Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 22
  1. #11
    Bronze Member Roonabeck's Avatar
    Join Date
    Apr 2006
    Posts
    97
    Location
    Central MA
    Tractor
    Yanmar 1510 2wd

    Default Re: Thermo Start Light

    Usually the unreliable component that's most likely to stop working over time is a capacitor. Sometimes they explode which makes it easy to identify the problem part, but they can go bad without any obvious indication also. You could try de-soldering the two capacitors on the board and replace them with new capacitors of the same capacitance (measured in farads (F) or likely in this case microfarads (uF)). That's almost certainly more trouble than it's worth though, if the thermostart itself is still working fine.

    The little black box you soldered the middle leg of looks like a transistor, large enough to supply current to power something (possibly a light bulb).

  2. #12
    Elite Member
    Join Date
    Dec 2009
    Posts
    2,666
    Location
    gilmer tx
    Tractor
    yanmar 2002d

    Default Re: Thermo Start Light

    Roonabeck, you must be an electrical engineer. I wish I had a better understanding of electrical systems. You are right, after another inspection of my timer box I could see nothing physically wrong so I put it back together and will be satisfied that my thermostart works. Thanks for you comments.

  3. #13
    Super Member California's Avatar
    Join Date
    Jan 2004
    Posts
    5,653
    Location
    Sonoma County
    Tractor
    Yanmar YM240, YM186D, and another YM186D

    Default Re: Thermo Start Light

    Quote Originally Posted by Roonabeck View Post
    The little black box you soldered the middle leg of looks like a transistor, large enough to supply current to power something (possibly a light bulb).
    It looks a little cooked.

    I see C1881 K and the Hitachi logo on it. So maybe its this one:

    2SC1881K datasheet pdf datenblatt - Hitachi Semiconductor - Silicon NPN Triple Diffused ::: ALLDATASHEET :::

    Take a look at the six HTML pages referenced from that link.

  4. #14
    Elite Member
    Join Date
    Dec 2009
    Posts
    2,666
    Location
    gilmer tx
    Tractor
    yanmar 2002d

    Default Re: Thermo Start Light

    [QUOTE=California;3554298]It looks a little cooked.

    I see C1881 K and the Hitachi logo on it. So maybe its this one:

    2SC1881K datasheet pdf datenblatt - Hitachi Semiconductor - Silicon NPN Triple Diffused ::: ALLDATASHEET :::

    Your a amazing California. I do believe that is indeed the part. A little research shows I could buy a package of 2 for $1.78. Two problems, I don't know for sure that is the problem and biggest problem is I don't think I could successfully remove and install one on that circuit board.

  5. #15
    Super Member California's Avatar
    Join Date
    Jan 2004
    Posts
    5,653
    Location
    Sonoma County
    Tractor
    Yanmar YM240, YM186D, and another YM186D

    Default Re: Thermo Start Light

    Maybe take it to a TV repair shop? An electronics tech will have a small soldering iron that includes a suction attachment for getting the old part out without overheating the board. He could also analyze if the other components are working properly for the box overall to function as a timer.

    You might also look beyond the black box to see what overloaded that component. Maybe a dead short at the lamp. Or maybe the box is designed to time the lamp only, but it was mis-wired to carry the full load of the Thermostart heating element. Does the output of this timer run to a high-current relay which powers the TS?

    If the box only times the light and not the TS - I might ignore it. The earlier Yanmars had just an instruction in the manual: 'in cold weather use the TS for a few seconds'.

  6. #16
    Elite Member
    Join Date
    Dec 2009
    Posts
    2,666
    Location
    gilmer tx
    Tractor
    yanmar 2002d

    Default Re: Thermo Start Light

    Unusual for me, but I started thinking today about the bulb possibly being bad. I usually try to check out the unlikely first and then proceed to the likely. Although the filament in the bulb looks good I do not get any ohm reading across it. Should I?

