MEP805B wont start

[thomas2831]

I have a mep805b that was running six months ago and blew a fan belt, since than it hasn’t worked. It cranks but doesn’t turn over completely. When I use ether, it turns over and runs off the ether but dies once the ether stops feeding it. My MPU is reading 0 volts and 2.25k ohms (currently ordering a new one), my electric actuator is receiving 4 volts, I checked j25 pin 9 has 24volts, j25 pin 8 is receiving 1 volt. I have replaced both the i/o module and the speed control module, but still receive the same results. I any and all help with trouble shooting to get it back up and running.

 

[Guyfang]

You wrote:
My MPU is reading 0 volts and 2.25k ohms
How did you test the MPU? IAW the TM? Or what?.

 

[thomas2831]

You wrote:
My MPU is reading 0 volts and 2.25k ohms
How did you test the MPU? IAW the TM? Or what?.

yes I tested it iaw the TM, received the new one and installed iaw the TM showing 1.5 VAC and im currently making sure the lines leaving the back plane to the mpu and electric actuator are good. I have been testing and verifying all relays and resistors on the inside of the DCS box.

 

[Guyfang]

You wrote:
It cranks but doesn’t turn over completely.

Can you explain it differently? What is compleatly?

my electric actuator is receiving 4 volts,

That's not enough. I normally adjusted the MPU to 3VAC. We found it seems to work better.

 

[thomas2831]

You wrote:
It cranks but doesn’t turn over completely.

Can you explain it differently? What is compleatly?

my electric actuator is receiving 4 volts,

That's not enough. I normally adjusted the MPU to 3VAC. We found it seems to work better.

the engine only cranks and only starts running when i shoot ether into it but once the ether runs out in the system it turns off


ok ill turn mine into 3VAC

 

[Guyfang]

Then test what you are getting at the electric actuator.

 

[thomas2831]

Then test what you are getting at the electric actuator.

just tried it and im still only getting 4 volts to actuator

 

[Guyfang]

The first few steps, compare them to your GCS. Also, when you changed the I&O. Where did you get the I&O from? A MEP-805B, or something different? I think there is a dip switch on the upper right corner for 15, 30 and 60 KW?

 

[thomas2831]

The first few steps, compare them to your GCS. Also, when you changed the I&O. Where did you get the I&O from? A MEP-805B, or something different? I think there is a dip switch on the upper right corner for 15, 30 and 60 KW?

ok I will try these steps tomorrow and I got it from someone off eBay that said it was working in December of last year. the next thing I was look at potentially replacing is the back plane since I checked the wires leaving the back plane to be good and the wires going into the back plane show good as well

 

[Guyfang]

Back plane $$$$$$$

@mciikurzroot Hey partner, Still have a back plane?

 

[mciikurzroot]

Back plane $$$$$$$

@mciikurzroot Hey partner, Still have a back plane?

Hi Guy. Yes I probably have a few [backplane board ] As we typically destroy these boards then put emm in the trash and get emm out of here and gone.. I will go out and look its about 5:15 PM here locally but still got some daylight, if this user thinks he needs one he can have it free, I am not about to take money for one because ? If the user PAYS for it hes gonna expect it to work and I am not offering any bit of warranty or TECH support, hence why we destroy them and toss emm in the trash.. Remember when we designed and built these now approaching 35 years ago, best i recall we went thru 4 revisions of the board and the set up and calibration of these boards is extensive did i say as well exhaustive and i doubt any SS members have the specs and or test set equipment to calibrate these boards, its not a simple process, I will add the new boards have no calibration points and simplify things a lot, no DIP switches or blinking lites to count and decipher... one board cross fits either the 30 or 60 and we now rate the 30 as a 45kw and the 60 as a 75 kw
good to hear from you : mac/mc MC II LLC

 

[Guyfang]

Thanks Mac!!!

 

[Guyfang]

Ball is in your court, Tom.

 

[thomas2831]

Ball is in your court, Tom.

ok I'm gonna run through those steps today with the procedures you sent me and if mac has a board he is willing to spare I would greatly appreciate it.
also do you have a schematic for the pins that connect the DCS module to the back plane so i can try and measure voltages and continuity for the connection?
also do you know where the governor control power relay is?

 

[Guyfang]

You do not have enough posts to send a PM. So if you want to get a hold of Mac, tell me.

 

[thomas2831]

You do not have enough posts to send a PM. So if you want to get a hold of Mac, tell me.

ok I will but first id like to try some different things to verify first so I'm not getting 24volts at all my connections on p25 on the I/O module and the ones that look like they feed over to P9 and P24 which I think is causing me to not get 24volts to my electric actuator. do you know how many ohms each diode is supposed to show when measuring with a multimeter? I think I have a break of 24volts some where in the system going from the battery to the modules and i'm looking at the electrical schematics and don't see a connection point between them.

 

[thomas2831]

You do not have enough posts to send a PM. So if you want to get a hold of Mac, tell me.

ok I just checked voltage going into the back plane and have 24 volts on the side(p5/6) going into the board but only have 24 volts in some spots on the opposite(leading to p24/p9) side but not all, do you have a guide for troubleshooting the back plane?

 

[Guyfang]

Take it out and install another on. That's what the TM says. Why do you think Mac and I hate these computer gen sets. There is NO troubleshooting for them. Haven't you read the TM's?

 

[thomas2831]

Take it out and install another on. That's what the TM says. Why do you think Mac and I hate these computer gen sets. There is NO troubleshooting for them. Haven't you read the TM's?

yea i understand your pain with all of this stuff and hate how the trouble shooting always ends with " contact higher maintenance personnel" but could you contact mac and ask if he has a back plane that i could have please

 

[Guyfang]

When you need someone, write this: @mciikurzroot
This sends a heads up to that person to look at this post. So when you post something now, he will see it.