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Blank speedo, corrosion damage help

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my speedometer on my 07' drz400sm w/ 3000miles, went blank the other day so I googled and found out it is a pretty common fix by opening up the speedo and resoldering a broken lead. Opened up mine and found a diode/transistor (I don't know what its called, circled in pic) if you know the name please inform me. I have been on the phone with Suzuki direct and they tell me I need to find a computer store for the part. I cant even solder it back on because the leads are gone/missing. In the pic I circled the problem in red. Please let me know if pic is too small.

Can be useful information for some people because it seems many people have problems with corrosion on the circuit board. Any help will be great!!!! Please save me from spending $900 on a new speedo

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Here's the circuit board damage. Upon opening speedo, corrosion covered that whole corner including the power wires. I removed every wire and hard wired them to the board after some electronics cleaner. All I need is that piece that broke off.

image.jpg

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Have you tried looking up a schematic for the board? That would tell you what component is needed to be there. Also, there's cheaper options to replace the speedo with, trail tech makes a replacement one for around $150.

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If you look right next to any of those surface mount components you'll see markings on the board, i.e. R54, C31, D10, T6, etc...  I have a decent amount of experience with electronics and building them. Usually Rxx or Cxx refers to Resistor # and Capacitor # (as in the # on the drawing/schematic not its actual value).  For example a schematic might have 5 resistors, so they'll be numbered R1, R2, R3, R4 & R5.

I can also guess that D refers to diodes and T is transistors (JFET, MOSFET, BJT). So my recommendation is to look right next to where that component is mounted and look for its reference, I think I see "D1" (meaning a diode).  Look at the top of the component and there should be some markings on it.  Then cross-reference those with a site like Mouser or Digikey.

Edited by bmwpowere36m3

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Looks like the pad on the right is missing, you might try cleaning it with alcohol, if it is missing, it can be replaced but would require specialized tools and chemicals( not sure if good old epoxy or super glue would work) and of course a donor pad with some trace (the smallish wire that goes from the board to the pad).. which the normal guy wouldn't have (basically you x-acto knife one from another board),  but some electronics shop might. and they could ID the component while they're at it.

 

I'd try to find some electronics repair person to look at it and tell you what they think. 

Edited by gfletch

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Thanks for all the help. Right now I will try and find a shymatic of the board. Keep in touch bmwpower

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Looks like the pad on the right is missing, you might try cleaning it with alcohol, if it is missing, it can be replaced but would require specialized tools and chemicals( not sure if good old epoxy or super glue would work) and of course a donor pad with some trace (the smallish wire that goes from the board to the pad).. which the normal guy wouldn't have (basically you x-acto knife one from another board),  but some electronics shop might. and they could ID the component while they're at it.

 

I'd try to find some electronics repair person to look at it and tell you what they think.

Okay, maybe I was confused by the OP's problem. Is the PCB pad damaged (the silvery tinned square under the component) or is the physical component itself damaged? If it's just the pad, first I'd solder the good end of the component to the board. Then on the other end of the component (damaged pad) I’d solder a short piece of fine wire (26-28 AWG) directly to it, with the other end of the wire to the trace that runs to the damaged pad. You’ll need to scrape a little of the coating off the top of the trace to expose the tinned trace (pale green line on the PCB that ran to the pad).

Also the solder job on the component directly below the damaged one (right-side) doesn't look that great. I would double check that one with a DMM.

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Okay, maybe I was confused by the OP's problem. Is the PCB pad damaged (the silvery tinned square under the component) or is the physical component itself damaged? If it's just the pad, first I'd solder the good end of the component to the board. Then on the other end of the component (damaged pad) I’d solder a short piece of fine wire (26-28 AWG) directly to it, with the other end of the wire to the trace that runs to the damaged pad. You’ll need to scrape a little of the coating off the top of the trace to expose the tinned trace (pale green line on the PCB that ran to the pad).

Also the solder job on the component directly below the damaged one (right-side) doesn't look that great. I would double check that one with a DMM.

 

 

You could try googling  "s1g diode" , i have no idea if that would be the part for certain, but hey if you're just giving it a shot... and I'd bet the missing pad is still soldered to the burnt one. I don't know if you could save it, but if I had to do it , i'd clean up both pad areas, maybe try the pad patch job first, then  glue the new component to the board, so not to stress the patched side and finish soldering it in.   I guess since its a "hope to save" it doesn't need an ISO certified pad replacement :)

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I will try the wire trick but I doubt I will get a good connection. What do you mean by the pad?

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the silver square on the board that its normally soldered to. there would be a small wire (so to speak) from the "pad" that routes thru the board that you have to find to repair the connection. if its still there but covered in gunk , thats good, you could clean it off and solder the repacement diode to it. if not, you'll have to fix it somehow.

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Good luck with a fix. I had something similar on my 2012 after 2036 miles. Tried unsuccessfully to fix it then just bought a vapor... With tach temp and every thing else I have no regrets I even bought a trick anodized red aluminum bracket to mount it. Just get a trail tech vapor

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I think I will just get a vapor. Already spend about $40 for solder, solder remover and a solder.

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Dr.d, that's really clean looking. I like how it incorporates the turn signal lights. Any write up on how to wire it all up.

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