2jzgte

Yeah it sounds lame but I cant see the dash in my LS400. It only happens on cold days (read; everyday now) and takes up to 1-2 hours for the black screen to illuminate. Right now I drive the car by how fast I think I'm going because I can't see anything. It does however tell me what gear the tranny is in, but nothing else. Why is the dash display disappearing like this? I know it's not the bulbs and electrical system because it was already checked.

pscmj

This is a common problem on the 1st gen LS. There is a great thread on this issue here on CL from back in early February. In most cases, the problem stems from aging electrolytic capacitors on one of the instrument panel circuit boards located behind the gauge cluster. As these capacitors age, they lose their ability to charge to the appropriate voltage levels quickly (and eventually not at all), especially as temperatures fall. Part of the circuitry on these boards converts the system 12-16 VDC to much higher supply voltages for the actual florescent displays on the instrument panel, and the electrolytic capacitors store these voltages. As the capacitors begin to fail, they will eventually charge to proper levels, but not quickly, thus the no display- to flicker- to proper display scenario as the interior of the car warms on colder days. As time goes on, in my case from one winter to the next, the temperature at which the no display condition occurs gets higher and higher. Before I had mine replaced, I had no display at initial startup for any temps below 65 ... very annoying. Just as an FYI, I was a department manager for an industrial electronic circuit board repair department for over 5 years, and it was common practice for our technicians to replace ANY electrolytic capacitor over 5 years old as a preventative measure for the problem described above.

There a several options, the most expensive (and safest since the odometer memory is located on these boards) of which is to get the dealer to replace the boards. Another option is to remove the boards and take them to a “trusted’ local electronic repair shop (e.g. TV repair shop). CAUTION: These boards contain electronic devices that can be destroyed by electrostatic discharge and should be handled by the edges at all times, preferably in a statically controlled environment (if nothing else, at least touch a ground to discharge yourself prior to handling the boards). Anyway, good repair techs should know which capacitors are electrolytic (they are the tall cylinder looking devices located on the larger board of the two board set), and be able to replace them fairly inexpensively (including the labor for unsoldering the old ones and soldering in the new ones). Other options are listed in the referenced thread. Sight unseen, I went the expensive route, and had my boards replaced (I kept my old boards), but if I had it to do over again, I’d try capacitor replacement before board replacement.

Pianoman72

pscmj thank you so much for posting that. I kept saying it was the caps and nobody believed me. Of course you obviously know what you are talking about and I was just guessing so it's no wonder.

When my display goes out I'll know what do do. This needs to be in the DIY section in some form because it applies to all the 1st gen cars (i have a GS myself). It's not really a DIY but you do describe the steps people need to take and what they should tell their electrician. We still have a DIY section right, I haven't looked at it in a while. Anyway thanks.

hyperopt

I believe you man. It's the caps! And no...it's not Lexus defect. Caps are known to fail with age in many electrical devices. There are devices on the market that will test for fail caps in circuit. If you don't have one, just replace all the caps since parts and labor are cheap compare to a new board and you will be good to go for many more years. If and when my board failed, I will post detail procedures how to replace the caps and their locations all for free. Until then, I hope someone get to it before I do.

spxChrome

Mine started doing it today. File a complaint and lets get a recall! It takes 2 minutes to fill out a form and I have already been contact by a complaint worker for more information.

I have already submitted a complaint with the NHTSA and would incourage any of you reading this that have the similar problems to do so also. You can submit a complaint online here:

http://www-odi.nhtsa.dot.gov/ivoq/

A lot of cars get recalled for less dangerous reasons than this. This must not be tolerated, especially since this is not just a lighting issue that is problematic at night. We NEED the gauge lights to see the instruments in all lighting conditions.

pscmj

Hey Guys,

This has all been covered in the previous thread I mentioned, including contacting NHTSA. I'm not sure how to link to that thread ... but just do a search on "instrument panel" and you should be able to get to it pretty quickly. The title of the thread is "Instrument Cluster Circuit Board is Bad! $1000 bucks!!!". I've included below some responses from that thread that are very informative.

Anyway, as I said earlier, the electrolytic capacitors are beginning to fail on these circuit boards. It's not a matter of "IF" they'll fail, but rather a matter of "WHEN". Here is a list of components I would replace (or have replaced) BEFORE I replaced the entire boards. Note of Caution - as reinforced below, replacement of these parts should only be performed by "trained and experienced" personnel. I've seen many damaged circuit boards from attempts to remove and replace soldered electronic components by inexperienced technicians. The results can very destructive to say the least. If however you know (of) someone locally who knows how to solder and has the proper tools, replacement of these parts shouldn't take over half an hour to an hour.

Also, DON'T FORGET, THESE CAPACITORS ARE POLARIZED AND MUST BE INSTALLED IN THE CIRCUIT JUST AS THEY WERE REMOVED. Electrolytic capacitors WILL explode (more of pop really at lower voltages) if installed backwards, so care should be taken to note the polarity of the existing capacitors before they are removed. There is usually a colored band on the capacitor casing that indicates the negative (or positive) lead. Finally, these parts should be readily available from Newark Electronics or Digi-Key.

