digital speedo goner, should solder what?

[civiceater]

http://www.nissaninfiniticlub....45498

i know its been discussed ten million times...but at the end i still need help so from the thread above, i copied and pasted my last post:

bump!!! ok, NISTECH, i asked this question last year and it was cold so i wasnt able to get on it till today....now ive been reading up and down on all the threads about the "non-working speedos" now i came up with either its the radio that burned out the TCM? (is that right? its the small white box in the kick panel on the drivers side) well i took it out and pulled the circuit board, well it looks fine.... i might still go to the junkyard and get a new one, now next stop was the speedo input connector behind the speedo itself, i opened up the dash, pulled the cluster out, looked at the printed circuit board and it looks like new....no cracks or anything, however i did find one solder mound that has a hole in it but still have a good contact with the wire (should i resolder that?)...now i went ahead and pulled out the speedo itself and along came with the input connectors in the back, i looked at it and it seems fine, but one thing is bothering me, all the connections have brown stuff around the mound...is that the burn out? should i resolder that? (im not really sure what a burn out looks like so pardon me...) also you mentioned its either the control unit input connector or the cluster itself, now where is this control unit you're talking about? i got my whole car's driver side almost parted out....thanks for any input

al

btw, off topic, my hood hinge just snapped...well the driver's side, is it advisable to replace both? or should i just get one? thanks

[89240sxdude]

iv got a similar problem with the hud and dash lights only working when its really warm. also i dont know if its related but it has a nasty rev limiter when you stay above about 3200 rpms for over like 10 seconds then when it drops down it works normally again. i replaced the little white box (speed timer) with a junk yard piece but it does the same thing so i think it must be somthing else unless the new box has the same problem which i doubt it. im going to pull apart the dash when i have time

[NISTECH]

can you take a pic of the back side of the circuit board in the TCM and post it? The brown transparent circles around the solider mounds is normal thats called flux. the one joint with the whole in it , do you mean its cracked around the mound?? if so yes resolider it.

The hood hinge you can do just one.

[civiceater]

i actually took the liberty of getting some pics earlier....(on the 3rd pic, the hole is kinda fuzzy, but its the mound on the left) also its just a hole, not cracked or anything...

[NISTECH]

make sure all those phillips screws are snug. that solder mound would not be your problem. it would be on the speedo head it self. it comes out of that case seperately by 3 of those screws.

The TCM i dont see the typical trace burn on it. but I am curious about the silver trace runing from the connector pins to the transiter pins on the right side of your picture. can you get another angle of it?

[civiceater]

this is the speedo stuff apart, the most left one is the one on top of the board that the input connectors are on, and of course the top most is the input connector board and the bottom most is the speed lcd board....so which one do i need to solder again? this one is the board of the input connectors, well those brown stuff around the mounds for the connectors, are those the "flux" you were saying? or are those burnouts?this is another pic thats on top of the connector board and has the ground wire going out to the cluster assembly itself and of course this is the TCM a lot clearer, well fuzzy but a closer look hope this helps you to help meagain all efforts are greatly appreciated, thanks

al

[NISTECH]

Flip this board over and check the soldier joints of the connector I have circled. I assume thats the connector that connects it to the main harness and that would be the one that takes the most stress. It is usually the power feed or ground feed to the boards that has the joint problem. check those real close use a magnifying glass to inspect them for cracks.

[civiceater]

when you say "main harness" is that the wiring that goes from the LCD board to this board? because that's what you circled is. the input connectors that goes to the harness i disconnected from the car itself are the two paralleled rows going straight up and down on the left side of the pic by the screws...but ill be checking the other one as well...

[civiceater]

i just inspected them they all look good...no cracks or anything...now im stumped...besides swapping cluster and tcm what else can i try?

[NISTECH]

your gonna have to start doing pin out checks on the connectors to the speedometer assembly to be sure all the powers and gnds are there. that is about the only way to go at this point. Do you have a FSM on your car?

[civiceater]

yes, well not technically, i downloaded the S13 FSM floating around here...its for a 93, but they said its ok... what am i looking for?

[NISTECH]

all the power and grounds that go to the instrument cluster.at the cluster connectors. use a volt meter to check any wire that has voltage to it with the key on and check all the ground wires for continuity to ground. If all these wires test good you are likely looking at replacing the cluster to repair it.

[civiceater]

i was reading thru some forums across the net and i stumbled upon a question..does the speed sensor on the transmission actually have anything to do with the speedometer not lighting up? i mean back then when it was working the speed is some what still going cuz whenever it came back it would read what it should say like im driving down 35mph by looking on the rpm and then when it comes back it will say more or less 35mph..

[civiceater]

also if i were to swap it out with an analog, what would i need? i know that i would need a 91-93 cluster and the subharness, is this what i have?

[NISTECH]

No the pick up in the trans will not effect illumination of the speedo. yes that is a cluster and subharness on the table.

[civiceater]

is that all i need to do the swap?

[NISTECH]

I am not sure I myself havent done it but have seen several posts on it in 240 technical

[civiceater]

yea, thats what they're saying on the technical...

[89240sxdude]

i found the problem on mine its those two upright white panels on the bottom left of the main panel. i figured it only worked when it was really warm in the car so i narrowed it down with a heat gun and found the problem was in that area the problem is that those components r so small that u cant really do anyhting with it so i might take it to a specialist if i can find one that will