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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: BearTrap on December 15, 2017, 11:24:09 PM

Title: LED conversion
Post by: BearTrap on December 15, 2017, 11:24:09 PM: I'm converting my turn signals to LED by modifying the OEM chip. I cut off the pin 7 on the U243 chip and my results where not good. The right side signals work great but, when I push the left side, all four lights flash in hazard mode. Any ideas?

1990 K75
The last two photos in the PDF is my unit, the rest are instructions I followed. :dunno
Many thanks
Title: Re: LED conversion
Post by: BearTrap on December 15, 2017, 11:31:51 PM: I don't know why my post was not not complete. Anyhow. I tried the OEM chip mod by cutting off pin 7 on the chip and my results where; right side works but left side flashes all four in hazard mode. Don't understand...it should work.
Thanks again
Title: Re: LED conversion
Post by: Laitch on December 16, 2017, 12:10:35 AM: Quote from: BearTrap on December 15, 2017, 11:31:51 PM
Don't understand...it should work.
Post a photo of your work that isn't distorted.
Title: Re: LED conversion
Post by: BearTrap on December 16, 2017, 12:12:19 AM: I followed these instructions. The last two photos are my unit
Title: Re: LED conversion
Post by: Laitch on December 16, 2017, 12:18:01 AM: From what you have supplied, the image is either so large it's pixelated or so small I cannot discern where you cut, but I'm guessing you cut the wrong trace.
Title: Re: LED conversion
Post by: BearTrap on December 16, 2017, 12:20:52 AM: Try this photo
Title: Re: LED conversion
Post by: BearTrap on December 16, 2017, 12:30:20 AM: Another
Title: Re: LED conversion
Post by: Laitch on December 16, 2017, 12:56:58 AM: How did you manage to penetrate the board? I think your technique might have damaged the internals of the component and disrupted some of the surrounding circuits. It looks like you located the correct pin but it also looks like you dropped a grenade on it. :giggles
Title: Re: LED conversion
Post by: BearTrap on December 16, 2017, 01:04:07 AM: LOL. I desoldered the pin but you may be right. I'll have a closer look at the tracers and check for continuity in the morning. Have a used backup on order just in case. But it's the right pin, no?
Title: Re: LED conversion
Post by: Laitch on December 16, 2017, 01:21:52 AM: That's the right pin.
Title: Re: LED conversion
Post by: BearTrap on December 16, 2017, 01:22:26 AM: Thanks
Title: Re: LED conversion
Post by: rbm on December 16, 2017, 07:19:39 AM: I'm tending to agree with Laitch. The pin looks like it's been ripped from the plastic body. Moreover, when you desoldered the pin, did you use proper tools? Could you have overheated the chip in the process?

For this modification, it is sufficient to sever the PCB trace leading to the ground island with a utility knife, and leave the pins alone.

(http://i64.tinypic.com/352ezir.jpg)

P.S. To answer your confusion about the missing post, the text is there but very small in size. If you modify the post, then click on the toolbar icon called "Toggle View", you will see the markup tags. Remove the all tags for "size" and "font" and save the post. For some odd reason, the forum software adds these tags when one copies/pastes text in the edit window. Happens to me all the time. I think its a Mac thing.
Title: Re: LED conversion
Post by: BearTrap on December 16, 2017, 09:22:38 AM: Thanks for all the replies. I have another relay on it's way and I will be more careful with the replacement. Yes To all, I'm certain now that my haste has damaged the chip. Thanks again.
Title: Re: LED conversion
Post by: rbm on December 16, 2017, 11:07:00 AM: Don't discard the old flasher module. It can be reworked to make it operational again. If you want, I can look into doing that for you.
Title: Re: LED conversion
Post by: BearTrap on December 16, 2017, 11:24:40 AM: Thanks for the offer robert. The chip is available online so I will order one and fix this one as a spare or sell it on Ebay.
Abe