Digital Dash going hay wire - Honda Prelude Forum

shift_of_legend · 12-11-2007, 09:13 PM

94 Honda prelude h23 engine...I think it was a swap before I got it a year and a half ago

it's half digital half analog
fuel and temp are digital

tonight while driving home red lines came up on it
I can still read the gauge but the red lines must be really bad
I think I also smelt something chemical...not like burning but almost like coolant but not

what can I do to fix it?
Should I pull the dash this weekend which is a few days away and see if any wires are shorted?

Is this a simple fix or do I have to replace the dash

petern101 · 12-11-2007, 10:56 PM

umm lets first start off how to write a proper question. its all jarbled and i really don't know what is exactly wrong.

its a 94 so you have to have EL gauges, is that going out?

fyi ALL 4th gen preludes have half analog / digital gauges...

shift_of_legend · 12-12-2007, 10:01 AM

Sorry for the garbled question I was panicking.

FYI there are preludes with full digital dashes. I found this out recently myself when a bunch of prelude owners who have never seen a half digital dash laughed at me when I said all preludes have digital dashes. My guess is the JDM versions have full digital. Go figure.

I'm not sure what EL means...I'll guess it mean Engine Light. Yes that is on and it's throughing a TPS code.

With regards to my Dash, things took a turn for the worst this morning. The red lines over the display were still there, but on the way to work the red lines disappeared, the gauge was displaying clearly and then a minute later it went black then smoke started coming from the dash. So that confirms a short...So I'll be pulling down the dash this weekend.

92preludesi_TX · 12-12-2007, 10:34 AM

EL refers to Electro-luminescent. These are commonly referred to as digital but are still analog. All 4th gen (all prelude generations actually) have analog tachometers and speedometers because they use needles to indicate information. For instance if you had a digital tachometer, it would indicate in specific increments at what rpm the engine was running. An example of this is the S2000 tachometer and speedometer. In an S2000 the speed is given through a pair of 7 segment displays telling you exactly what speed you are going.

In the prelude, some models have analog tach and speedometer gauges that you can see all of the time, even when the car is off. Other modlels have the EL gauges which are blacked out and are mostly only visable when the car is on.

Now that that is cleared up...you seem to be referring to the temp and fuel level instrument display. If it has fried then you will probably just need to start searching for another one.

shift_of_legend · 12-12-2007, 10:38 AM

Damn it are you serious? It's not like a short circuited wire I can re-solder?

you are probably right about people confusing the EL for digital. I have never seen their dashes to confirm what they were saying was true.

Thanks for the explanation and patience. As you can tell I'm a noob

sean1121 · 12-12-2007, 11:12 AM

Quote:

Originally Posted by shift_of_legend

then a minute later it went black then smoke started coming from the dash. So that confirms a short...So I'll be pulling down the dash this weekend.

Quote:

Originally Posted by shift_of_legend

Damn it are you serious? It's not like a short circuited wire I can re-solder?

Nope, you let the magic smoke out, you probably need a new fuel/temp board.

shift_of_legend · 12-12-2007, 03:16 PM

How much do they cost

92preludesi_TX · 12-13-2007, 05:10 AM

Here's one: LINK

You can usually find one on ebay...and they don't go for much because they are all the same.

shift_of_legend · 12-16-2007, 06:37 PM

OK I pulled the display out today and took a few pictures.

I noticed a burnt diode and a capacitor that might be blown. I was going to do my own soldering but my friend has a friend who is really good at repairing electronics.

He'll do it for little or nothing and since it's already burnt out it's worth a try.

There is also a little burnt spot...you'll see it in the photos

This is the burnt diode near the power supply.

This is the Capacitor (far right) that looks swollen. Below on the brown controller board you see a little burn by Vin (voltage input)

shift_of_legend · 12-16-2007, 06:43 PM

More pics of the capacitor and burned area.

For those who might think the middle capacitor is swollen, it isn't. That's just a fat capacitor. The one on the far right has a bulge at the top. It's suppose to be flat or sunk down. That's where the 'X' groove is. If you look carefully it's raised. Usually that's a sign that the capacitor is blown. I didn't have anything to test capacitance. I tried to use my multimeter, but I couldn't get the probes in between the controller board and main circuit board. I was going to check for continuity. If the capacitor is good it should show the resistance increasing as the capacitor discharges or infinite resistance. If it is bad then it would show little resistance. At least that's my suspicion. I'm not an electrician, but I did electronics as my minor in college

petern101 · 12-16-2007, 10:39 PM

hmm that almost looks repairable. hey if your friend is going to do it for free why not?

but yeah, its just a simple fix to just replace

shift_of_legend · 12-18-2007, 08:54 AM

Trust me, I'd rather just replace, but I don't live in the states. If I order it on Ebay I'll have to wait 2 weeks at least before getting the part and when it gets here the duty and taxes will rack up big time. I figure I'll go with that option after repairing fails.

Besides, if repairing works you guys gain new knowledge and maybe some of you can go repair some old ones and sell.

Who knows

petern101 · 12-18-2007, 10:31 AM

^good deal

but i rarely see these go out. the CC goes out more than these do (from my experience)