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Part Identification Help - Braun 6520 Shaver board

Discussion in 'Troubleshooting and Repair' started by Tesla, May 10, 2010.

  1. Tesla

    Tesla

    165
    2
    May 10, 2010
    Inside on the main circuit board, right past were one leg of the AC power cord connects, there is a small orange box looking part. It's square 1/4"x1/4"x1/8" and has the markings "W T280mA" on it ... what could it be? I fuse maybe?

    www.electricshaverstore.com/get_item_5503625_braun-circuit-board-w-batteries.htm

    I think the W stands for Westinghouse.

    My shaver was working yesterday, but now it won't turn on at all. For the past few months it only worked at full speed on AC corded power (so I'm pretty sure the batteries were going out).

    There is no continuity through the part so I can understand the shaver being totally dead now because I don't see how the AC power can get to any other part on the board.

    I unsoldered the AA sized batteries to check/replace them. They aren't marked so I'm currently trying to get them cross refed. at the shaverstore. I have one of the 2 cells on the R/C charger now... as NiMH 1600mA (single cell) 1.2v - Charge rate 800 mA and it seems to be charging.

    So anyway, what could the part be and where can I get one? As you can see, there is really no room for a conventional fuse (if that's what it is).

    Thanks.
     
    Last edited: May 10, 2010
  2. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,178
    2,690
    Jan 21, 2010
    Sounds like a fuse. T possibly means that it's a slow blow fuse (or maybe it doesn't).

    If you can remove the fuse (desolder it) then you may be able to fins a suitable replacement.

    It may be best to replace the cells with known good new ones. But try charging them first. It is possible that one cell is a little weaker than the other leading to it being over charged, over-discharged and damaged.

    I've had a brief look for a fuse of that size without success. Is it through-hole, or surface mount? Can you provide a photo?
     
  3. 55pilot

    55pilot

    434
    3
    Feb 23, 2010
    Assuming that this is a fuse and you can find a replacement, you are stuck paying for the fuse.

    Then you are going to pay for replacing the batteries under the assumption that they are bad.

    Then you may find out that whatever killed the fuse is not the batteries and the new fuse is dead too. So you are looking to buy another fuse and who knows what else to fix the underlying problem or buying the whole board.

    Or you may find out that it is not a fuse and you just made your problems worse. Now you are looking at buying the whole board.

    You may also find out that the batteries were not bad and it was the charger that was dying. Once again you are looking at buying the whole board.

    The smart thing may be to cut your risk and just buy the board. The additional cost over the cost of the batteries and the fuse may not be that much.

    ---55p
     
  4. Tesla

    Tesla

    165
    2
    May 10, 2010
    I edited my first post of the URL to the picture. I can try to get a better one if you think it will help.

    Come to think of it, I have seen little black transistor looking devices (but only 2 legged) in some old Hitachi VCR power-supplies before. They called them "Circuit Protectors". As I recall, they where on the 5 volt line right before it left the PS.

    Yes, this part is hole through. Most parts are on this single-sided PCB, but there are a few SMT on the bottom as well (one of which is a 16 pin IC chip). I'm pretty sure the IC chip's job is to monitor the battery voltage and flash the 2 leds appropriately. However, it might also control the charging.

    Hopefully, the guys over at ElecticShaverStore can tell me the chemistry, voltage, and amperage of the cells. Then I can see about getting replacements. Their's will be pricy, but guaranteed to fit (and probably fairly fresh). Know a better source?

    The first battery charged ok at the settings I used on the Triton (first post). It got up to 1700mAh @ 1.45v ... it didn't peak out but was getting a little warm so I took it off. I have the second one on now. The Triton charger says it's good enough to charge and has loaded about 500mAh into it so far. It's looking like these batteries are ok, but it won't be the first time that the Triton charger can charge/cycle/recondidtion a battery when the original device couldn't.

    By the way ... this website is totally cool. Thanks so much for setting it up.
     
    Last edited: May 10, 2010
  5. 55pilot

    55pilot

    434
    3
    Feb 23, 2010
    I am sure those guys are smart enough to know what you are up to. You may find it hard to pin them down on the battery specification. They make no money if you buy from elsewhere.

    ---55p
     
  6. Tesla

    Tesla

    165
    2
    May 10, 2010
    Parts for repair

    I think this is the correct replacement fuse part. Am I looking at the exact correct specced one ( 280 ~ 315) ?
    http://search.digikey.com/scripts/DkSearch/dksus.dll?vendor=0&keywords=507-1171-ND

    The batteries are here ... so they ARE solder tabbed 1.2v AA sized NiMH 1650mAh:
    http://www.electricshaverstore.com/get_item_r17.htm

    ... sure wish I could find the batteries cheaper (shipped) ... $11 for a $3 battery (2x $11 + $5 s/h = $27 total) ... you are definitely paying a premium.

