1. Join the Community!

    DSMtuners is a massive archive of DSM information - but more importantly, it's a COMMUNITY! Join in and participate with other DSMers, and invite all of your DSM friends to make this place their home. Chat with others, create a build thread, post questions and answers. Get involved! Logging in will also remove many of the advertisements, along with this notice. ;)

2G Gauge Cluster PCB Blown

Posted by spyderdrifter, May 31, 2020

Please Support ExtremePSI
Please Support ExtremePSI
  1. spyderdrifter

    spyderdrifter Freelancer

    4,888
    532
    Joined Jul 11, 2009
    Fountain, Colorado
    Anyone have thoughts on what would cause the PCB on the gauge cluster to blow out? I built my LED board and hooked it up the way I always have, and the flexible PCB smoked and burnt up in a couple spots. My LEDs still work, but the PCB is shot. No idea why, except maybe too many LEDs, but they use less power, so I'm a bit lost.
     
    Last edited: May 31, 2020

    2K  2

    1996 Eagle Talon TSi AWD
    awd · manual · 2G DSM

    2K  3

    1995 Mitsubishi Eclipse GSX
    awd · manual · 2G DSM

    2K  5

    1999 Mitsubishi Eclipse N/T
    automatic · 2G DSM
    Loading...
  2. TSiAWD666

    TSiAWD666 Supporting Vendor

    2,585
    770
    Joined Aug 15, 2003
    Herndon, Virginia
    Did you include in-line resistors with your LEDs to provide current limiting?
     

    Road Race Build 16K  15  371

    1999 Mitsubishi Eclipse GSX
    377 whp · 416 lb/ft · 2G DSM
    Loading...
  3. llxkevinxll

    llxkevinxll Proven Member

    390
    160
    Joined Jan 29, 2012
    Cleveland, Ohio
    Is it possible some traces were damaged during the Led install and caused a couple shorts?
     

    108  1

    1997 Chevy S-10
    rwd · automatic · Misc Vehicles

    Autocross Build 3K  4

    1996 Eagle Talon TSi AWD
    11.90 @ 124.05 · 2G DSM

    Street Build 1K  1

    1992 Mitsubishi Eclipse GSX
    awd · manual · 1G DSM
    Loading...
  4. spyderdrifter

    spyderdrifter Freelancer

    4,888
    532
    Joined Jul 11, 2009
    Fountain, Colorado
    Every LED has its own resistor.

    I think if there was a short in my board, it wouldn't work right.


    My guess is that maybe I have too much of a power draw from the cluster. I have the board powered by soldering the wires to 2 spots on the back of the PCB shown here along with the burned out sections.

    20200531_114600.jpg
    20200531_114554.jpg
     
    Last edited: May 31, 2020

    2K  2

    1996 Eagle Talon TSi AWD
    awd · manual · 2G DSM

    2K  3

    1995 Mitsubishi Eclipse GSX
    awd · manual · 2G DSM

    2K  5

    1999 Mitsubishi Eclipse N/T
    automatic · 2G DSM
    Loading...
  5. spyderdrifter

    spyderdrifter Freelancer

    4,888
    532
    Joined Jul 11, 2009
    Fountain, Colorado
    You can see what I built here to see the resistors and the rest of the wiring.

    PCB Front.jpg

    PCB Rear.jpg
     

    2K  2

    1996 Eagle Talon TSi AWD
    awd · manual · 2G DSM

    2K  3

    1995 Mitsubishi Eclipse GSX
    awd · manual · 2G DSM

    2K  5

    1999 Mitsubishi Eclipse N/T
    automatic · 2G DSM
    Loading...
  6. DogWhistle

    DogWhistle Supporting VIP

    617
    219
    Joined Sep 13, 2012
    St. Paul, Minnesota
    I’ve seen damage like that from over-voltage, but It appears to be over-current this time. LEDs vary in their characteristics, even out of the same batch, so some of those LEDs could be out of spec, per your load calculations.

    Also, the resistors, although limiting the current to each LED, still “draw“ current too.

    You could take the time to use an amp meter to measure the actual draw, but in order to reproduce consistent success, maybe leave the LED pigtails out of the back of the cluster housing, and use a scotchlock tap to bite into the harness wires, leading to the cluster.
     

    Drag Race Build 1K  3

    1999 Mitsubishi Eclipse GSX
    awd · manual · 2G DSM

    3K  6

    1999 Mitsubishi Eclipse Spyder N/T
    fwd · automatic · 2G DSM

    2K  0

    1991 Mitsubishi Mighty Max
    manual · 4G63t Swapped

    3K  6

    1996 Eagle Talon TSi AWD
    385 whp · 378 lb/ft · 2G DSM
    Loading...
    TSiAWD666 and spyderdrifter like this.
  7. spyderdrifter

    spyderdrifter Freelancer

    4,888
    532
    Joined Jul 11, 2009
    Fountain, Colorado
    This is the only part that would suck. I've been wanting these to be a simple plug&play unit so when other people order them, they don't have to send me their cluster first, or do any hacking of the harness. I'm gonna have to research more things to make this right without blowing the PCB in the process. Tapping into the harness is good as a temp solution, I think, but to get it where it needs to be, I need to do more.
     

