Fixing digital dash

jvc1986 · 10-23-2009, 01:27 AM

UPDATE 03/11-09:
The problem was one small 1uF 50v capacitor on the card standing up, (card with 74hc14 IC on it) (sorry, forgot to take pics before installing).

Anyone tried to fix there dead digital dash?

Most of the parts are easy to get like resistors, capacitors, transistor, harder to get would be the display drivers and some of the more specialized IC's.

Mine is dead, all voltage in place, following the FSM tells me to replace the control unit, so looking for advice to what may be worth changing.

Even better would be a schematic for the circuit boards inside it, but proparly not available..

***DanNY*** · 10-23-2009, 09:27 AM

maybe swap a few caps...but usually the solder on the board loose up over time and it dies.

is it on/off thing or it's totally dead?

Hectic · 10-23-2009, 07:17 PM

Working fuel temp means you need to resolder the hot pins on the speedo/tach display. If they're both dead, or needs to warm up before both displays light up, then the MCU/power supply is defective and needs rebuilt.

burhan92SE · 10-23-2009, 10:53 PM

Quote:

Originally Posted by jvc1986

Anyone tried to fix there dead digital dash?

Most of the parts are easy to get like resistors, capacitors, transistor, harder to get would be the display drivers and some of the more specialized IC's.

Mine is dead, all voltage in place, following the FSM tells me to replace the control unit, so looking for advice to what may be worth changing.

Even better would be a schematic for the circuit boards inside it, but proparly not available..

u gotta open it up and test everything in there (if u r good at electrical)...otherwise just swap one from Junkyard...there's no info in FSM to repair the digi dash...

jvc1986 · 10-23-2009, 11:57 PM

For a little while I got the fuel and temp gauge to work, but all dead now.
Have resoldered all the display pins.

And, before the fuel/temp stopped working I heard a relay when pressing HUD on/off, but now it's no sound..

So I think the power supply failed on me, I'll have to check the components of it, and hopefully get it fixed.

Can I make a test rig that feeds it +12v and GND, or does it need other signals to just light up?

Stwodahorty · 10-27-2009, 11:40 AM

james has a page on HOW TO's, ill link it later.

jvc1986 · 10-28-2009, 08:59 AM

Would be great

jvc1986 · 10-28-2009, 02:54 PM

Now I did some more soldering, and powered it up with a +12v and GND only, and it worked, both displays light up!

Then I took it down to my car and installed it, and ofc it did not work, took it back in, still dead (but all the tiny horisontal and vertical lines in the speedo and temp glows faint red when power is connected)..

I'll let it warm up again and retry later.
Maybe because of temperature, its like +2 C out now.

jvc1986 · 10-28-2009, 05:01 PM

Did warm it up, looks like it comes back to life when heating the Control Unit, ill double check all solders there.

Any components typically to replace that can cause this?

*internetautomar* · 10-29-2009, 08:56 AM

if temperature is affecting it, it typically is a bad solder joint. I would just keep redoing them (after looking for obvious bad ones) until it all works.

jvc1986 · 10-29-2009, 09:12 AM

Tried changing the scmitt trigger, did not solve the problem.
Now it may seem like the real problem is in one of the capacitors on one of the "stand up" cards, when warmed up display lights up, when cooled down display turns off.

And electrolyte capacitors tend to go bad after some years, so ordered new one, gonna replace it on tuesday, will come back with a update then.