drsessum
Hello, I have an older Guardian 10K Model #0044563 [image] .  It has been faithfully running, with the exception of the occasional battery replacement, for 14 years.  This summer it did not start an exercise cycle. There were no LEDs lit.   I noticed the 15A pop-up breaker had popped and it would not reset.  

I checked the battery voltage and it was 12V.  I replaced the pop-up breaker, only to find out later that it didn't control any critical circuits. There is voltage getting to the Main PCB on Pin 12.  The 15A and 7.5A fuse test good with a VO meter.

Am  I looking at a faulty PCB?
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78buckshot
12 volts is low for a battery that is fully charged or charging, you may have a bad charger. Make sure the battery cables are CLEAN and tight, that the battery has liquid above the plates, then with your voltmeter on the battery posts attempt to start it and read the meter.
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drsessum
I  just installed a brand new fully charged battery.  I was wondering if the PCB ever goes out on these things.  Everything else checks out and there was no problem before, other than having to replace the battery periodically.  I checked the switch and it is closing and opening normally.
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78buckshot
We need a little more detail, will the unit crank or start when you depress the manual switch, any sound, any movement? Even though the battery is new it could be discharged IF the charger is not working due to the pcb being live. With your meter leads on the battery posts and the switch in the OFF position read the voltage, now while making sure your leads are making good contact on the posts try to start it in manual and read the voltage, report back with your findings. You should see 13.2 vdc - 14.2 vdc with the unit at rest, if it will and while cranking you should see 10.5 vdc - 11.5 vdc.
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drsessum
Okay, the unit will not crank or start.  In the past when I had a bad battery, I would at least see the LEDs lit.  This time there is nothing.  The voltage on the battery is 13V.  THe unit will not crank.  I tested the switch after reading one of the posts.  The switch is good.  I checked the power going to the PCB from the battery to pin 12 and it shows 13V reaching the PCB.  Shouldn't the LEDs at least be on? 
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78buckshot
It sounds like you have the control disassembled far enough to check some items, yes you should at least have the green LED. Start at the F1(15 amp) control fuse holder, with a known good fuse in place you need to confirm battery voltage on both sides of the fuse holder with no voltage drop. The fuse holder has been a source of intermittent problems. Be careful as you have 120 vac coming in on N1 and N2 with some uninsulated connectors at the transformer, you also have battery voltage with enough ampacity to melt your probes so if your not comfortable with live circuits either remove ALL power or seek some help. If you read steady battery voltage on wire 15 in and out of the fuse holder the I would say the board is at fault.
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drsessum
Sorry I didn't get back to you right away. I did get a steady voltage on 15 right up to the PCB.  I ordered a new PCB, but that was last Thursday.  We had a huge wind storm Saturday night here in the NW and were without power for 18 hours.  I should have been more diligent back in the summer when I noticed the problem.
I'll be sure to keep you in the loop on this repair.
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78buckshot
10 - 4
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drsessum
Update:

First, thanks for the help 78buckshot.  I got the new PCB the Monday after the power went out.  Well, it gave me a chance to replenish other emergency items like oil for the oil lamps lol.

I got the PCB installed and as soon as I connected the NEG cable to the battery (-) the board LED lit up!  I pressed the Manual start and the engine turned over.  However, it didn't start. 

I went back to the forum for fail to start threads and found one that suggested checking the valve tappet clearance.  They were all around 0.005, so I set them to 0.003.  My model has a plastic type carb so I proceeded to check the choke.  It was fine. And, I was getting voltage on #14. 

I had tried tapping the top of the solenoid with the handle of a large screwdriver, having experience with solenoids in cars sticking.  That didn't do anything.  I sprayed some butane into the carb and the engine fired.  So I got something a little heavier to "tap" the solenoid, my favorite 20" crowbar.  I chose it mainly because it had the reach that I needed.  I pressed the Manual start and while the engine was turning over I wacked the solenoid a couple of times, and it started up.

I was immediately reminded of a scene in the movie "Armageddon" where the US astronaut was trying to get the shuttle engines started and the Russian cosmonaut  shoved her out of the way and started beating the hell out of the part all the time saying, "This is how we fix problems in Russian space station, because I don't want stay here anymore!"
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78buckshot
I find that when a unit sits for a few months and not able to run that the solenoid plunger sticks to the seat, I'm surprised that it didn't run on it's own after the shot of butane/either. What I normally see in that scenario is with a few seconds of running on either the plunger will release from the seat due to engine pulse in the fuel train, be careful with the solenoid, they won't take much rough handling. New plunger and solenoid from Ziller would be good to have on hand.
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drsessum
I wasn't as brutal with as the guy in the movie was with his space shuttle lol.  I've dealt with them before in Fords.  I will order a replacement solenoid.
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