Here's a suggested list of capacitors for replacement - please proceed cautiously. Also, please note that this is only a suggestion. Replacement of these components most likely will NOT "fix" 100% of the boards, but should repair an overwhelming majority (IMHO). These parts are on circuit boards with a NIPPONDENSO P/N of 457952-1194 (from a '94 LS400).

Capacitors On the Large Board:

1) C105 820uf, 25v
2) C106 220uf, 25v
3) C107 820uf, 25v
4) C116 10uf, 50v
5) C117 220uf, 25v
6) C127 470uf, 25v
7) C131 100uf, 50v
8) C132 270uf, 25v
9) C133 180uf, 10V

Capacitors On the Small Board:

1) C201 470uf, 25v
2) C205 180uf, 10v
3) C206 470uf, 10


****************** Posts from the other thread ******************

I FOUND THE PROBLEM!!!!
YES!!! I found and fixed the problem with dash lights. Thanks to burghard. He sent his bad boards to me and I was able to troubleshoot and repair his and mine.

After many, many hours of exhausting and painstaking troubleshooting and reverse engineering (along with a little guess work) I finally found the problem. The problem I found is that some components have changed value over the years, specifically, several capacitors. These capacitors, along with some inductors form a tuned circuit. When the capacitors changed value, the circuits became detuned and damaged an IC (Integrated Circuit). All these components cost less than $20. However, all these components are "surface mount" devices of very fine pitch. It requires specialized equipment to desolder these components as well as to resolder the replacement parts. I do not recommend that your neighborhood electronics repair shop attempt repairs on these boards. The copper traces on the boards as well as other near-by components can be easily damaged if the proper equipment is not used. I do have the proper equipment and experience to do these repairs. I also have purchased a supply of the needed components to make the repairs. In addition, I am in the process of fabricating a test fixture for testing the repaired boards. My wife has objected to my continuing the use of her instrument cluster out of her car for this purpose.

If you want more information, email me at jwalker@cwia.com and I'll email all the info back.

Jim Walker


Hi,

Thanks to Jim Walker and Burghard, my dash lights are now repaired. I took Jim up on his offer to repair my board and the process went off smoothly. Here's how it worked.

1. I sent a payment to Jim on Paypal on Monday.
2. He sent me the boards 2 nd Day Air and I got them Wednesday.
3. My mechanic installed them today (3 hours labor) Thursday.
4. I drove home a happy camper and will 2 nd Day Air my boards back to Jim tomorrow (Friday) and he will return my core charge.

I actually got Burghard's boards (and his mileage) and someone will get mine after they are repaired. Jim commented in an email that it took courage for me to send money to someone I knew only by email but he appeared to be an honest and straight forward guy through his communcations and email so... I've been doing this on eBay for quite some time with few problems and for a lot more money and I think the people I have been dealing with have been very honest as have I.

I have given Jim's name, email, and phone to my mechanic on her request. There will be more work for Jim I expect.

Now the big test will be tomorrow AM when I crank up the Lex which has been sittng in the cold for 16 hours. I expect no problems and should "see the lights!!!!" (Note: I took the car out for a drive this AM and all lights worked perfectly)

Nice work, Jim.

Hank


Just wanted to let everyone know that Jim Walker also fixed my cluster circuit board. I had the usual symptoms of the cluster lights not turning on until the car warmed up.

Jim is also flexible. He allowed me to send my circuit board to him and then wait for it's return. This allowed me to get my board with my miles still in tact. Although this would appear to be risky sending someone your valuable circuit board and not knowing them, Jim is great with communications and eased any worries that I had. He even sends instructions on how to remove the board.

Bottom line is, Jim is a great resource if you want to get your circuit board fixed at a very reasonable price.

spxChrome

* footnote you have to send your circuit board if not then you will get the millage of the car the board came from and that would make an interesting story when you go to sell/trade the vehicle.

2jzgte

So what's this going to cost to fix? For a few thousand dollars my Toyota can have some new rims for Christmas. Should I just ditch the car? My parents have a long history of buying Lexus' and we always have a problem with one of them. I must say this was the last one I would expect to have any problems, that needed expensive repair, it's almost 10 years old without one problem.

spxChrome

well you have two choices of repair. 1st the ecu which is about $400 installed and if that doesn't fix it then the circuit board which is about $1500 installed. sucky part is can't tell which one is the problem untill you try it so I am going to try the ECU first - but if i were a betting man i would put my money on the circuit board.

Lextreme

How strange, my brother is a TV-VCR Repair tech for the Good Guys and he had a electronic shop before too. I took my LED to him about two weeks ago and he said he can repair it for me. I asked him how much would it cost if other Lexus owners want to repair it. He can do it with some profit for $200.