Gauge Cluster Circut Board

[killerFatty]

I have dissasembled the gauge cluster down to the boards and was wondering if anyone knows what transistor or circut actually needs to be replaced in order to fix the back lighting issue. I remember a thread on club lexus I believe that talked about it, but I have searched both forums and can't find anything. I attached pics of the boards if it helps and my dissassembly line.

[OmarG]

Just find the number :)

lawbut2468 quote from clublex

"I've re-read all 18 pages of posting. Lots of useful info. Here's my take on the instrument cluster problems:

1. dash has no light when cold. light comes on after inside of car has warmed up - replace C212

2. fuel gauge irregular movement (not moving, sluggish, slow, etc) - replace C142

3. stuck needle(s) - tach, speedometer - this is likely a mechanical problem, open up the whole instrument cluster and examine the back of the tach and speedom and use a Qtip with a light solvent to clean off any noticeable sticky substance.

final note on the cap ratings. the cap is very susceptible to heat. over time, the electrolyte inside the cap dries up and its capacitance value changes (usually to a much lower value) when the temperature drops. the change in the capacitance value means that the timing circuits (oscillator and inverter) will fail to work. As the cabin is warmed up, the cap restores to its nominal value and the timing circuits work again. the repeated flickering means that the capacitance is getting close to its nominal value and the timing circuit begins to kick in and out. as the inside of the cab continues to warm up, the cap finally restores to its nominal value and voila, the timing circuit runs and the cold cathode light is finally on. If you live in the south where summer temperature are always in the 3 digits, you really need a cap with 155C rating so that you don't have to replace them again for years to come.

Thanks again to everyone who gave valuable info on solving these instrument cluster problem. The info has saved me a lot of time and $$$."

[killerFatty]

THX a lot. You are a life (and wallet) saver. I'll go to radio shack over the weakend to get the caps and have a computer shop or something solder them in. I can solder, and pretty well, however I want the capacitors done by a pro. I'll post my results and finished product as soon as I can.

[steve2006]

Print this off and take it with you. If you buy the capacitors get the ones rated at 105 degrees not the 85 degree ones.

[killerFatty]

Thx a bunch guys. I'll take that with me tomorrow when I go get the capacitors. How difficult is it to change them out. Do you think a computer shop would be the place to do it?

[90LS400Lexus]

3. stuck needle(s) - tach, speedometer - this is likely a mechanical problem, open up the whole instrument cluster and examine the back of the tach and speedom and use a Qtip with a light solvent to clean off any noticeable sticky substance.

I wonder if this also applies for inaccurate tach reading. At idle, in drive mine is usually pointing a zero!! It works, but is too low of a reading. <_<

[joebob1]

Thx a bunch guys. I'll take that with me tomorrow when I go get the capacitors. How difficult is it to change them out. Do you think a computer shop would be the place to do it?

I had mine done at a TV repair shop, it looked like you need to be pretty good with a soldering gun to do it. I gave the guy $30. Everything still works in very cold weather 8 months later.

[killerFatty]

where did you get the new capacitors? I tried radio shack and computer superstore place and they both didn't have the right ones. Does anyone know what happens if you have a capacitor with a slightly higher voltage rating?

[joebob1]

where did you get the new capacitors? I tried radio shack and computer superstore place and they both didn't have the right ones. Does anyone know what happens if you have a capacitor with a slightly higher voltage rating?

I found a local hobby electronic store. You should be able to find them online too. Search for capacitors in google. Also, like other people have said you want to purchase high quality capacitors.

[killerFatty]

I bought some on the internet. Here is the link. Tell me waht you think.

http://www.electronix.com/catalog/product_...products_id/590

[steve2006]

where did you get the new capacitors? I tried radio shack and computer superstore place and they both didn't have the right ones. Does anyone know what happens if you have a capacitor with a slightly higher voltage rating?

The voltage rating is not critical so 16volts to 25 volts, 25 volts to 35 volts and 50 volts to 63 volts is OK it is just the physical size which increases so be careful with the space available on the board.

The main thing is the capacitance is correct i.e. 10uF etc and they go in the correct way round as they have negative and positive connections but any decent radio shop will know this.

[killerFatty]

I got my capcitors yesterday and stopped by a computer shop today. Fortunetly or unfortunetly the boss/owner guy does gauge cluster repair for a local auto mechanic. What a coinsidence. The problem with this however is that he wants to charge me $100 to solder in two new capacitor even though I have the circuit boards already out and ready to work on. Do you think I should just pay him or find someone else that can work on circuit boards? What bugs me is I can pay $75 on ebay to ship the whole gauge cluster, have it dissassembled (30 min of work right there), new caps. soldered in, reassembled and shipped back with a three year warrentee. The only reason I didn't do that in the first place was that I didn't want to be shipping a gauge cluster all around the country if I didn't have to. Plus I thought it would be cheaper this way.

[killerFatty]

MY GAUGES WORK!!!!! :D :D I'm so happy!!! I had the caps. soldered in by the computer shop guy for $40. Then I reassemble everything. Put it in and now they work. The only problem is that in the 2.5 hour process of reassembly, I let the gauge faces fall by accident about an inch on to the table. I snaped the tach needle, but everything else is fine. I glued the tip back on as straight as I could, and since it didn't light up anyway, I don't really care too much. I might take the gauges out of my spare cluster and pop those in, but I don't feel like another three hours of gauge cluster work.

[OmarG]

when i was first messing around in my 93's cluster i broke the speedo needle. i cleaned out the bulb and its clear now. I used clear scotch tape to reattach it. The light is defracted by the glass needle and moderately visible. I'll get pics soon.

[killerFatty]

thanks pics would be great. I tried to tape it at first but had little sucess, so I switched to glue. I'm used to a dark needle so its no problem for me. Do you know if it possible to swap a spedo and tach needle. They are the same size and I think I could do it because my other cluster has a good spedo needle.