MFD issues on '04/'05 Prius

Re: MFD issues on '04/'05 Prius

Ok, I've found a stereo store claiming total experience in dismantling the dashboard, guy said, prius? my favorite car, and i've found a computer tech who owns an 08 prius and whose mom has an 04 whose mfd failed whilst still in warranty and so dealer replaced it, but he said no problemo, he'd love to solder the thing, and i emailed him the link to hobbit's great treatise on mfd diagnosis and repair, and so tomorrow i'll be doing what you did. thanks.

one question, you say one can drive the car w/out the mfd but that "you need to reassemble the rest of the dash", hopefully that will be easy enuf to do, and then it has to be dessembled to re-install the mfd and then reassembled once again, right? hopefully that will not be too tedious for the stereo shop to do.

i'll let you know what happens next. (at this point guestimated cost is $50.)

 

Putting the dash together and pulling it apart is 10 - 15 minutes work if you take your time once you have done it a couple times. Apart from the screws holding the MFD there are only 2 others on the driver's side down low, the rest is clips, and click together wire harnesses.

 

Re: MFD issues on '04/'05 Prius

FYI, I just performed this cleanup to fix the problem, under this post by northwichita - search for "intermittent mfd display fixed cleaning circuit board" (I am unable to post URLs).

It worked great! The teardown, cleanup, re-install took under 2 hours. Give it a try if you don't have a good the proper tools to solder the connectors. Only tool required was a phllips screw driver, size 10 socket with extension, and the DeoxIT cleaner kit.

Readup and good luck, I will update if things break down again.

a

 

Re: MFD issues on '04/'05 Prius

Thanks fatdawg.

This is an important but very long thread. So it's worth pointing out here that hobbit's pioneering work and fix of this MFD issue is set forth in Post #46 of this thread.

 

Re: MFD issues on '04/'05 Prius

Thanks boo, hobbit's work is also quoted on the other link I mentioned, I give him full credit he's due, however, I also would like to give credit to northwichita for the cleanup idea.

 

Re: MFD issues on '04/'05 Prius

Well, here in San Diego, I found the stereo guy, the pc solder guy, in and out in one day...and it works fine! I paid about $60 altogether.

Fingers crossed it stays that way, thanks to this board, hobbit, patsparks and my prius

 

Re: MFD issues on '04/'05 Prius

Hi there, I live in Southern California, but the Long Beach area to be exact. Does anyone know anybody here that can fix my MFD problem as well?

Also, can you provide the contact details for the San Diego, stereo guy, pc solder guy that can fix this problem for me? Thanks.

 

Re: MFD issues on '04/'05 Prius

Nothing is as satisfying as doing it yourself, here is how.
Really, click here, it is worth the look.
Mine is still going strong near 2 years and 60,000 kilometres later.

 

Re: MFD issues on '04/'05 Prius

My repair is 18+ months old and going strong, uncross those fingers now.

 

Re: MFD issues on '04/'05 Prius

In San Diego, I used San Diego Car Stereo on Convoy, Christopher Doom, 858-569-0777 to R & R the unit, and West at Laptops Plus in Santee, CA at 619-596-2141,

art

 

Ok, I took the advice of the members here on the board and completely disassembled my MFD unit. The problem is:

I CAN'T FIND WHAT BOARD PIN 60 IS WHERE THE SOLDERING RE-FLOW NEEDS TO BE DONE.

Please help, I am using Hobbit's instructions and my car is literally in pieces. Which board does the repair need to be done to? I found a number 60 but it looks nothing like the one in Hobbit's pictures. Can somebody please help? Pictures would also be greatly appreciated. Thanks!!

 

It's a small rectangular connector in the middle of the board directly behind the LCD screen (the half that connects to the LCD screen board). The pins are very small and 59 and 60 are at one end of the connector.

My repairs only lasted a few months each time, so I ended up buying a newer used MFD on eBay for a little over $100 (the revised part number that fixed the connector problem).

 

Re: MFD issues on '04/'05 Prius

-------------------------------------------------------------------------------
Edit
The following lasted for me several months-- then my intermittent problems returned--
so I'm not actually recommending this anymore.
unedit

----------------------------------------------------------------------------------
I followed Hobbit's instructions preceding the 60 pin repair, which were to
A pass with DeOxIt and several plug/unplug cycles seems
to clean all this right up, though, so I wouldn't say
the connectors are outright corroded.

This is for the main connection between the two circuit boards.
I put it back together and has been running fine this last
month.

http://priuschat.com/forums/gen-ii-...-fixed-cleaning-circuit-board-connection.html

If you've already done this step then I just wanted to remind others.
If you don't see a break around that pin 60, perhaps it is somewhere else.

 

After I took apart the MFD display and literally strained my eyes just trying to find the microscopic pins, I decided to just spray electrical cleaner rather than taking the soldering route. I would rate the soldering job expert and by no means a novice leveled task. I would be much more comfortable having the board worked on by somebody who has experience with this issue and not just a random electronics shop.

I reassembled everything and so far so good, the electrical cleaner did the trick. As for how long it will last, only time will tell.

 

I'm wondering if the *real* reason why the combi meter display (The speedo, fuel gauge, PRND display, etc) fails is due to corrosion on one of the 4 connectors?

Folks have had the combi meter replaced, and naturally everything worked. I wonder if just disconnecting and reseating the connectors would have done the same thing?

I've had enough experience with that problem working on military electronics, especially communications gear, and industrial sensors in harsh chemical environments

 

UPDATE: I cleaned the connectors and the problem returned today. But what is interesting is that the problem only exists upon startup and only lasts for 30 seconds or so.

 

Re: MFD issues on '04/'05 Prius

Sorry to hear that, I guess the connections will need soldering and good luck to "permanently" cure the problem.

 

Re: MFD issues on '04/'05 Prius

Just had the problem on my '04 but with 157k miles I didn't think I would get any place at the dealer so I used Hobbits instructions to take it on. Dash disassemble was not too bad at all (done some of this before for lockpicks).

I used my camera to take this close up shot were you can clearly the the cracks. I made a fine point solder iron with a wire like Hobbit suggested and re-wetted all the points on this side. Worked perfectly.

 

Re: MFD issues on '04/'05 Prius

<edit> I need to learn to read peoples posts properly. What I have written below relates to the MFD not the combi-meter or upper display. Oops!<end edit>

I'm wondering if the reason people have had limited success with disassembly, clean and reassemble is because they are closing the gap in the cracked solder when reassembling? I suspect this to be the case. There is no doubt that the solder connection cracks. No point looking with the naked eye and no point running to the shop to buy your first ever soldering iron to repair this. If you have never done fine soldering before, a $1000+ part is not where you should be learning this skill. A tech skilled in repair of small circuit boards like those in laptop and PDAs will have the skill to do the repair. I saw mine under a microscope and the repair was beautiful. If your repairer does not have a microscope chances are he cant handle the repair. However just because he does have one doesn't mean he can though. I know a very crap mechanic with a full Snap-On tool kit!

Also be mindful of reassembling the MFD without putting any twisting loads on those plugs.

I'd wish everyone luck with this but it isn't luck you need, just a skilled technician.

 

In the case of the MFD, we know there is an issue with poor factory soldering. With the combi meter, we really don't know yet