MJL v3 problem

van · Post by **van** » Tue Feb 23, 2010 8:21 am

As i am new here , HI to all .

I have a problen with MJL . It doesnt work any more . Car is pinto powered s7 , sitting in garage for some time.
When is started it last weekend , I saw that car is in limp mode . Connect PS to see what was wrong , but I couldnt .
Strip down case , and i found that voltage regulator doesnt work . Put another one , and i saw some low voltage figures . Vin is 5.5 V
and Vout is 3.95 v , also 3.95v on all components witch need 5v. Those figures looks low . MJL dont wont to conect to PC anymore .
What is the problem ? Am I fried something ?

Cheers
Stevan

NITROPIXIE · Post by **NITROPIXIE** » Tue Feb 23, 2010 7:31 pm

3.95v to the circuit components does sound a bit low and if your only getting 5.5v in then i would investigate why your not getting 12v in before going anywhere else.

I assume your power supply is good i.e. 12v. If you have a multimeter i would follow the power supply components from the molex connector to make sure you are getting 12v here to, then double check all of your solder joints of the power supply components. Hopefully this should source the problem with the power supply.

van · Post by **van** » Tue Feb 23, 2010 8:16 pm

I use to test MJL , at home , powered with just 9v battery . I was getting conection and MAP reading .
Now , when mesure voltage Molex connector pin on board , they dont show 9v . Actualy is 5.5 on 9v battery , and its 6.6 v on 12 v power from small ac/dc adaptor . As I understood , just voltage regulator , D2, D3 , D4 , D5 and capacitators C1 and C2 are responsible for power ?

NITROPIXIE · Post by **NITROPIXIE** » Tue Feb 23, 2010 9:17 pm

Hey Van

I have sent you a PM with a schematic diagram to help you fault find.

Ideally you will need to use a new or fully charged 9v battery for powering the mjlj which produces 9v. As for your 12v power supply i would say this is not adequate again if its only giving you 6.6v, plus it may not be rectified/smoothed enough.

I would use either a new 9v battery or a decent 12v battery so you get a full 12v when tested with a multimeter. If you have a desktop computer you can use a 12v feed from inside the case if you feel happy to do so. I did this on mine and had no problems.

Forgot to say in my first reply, welcome to the forum and we would be delighted if you could get some pictures up in our powered by section. Where are you from??

van · Post by **van** » Tue Feb 23, 2010 10:56 pm

Thanks for schematic .

Decided to remove all components of power delivery, and than I ll see what will be .

I am from Belgrade, Serbia .
My car isnt finish yet but its operational year and half .
I dont have many pics and videos of car with all components on it , http://www.youtube.com/watch?v=bEkM5Jy33XU .

Cheers,

Stevan

NITROPIXIE · Post by **NITROPIXIE** » Tue Feb 23, 2010 11:06 pm

Before you do just try a different and reliable power source first before you start taking things apart and confirm you are getting incorrect voltages.

Hope you source the problem soon. Nice to hear from someone in yur part of the world. Get some pics up soon.

Ryan

van · Post by **van** » Thu Feb 25, 2010 12:24 pm

Thanks Ryan

Odd thing is happening . I bought new voltage regulator and I soldered V in pin and Gnd pin first , connect new 9v battery . I saw 9v in pins , and 5 v on Vout . I soldered Vout pin to board . I check again , and voltage was 6v on Vin and Gnd . 3.9v between Gnd and Vout . I didnt try with car accu , but controler was working on 9v battery before .
IC1 and IC2 was removed due safety so no problem there .
What can cause this voltage drop ? Faulty Max232 ? Map ? Cristal ?
I check over , and over again , to see some bad soldering joints . Didnt find any .
Controler was working normaly for half year .
Should I call ghostbusters ?

Yvan · Post by **Yvan** » Thu Feb 25, 2010 9:32 pm

Perhaps your 9V battery is bad? If you have analog multimeter, set it to ~500mA and briefly touch battery terminals. It should jump fast to the max, and that shows that battery is good. Or just try with the car battery.

In Serbian:

Šta bi, spalio si paljenje?

Probaj lepo sa akumulatorom, čini mi se da sam negde ovde čitao da su ljudi imali problema sa baterijama. Pa tek ako i sa akumulatorom ne radi počni da čeprkaš i vadiš mu crevca.

Kako napreduje mašina? Ja jedva čekam da se ustali ovo toplo vreme pa da nastavim radove.

Ali o tome na našem forumu...

Pozdrav,
Ivan

van · Post by **van** » Sun Feb 28, 2010 5:48 pm

For a weekend I went to garage ,and plug MJL to car instalation . I started the engine but controler wasnt advacing ignition timing . It recives solid Vout 5v , and my user output LED , programed to switch on 4k , 5k and 6k rpm , are liting constantly. So ULN is working somethig , and probably microcontroler also do something . Still no connection to PC .I was watching schematic ,Max 232 is responsible for PIP signal also .
Could it be a problem ? Is it common to see max 232 not working ?
I resolder every joint , double check every connection .....

Post by **brentp** » Mon Mar 01, 2010 7:04 am

Does this only happen when the engine is running?

The testing you were doing before: can you communicate with controller using a fresh 9V battery?

van · Post by **van** » Mon Mar 01, 2010 8:47 am

Hi Brent
Nice to see you here

I did that , when controler was new . I tested connection with 9v battery. And evry thing was fine . Now , after a problem , i fixed voltage regulator , MJL doesnt communicat with PC , not on car 12v. Battery cant even deliver 5v to microcontroler . User outputs are doing some strange stuff. No spark timing .
Is it common to see fault on max232 ? My conclusion is that something is pulling to much power . I saw 200 mA on 9v battery , without microcontroler and ULN ( iI removed tham due safety ) on board .

Post by **brentp** » Mon Mar 01, 2010 7:11 pm

Hi Van,

Are any components getting warm with 200ma draw? what current draw do you see with microcontroller / and other chips removed?

van · Post by **van** » Mon Mar 01, 2010 10:14 pm

Hi Brent .

I saw 200 mA without microcontroler and ULN . Voltage regulator is getting warm , but not to hot for my finger . I dont know , but I think 50 C or somethig like that .
As I said , everything was normal , and one day I started engine , a MJL didnt wont to work .
I wont to put pad ( i dont kow is this corect term ) and new max232 . After that , I dont know what else I can do ...
By your expirience , I is it a common problem , or do I have very bad luck

Cheers
Stevan

Post by **brentp** » Mon Mar 01, 2010 10:20 pm

Sorry, it is not a common problem.

When you measure 200mA is this with the molex plug disconnected from the controller- so it is not connected to the car's electrical system?

Is the Max232A chip plugged in, or removed? Is the oscillator removed? If you can desolder and remove both, then test again, this may point to the problem.

It seems there may be a short on the board somewhere- finding where this problem is would be is the most important thing to do.

Let us know what you find out-

van · Post by **van** » Tue Mar 02, 2010 8:43 am

Thanks Brent for fast answer .
200 mA is draw from 9v battery to board without microcontroler and ULN . Molex was disconnected , only + and - pins were feed from battery . I replaced all power componenst ( voltage regulator , C1,C2 , D2,D3,D4,D5 ) .Didnt touch anything else , just resolder joints . I didnt put plug socket for max232 , but now I will . First thing to do is to remove max232 , test board , put new max232 . If that dont solve problem , than I will remove , oscilator and map , and go by building instruction and inspect everything .

Brent , can you tell me , what is common curent draw of MJL , when is just connected to power source ?
I will tell results , as soon as i do this .