    This shaver was $100 new about 5 years ago. A new comparable model (Series 5) is $150.
     
    beckjm likes this.
  7. 55pilot

    55pilot

    434
    3
    Feb 23, 2010
    $27 for the battery. About $6 for the fuse (Digikey has a $5 handling charge for orders under $25). You are already up to $33 plus whatever it will cost if there are others problems on the board that caused the fuse to blow. Just spend the additional $10 and buy the board with the batteries you have linked in your first post. Saving that $10 may end up costing a lot more than $10.

    ---55p
     
  8. Tesla

    Tesla

    165
    2
    May 10, 2010
    The old batteries checkout ok on the R/C Triton charger.

    I went ahead and installed a new set of conventional NiMh batteries and a 300mA slo-blow glass fuse (in holder) outboard (all parts I had laying around).

    The fuse still blows so there is something else wrong with the board (or possibly the motor I suppose).
     
  9. 55pilot

    55pilot

    434
    3
    Feb 23, 2010
    If the fuse bows before you turn on the motor, it is unlikely to be the motor.

    ---55p
     
  10. Tesla

    Tesla

    165
    2
    May 10, 2010
    Oh, right.

    Well, I found another problem.

    I think I mentioned that the underside of the board has SMT parts on it (including a 18 pin IC). Well along with all the SMT diodes etc., there is a SMT transisor with a hole blown in it. All the magic smoke escaped :(
     
  11. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,178
    2,690
    Jan 21, 2010
    I don't suppose you can read any markings on this device?

    You'd need to know what to replace it with, and if it's died in such a dramatic way, then chances are that it's another casualty of the initial fault, rather than the root cause.

    I think that fixing this is more likely to be of academic interest than economically justified. However that does not mean it's not worth doing. If you are sufficiently interested, and willing to spend close to the price of a new one with no guarantee of success -- go ahead. I've fixed stuff like this before (i.e. not economically justifiable) but I've also failed.

    The easiest route may be to get the new one (or another one) and then use it to help ID the parts.

    Trying to trace out a circuit diagram is probably a good thing too.
     
  12. Tesla

    Tesla

    165
    2
    May 10, 2010
    The shaver lasted 5 years, so I'll just put the board's $45 toward a new razor that should last another 5 years.

    It would be purely academic. But since this appears to be the worlds smallest SMPS, so I'm not sure it's a good canidate.

    The blown part at first appeared to be a transistor, but apon closer inspection, I see it has 4 legs ... 2 on one side and 2 on the other but they are offset. the number is
    <something>09. There is also a completely fried diode next to it. I say diode because the other SMT resistors are flat.

    Not only are the SMT parts hard to work with, the board traces are really tiny. You pretty much have to do all your work under a magnifying glass (with a lot of light). I would like to get some practice on SMT though.

    When I stopped doing this for a living, everything was mostly hole-through and only the special ICs and processors were SMT. We replaced them the old way. Now, I have hot air rework station so it would be nice to use that part.
     
  13. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,178
    2,690
    Jan 21, 2010
    I just stopped shaving. A #1 all over my face, and slightly longer over the top. The benefit is that it only needs to be done every couple of weeks.

    My wife did once suggest I got waxed, but I'll leave that to her ;)
     
  14. jmartin919

    jmartin919

    2
    0
    Dec 9, 2010
    Resolution?

    What did you end up doing to fix this?
     
  15. Tesla

    Tesla

    165
    2
    May 10, 2010
    I was unable to identify the small SMT parts so I could not repair it.

    I bought a new Braun shaver.

    Looks like most of this circuitry was moved to the AC adapter.
     
  16. davenn

    davenn Moderator

    13,260
    1,748
    Sep 5, 2009
    wax the face OUCH!!

    I get away with a full beard from easter weekend to labour weekend then shaved over the summer :)


    cheers
    Dave
     
  17. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,178
    2,690
    Jan 21, 2010
    Funnily enough, my wife asked that I stop shaving sometime shortly after that post.

    I now have about 6 months of growth and have been confused for a person of one of several religious faiths.

    Is this off topic yet?
     
  18. jmartin919

    jmartin919

    2
    0
    Dec 9, 2010
    My razor is a 10 year old 5416 that won't charge. I replaced the battery and shorted the bad fuse but it still won't charge. One side of the transformer reads 167V DC and battery voltage on the other. I put 1.5 volts across the green charging LED and it won't burn. At this point I think I'll just buy a new circuit board (with shipping $34). I know it's an old shaver but it works (worked) great and I just replaced the cutter block and foil - plus it was made in Germany. Don't know what to expect from a new shaver these days.
     
  19. beckjm

    beckjm

    1
    0
    Oct 29, 2018
    Just wanted to say thanks for the link to the site for the replacement fuse. I've already replaced the rechargeable batteries on my unit, and the circuit board is now unavailable, so replacing the fuse is the only thing left to do. I'd really like to hang on to my shaver - old as it is. Fingers crossed!
     
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