  7. #17
    Platinum Member Scotty Dive's Avatar
    Join Date
    Feb 2010
    Posts
    809
    Location
    Ct
    Tractor
    Yanmar 2020D

    Default Re: Thermo Start Light

    Not sure about ohms, but I use the continuity setting across the bulb - thats where the volt meter makes an audible sound when a circuit is present
    Thanks,

    Scotty Dive
    Yanmar YM2020D "Git er Done Too"
    Pictures! http://s139.photobucket.com/albums/q...t=dfc00199.pbw
    Yanmar Tractor Database - Click Link, then click file and download the excel file.: https://drive.google.com/file/d/0BxR...it?usp=sharing

  8. #18
    Bronze Member Roonabeck's Avatar
    Join Date
    Apr 2006
    Posts
    97
    Location
    Central MA
    Tractor
    Yanmar 1510 2wd

    Default Re: Thermo Start Light

    Quote Originally Posted by California View Post
    It looks a little cooked.
    The only thing I saw that looked a little off in his picture was one of the leads on a diode (labelled "ZD2" I think) looked blue, as if it had become too hot at some point.

    Your suggestion to visit a TV repair shop is a good one, although I'm not aware of many of those existing any more around here. You might also try a local makerspace. Someone there might find it interesting to debug a 30-year old tractor circuit board, or might be willing to teach you how to do it yourself.

    Quote Originally Posted by winston1 View Post
    Although the filament in the bulb looks good I do not get any ohm reading across it. Should I?
    Quote Originally Posted by Scotty Dive View Post
    Not sure about ohms, but I use the continuity setting across the bulb - thats where the volt meter makes an audible sound when a circuit is present
    Zero ohms means continuity, and yes both indicate that the bulb itself is not burned out.

  9. #19
    Super Member California's Avatar
    Join Date
    Jan 2004
    Posts
    5,653
    Location
    Sonoma County
    Tractor
    Yanmar YM240, YM186D, and another YM186D

    Default Re: Thermo Start Light

    Quote Originally Posted by winston1 View Post
    Although the filament in the bulb looks good I do not get any ohm reading across it. Should I?
    Should be some very low number of ohms, maybe a fraction of an ohm. (Somebody verify this - I didn't understand Ohm's Law clearly 55 years ago in shop class and haven't thought about it much since. )

    That's after removing the bulb. You can't measure it in-circuit because that may also measure other circuit components at the same time - resolving nothing.

    A simpler test is remove the bulb and put 12 volts across it. Look at the bulb carefully and be sure it says '12V' before doing this!

  10. #20
    Super Member California's Avatar
    Join Date
    Jan 2004
    Posts
    5,653
    Location
    Sonoma County
    Tractor
    Yanmar YM240, YM186D, and another YM186D

    Default Re: Thermo Start Light

    Quote Originally Posted by Roonabeck View Post
    You might also try a local makerspace

    only thing I saw that looked a little off in his picture was one of the leads on a diode (labelled "ZD2" I think) looked blue
    Wow. So thats what kids and hardware-heads are up to in the present century. Fascinating!

    You're probably right, more likely ZD2 (or D1) which show some bluing, and are sensitive components. The bubbling on the IC could just be the lacquer visible everywhere on the board. An electronics bench tech would know in a couple of minutes of testing.

Page 2 of 3 FirstFirst 123 LastLast

Similar Threads

  1. Replies: 6
    Last Post: 12-14-2008, 05:21 PM
  2. Wait to start light won't go off
    By okie350 in forum Kubota Owning/Operating
    Replies: 2
    Last Post: 05-16-2007, 05:06 PM
  3. PTO light....won't start
    By daffyduk in forum New Holland Owning/Operating
    Replies: 6
    Last Post: 09-24-2006, 01:01 AM
  4. Oil Light is on and it will not start
    By Vernonator in forum Cub Cadet Tractors
    Replies: 11
    Last Post: 06-27-2006, 05:22 PM
  5. Thermo Siphon
    By atk_man in forum Kubota Owning/Operating
    Replies: 6
    Last Post: 11-22-2002, 07:34 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
© 2014 TractorByNet.com. TractorByNet is a registered trademark of IMC Digital Universe, Inc. Other trademarks on this page are the property of their respective owners.