    2K  2

    1996 Eagle Talon TSi AWD
    awd · manual · 2G DSM

    2K  3

    1995 Mitsubishi Eclipse GSX
    awd · manual · 2G DSM

    2K  5

    1999 Mitsubishi Eclipse N/T
    automatic · 2G DSM
    Loading...
  8. steve

    steve DSM Wiseman

    13,544
    664
    Joined Feb 3, 2002
    Boulder, Colorado
    How hard are you driving each LED?
    Assuming each is 20ma and discounting the power lost in each resistor, you have 23 LEDs on the main board and that's almost half an Amp being drawn. Get your meter out and measure it in your test setup. Plus your drawing it from almost the end of that the flex circuit.
     

    167  4

    2008 Audi TT 3.2 Quattro Roadster
    awd · manual · Misc Vehicles

    138  5

    2002 Audi TT Quattro Roadster 225
    awd · manual · Misc Vehicles

    148  2

    1992 Dodge Stealth RT/TT
    awd · manual · 3000GT/Stealth

    4K  12

    1991 Mitsubishi Eclipse GSX
    manual · 1G DSM
    Loading...
  9. spyderdrifter

    spyderdrifter Freelancer

    4,888
    532
    Joined Jul 11, 2009
    Fountain, Colorado
    What do you mean by "how hard am I driving the LEDs"?
    I've never really done testing of my LED builds, they all just sorta worked. I know that's not the right way to go about things, and I'm trying to change that.
    What would drawing power from the end do to things? The end of which circuit? (assuming you mean the oem flew circuit)
     

    2K  2

    1996 Eagle Talon TSi AWD
    awd · manual · 2G DSM

    2K  3

    1995 Mitsubishi Eclipse GSX
    awd · manual · 2G DSM

    2K  5

    1999 Mitsubishi Eclipse N/T
    automatic · 2G DSM
    Loading...
  10. steve

    steve DSM Wiseman

    13,544
    664
    Joined Feb 3, 2002
    Boulder, Colorado
    Simple, how much current are you running through each LED? I don't see any voltage regulation in your design so with a simple dropping resistor the current through the LED is going to vary and the cars electrical systems voltage changes from 12.6V down to 9V while cranking and back up to 14.4V while the alternator is charging the battery.

    Each LED type has a nominal forward voltage drop and a nominal operating current in it's specs and you use there values to compute the correct dropping resistor for a given system voltage in this basic circuit. What are your design parameters?

    As an example; A basic 5mm red LED has a Forward Voltage of 1.8V to 2.2V and a recommended forward current of 20mA. Assuming worst case voltage of 15V and a 2V forward voltage you would use a 650ohm resistor. Under those conditions each LED Resistor combo would dissipate 0.3W and consume 20mA of current. (0.04W for the LED and 0.26W for the resistor)

    If the voltage dropped to 12.6V the same resistor would only allow the LED to get 16mA of current and at 9V the LED would only get 10mA. This changes the brightness and helps with the current and power.

    In a parallel circuit like this current and power are additive. 23 LED's and resistors are 23x the 20mA current and 23x the 0.3W of power. 0.46A and 6.9W with most of that power being dissipated by the resistors dropping the voltage. These are the expected values and before connecting the circuit to your cluster you should measure them with your multimeter to make sure you don't have anything out of spec.


    Why does it matter where you connect? Each inch of the flex circuit has some resistance and the more inches you have (there and back) the more power is going to be turned into heat along it. In this case you exceeded the power handling of the flex circuit traces and they cooked.

    I'm not sure that drawing 500ma should have smoked the traces but I don't see an indication of a short in your display but the damage sure looks like there was.

    You can reduce the power usage by letting the LED forward voltage drop work for you. Combining 3 or 4 LEDs in series with a resister means it only has to drop the difference in voltage (15V - (3 x 2V)) / 0.02mA or (15V - (4 x 2V)) / 0.02mA (Assuming 24 LEDs, 8 or 6 strings of 3 or 4 LEDs) Each string only draws 20mA and the resistors are dropping much less voltage so their power dissipation goes down (8 x (0.12W + (9V x 0.020A)) = 2.4W or 6 x ((0.16W + (7V x 0.020A)) = 1.8W) # strings x ( LED Power + Resistor Power)

    If none of this makes sense I'll blame the lack of coffee this morning and old age.
     

    167  4

    2008 Audi TT 3.2 Quattro Roadster
    awd · manual · Misc Vehicles

    138  5

    2002 Audi TT Quattro Roadster 225
    awd · manual · Misc Vehicles

    148  2

    1992 Dodge Stealth RT/TT
    awd · manual · 3000GT/Stealth

    4K  12

    1991 Mitsubishi Eclipse GSX
    manual · 1G DSM
    Loading...
    DogWhistle and spyderdrifter like this.
  11. spyderdrifter

    spyderdrifter Freelancer

    4,888
    532
    Joined Jul 11, 2009
    Fountain, Colorado

    From this, it just means I need to go back and relearn all of this. Been years since I dealt with all that so it's all been forgotten. You might as well be speaking Russian at this point. Thanks for the info.
     

    2K  2

    1996 Eagle Talon TSi AWD
    awd · manual · 2G DSM

    2K  3

    1995 Mitsubishi Eclipse GSX
    awd · manual · 2G DSM

    2K  5

    1999 Mitsubishi Eclipse N/T
    automatic · 2G DSM
    Loading...

Share This Page

Support Vendors who Support the DSM Community
Boosted Fabrication ECM Tuning ExtremePSI Feal Suspension Fuel Injector Clinic Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications OHM Racing Raven Fabrication RixRacing RockAuto SouthBay Fuel Injectors STM Tuned Track Decals Track Sculptures VR Speed Factory