I pulled a rookie move while replacing the coil to the garage and wired up the brown voltage lines to the wrong end of the diode don't ask... I'm really not usually this stupid and careless, really I'm not.

The whole set of low voltage coils is not working now, I replaced the F7 fuse, but still no 20v led light.

What else did I blow? I'm not sure what else needs to be checked and replaced. The bridge rectifier?

Thanks for your help

k, I figured that's what it must be. I'll replace that and see if things work.

Thank you!

how do I check a bridge rectifier? I've never messed with one of those before.

awesome, thank you!

Bumping this thread again. I've tested out the bridge rectifier (BR2) and it seems to test fine. :/

Neg lead from my DMM to the positive leg and pos lead to the AC legs, all good readings in the mid .500s. then red lead to neg leg and neg lead to AC legs and again, good readings.

What should I test next?

Thanks for the steps ScottSerpa. So, when checking the DC on BR2 between + & - pins, what should that read? also 16VAC?

Which pins are #6 & #7 on J17, do you just count them right to left, top to bottom like this:

1 2 3
4 5 6
7 8 9

Awesome thanks for that ref pic for J17, I hadn't found that anywhere yet. Curious where you got that from? Maybe I just missed it in the manual.

I'll test and report back. thanks!

Ok, I don't seem to be getting anything all the way back to the transformer. :/ Nothing across the AC legs on BR2 (nor on the +/- DC ends), nothing from pins 6 & 7 at J17 (wht/red and red/wht), and at white red combo at the transformer, nothing is registering either.

I can test a AA battery just fine, so I'm confident my DMM is in the correct mode (set at 20v when testing tho, not 2v like when testing a battery), I've done multiple tests, with neg/pos to the pins and then pos/neg. and I don't get any voltage readings on any of these points.

Does this mean the transformers been damaged or is there something else to check?

So, I've double checked again with the DMM set to 200v and still nothing.

I have a HDM-350 DMM like this one: (attached image)

Pasted image at 2016_10_25 05_19 PM (resized).png

Here's a better picture of my DMM. Sorry, I wasn't near my phone and DMM yesterday at the same time so that other pic was the best I could find off the internet.

So, I did some more research into my DMM and along the way I realized that I was checking AC current with my DMM set to DC :facepalm:

I do indeed have about 17VAC coming in fro J17 pins 6&7, but nothing across the AC legs of BR2

So, back to either having a bad fuse (which I've replaced already), a bad fuse socket or an open trace somewhere, right?

What's the simplest solution? a new I/O board?

IMG_20161026_074012 (resized).jpg

Wow, yep, you were right, I thought I had been careful removing the fuse, but apparently the top clips where too lose. the 20v LED lamp is now on.

I ran tests and all my coils are operating correctly.

Thank you for your patience!

Ok, had a long wknd and just got a new garage coil installed and am testing. I know I posted earlier that all coils were good, but I already figured the diode on the garage coil that was wired wrong was gone, so I tested all the other coils on the low voltage except that one as I was waiting for the replacement to arrive.

I got the new coil for the garage installed, but the garage door now stays open as soon as the machine is powered on. What's causing this? A transistor?

Thanks in advance.

ok, looking at the manual, it appears to be "Q20" am I reading that right?

Where can I find which type of transistor it is to order the correct replacement?

Looking through the manual, I believe this is where it lists out the part #, correct? (see image)

Pasted image at 2016_10_31 10_23 AM (resized).png

k, awesome, just making sure I was looking at the right thing. thanks!