011A2F.jpeg
    On my machine the tape holding the meter clear covers was on the sides. Once I cut the tape the meters opened-up as you stated.
    693F04C9-40D1-4C8A-8F90-4802E146BB9D.jpeg

    96CAE3E1-FBAB-44CA-A419-9FA7223756B3.jpeg

    I proceeded to unsolder the old frosted lamps and installed the new units.
    And taped the lenses back up.
    7C5B1386-4514-4B9C-8034-8C5AA3B08C51.jpeg

    Put the board back in place, redid the six connectors, installed/tightened the two board retaining screws, write a note inside the machine with the date, closed it up and plugged it in,
    D98C99CC-D4B5-49A6-A214-DB72DF23FA40.jpeg

    Voila!,,,,,,
    50944E44-C640-4EEB-8855-46C678A3D938.jpeg

    Thank you a bunch for getting me going on this.. I have two more machines to do.
    It took me about 30 mins to get this done. The toughest part was carefully undoing those circuit board connectors..
    With these lamps being rated for 12V I thought they would be dimmer in this application...but they look OK.
    I would like to see what coloured ones look like.
    I hope others find this helpful.

    Graham
     

    Attached Files:

    Last edited: Nov 8, 2017
    phantomrebel likes this.
  15. phantomrebel

    phantomrebel Serial Tapist Subscriber

    I just looked again and you are correct Graham...no need to pull the knobs! I was doing other maintenance beforehand and took them off. I edited my original post to reflect this. Anyways, good job, I'm glad those lamps worked out...Looks great!

    Also, the existing tape on mine was on the sides as well, but wrapped all the way along the bottom from one side to the other:
    IMG_6905.JPG
     
    Last edited: Nov 8, 2017
    nascar03 likes this.
  16. phantomrebel

    phantomrebel Serial Tapist Subscriber

    Just finished playing around with different frosted spray paints. It was interesting to compare the Rustoleum clear product to the blue shaded Krylon aqua product.
    IMG_6952.JPG
    Before treating VU meter lamps, I first tested on household 50W MR16 lamps because they have large clear lenses and, as those of you that ever changed one knows, they get hot as hell under use. I did 2 coats on each and let dry overnight. A fingernail scratch test along one side showed that both finishes could be removed, but the aqua paint felt soft (more gel like) while the clear was hard (flaked off).
    IMG_6946.JPG
    I put them in some recessed cans for an hour and took some measurements. A similar untreated lamp measured 320 LUX and 220 deg F. The clear coated was similar at 300 L and 225 deg. The aqua was 180 L and 240 deg, so less light output and more trapped heat with the color. When removed and examined, it was clear the aqua finish suffered a bit, with discoloration near the center of the lamp whereas the clear sample was unaffected. I did another scratch test and the aqua was again softer.
    IMG_6949.JPG IMG_6950.JPG

    So I conclude that the colored paint is likely not going to hold up as a long-term lamp coating. The clear product appears more suitable, so I used it to coat my 8V axial lamps, where it appeared to diffuse the display projection a bit. Thanks to dhnash for the suggestion!
     
    Last edited: Nov 12, 2017

     

    Please register to disable this ad.

  17. R-2-R

    R-2-R AK Subscriber Subscriber

    Messages:
    2,078
    Yes, most definitely agree, "excellent write up" ! :thumbsup::trebon:
     
  18. dhnash

    dhnash Well-Known Member

    Messages:
    500
    Location:
    Wildwood, MO
    Glad to hear that the clear frosted paint worked out well for you. Using it is probably much easier and safer than using other glass etching methods to frost the glass lamp envelopes.
     
    nascar03 likes this.
  19. nascar03

    nascar03 Active Member

    Messages:
    184
    Location:
    Langley, BC
    Dhnash and phantomrebel... thanx to you both for this frosting attempt..
    Great info. Great idea.
    Graham
     
  20. nascar03

    nascar03 Active Member

    Messages:
    184
    Location:
    Langley, BC
    OK.. worst fear realized.... was changing the bulbs in my 3rd deck..
    And a broke off the wire to the two-pin connector..!!!
    AAUURRGGHH!
    0AC7454D-2D5E-4B61-81B8-5BB1FF2C2909.jpeg 74A8AA22-E4D3-43F6-857B-3E11E55E8263.jpeg

    I stripped off 1/8” of the white insulation hoping to maybe re-insert the wire into the connector again.
    This was not going to work. Darn.
    I’m thinking soldering is going to melt the connector.
    I went to a local electronic supply store yesterday to see if this is a common connector. Nope.
    A friend said these connectors may be used in computers and such, so I stopped in at a couple of repair shops but no luck there either.
    Maybe there is someone out there dismantling a BR20....?
    It would be nice if I could get this connector with a 2-3” pigtail of wire. Then I could solder wires together instead of at the connector.
    I studied the schematic to see what is happening..this is apparently a 15v feed to the board.
    The meters and ‘peak’ lights still work in both input & output modes..?
    What seems to be NOT working now is the variable speed lights. Vari/Fix/Ext...but that is on another circuit board.
    A little more studying will be needed to figure this out.

    If anyone knows of, or has a BR20 being dismantled please let me know.
    Thanx
    Graham
     

Share This Page