MEP 802a No Start Condition

Good Morning Folks,

I installed an MEP 802a over the summer last year with an automatic transfer switch and remote start board from Inova. It's been working flawlessly. Well fast forward to yesterday, I live in Florida and the power went out (storming). I waited for the generator to start and nothing. I went out later to check it and it's like the front panel is completely dead. If you try and start it manually nothing happens. The panel lights won't come on or anything. The 7.5 amp fuse wasn't tripped. I checked the batteries they are fine (I can crank the motor easy using the service crank switch). Any help in tracing the issue would be a tremendous help.

Thanks,
Frank

View attachment 760489

Is the Dead Crank switch in normal position, and is the emergency stop button on the control panel potentially pushed in? I have run into this scenario on my MEP-803A previously, I had forgotten I turned everything off after a previous run to prevent any potential parasitic battery drains.

Open up the gauge panel, look on the back wall to the left and you will see the resistor board. Look at the 2nd to the bottom diode, it will say CR1. Check voltage on the right of the diode, it should be 24v and then check on the left side, it should read 24v. I bet it reads 0, if it reads 0 then the diode has shorted which is the cause of the problem. Temporarily you can bypass it with a wire, to see if it fixes it but it needs to be replaced.

Thanks fellas! Devilphrog I checked those switches it's all good. Jamawieb I will perform your diagnostic and see what gives. I'll report back on my results. Have a great day.

jamawieb said:

Open up the gauge panel, look on the back wall to the left and you will see the resistor board. Look at the 2nd to the bottom diode, it will say CR1. Check voltage on the right of the diode, it should be 24v and then check on the left side, it should read 24v. I bet it reads 0, if it reads 0 then the diode has shorted which is the cause of the problem. Temporarily you can bypass it with a wire, to see if it fixes it but it needs to be replaced.

Click to expand...

Shorted or opened?

Voltage on one side and not the other would indicate an open would it not?

Bypassing it with a wire would create a short across an open diode.

Farmitall said:

Shorted or opened?

Voltage on one side and not the other would indicate an open would it not?

Bypassing it with a wire would create a short across an open diode.

Click to expand...

You are correct.

Gentlemen,

Say it is the diode, what specifically would I need to get and where could I find one? My nephew is coming up this weekend and it might be wise to have one here if it ends up being bad.

Thanks,
Frank

Superfrank said:

Gentlemen,

Say it is the diode, what specifically would I need to get and where could I find one? My nephew is coming up this weekend and it might be wise to have one here if it ends up being bad.

Thanks,
Frank

Click to expand...

Get a 1N5406 or better yet a 1N5408 diode and be sure to install it in the proper direction. Any electronics supplier should have them, if not PM me your address and I'll send you a few, but you likely won't get them by the weekend.

Arrow will have it in your hands tomorrow with no shipping fee: https://www.arrow.com/en/products/1n5408/eic-semiconductor

Awesome! Thanks again!

Seems the link doesnt work properly... here you go: https://www.arrow.com/en/products/search?cat=&q=1N5408&r=true

Why don't you simply test it, before you get all wound around the axel, with finding something you might not even need. You can test it faster then write how to do it.

Update! Sorry fellas been really busy. I did everything jamawieb suggested. We checked the voltage, 0 & 24 just like he said. We jumped it temporarily with a wire, fired right up! When removing the diode be very careful as the ceramic or plastic insulator will break, don't ask me how I know. I guess when the put them in originally the wrapped the wire around the post before soldering in place. I guess we could have maybe cut it loose first and just soldered the new one in to avoid this. A little super glue and all is well. I lost power the very next week after the repair for 3 hours, our power coop isn't the best, the switch kicked it on and it ran the house flawlessly! Thank You jamawieb! You da man! I love this forum!

I'm glad it all worked out. I will usually just put another diode behind the original diode because of the brittle plastic.