Simplex 2001 Trouble

Hello everyone

I recently acquired a Simplex 2001 panel. I have this panel right now on my bench just trying to get it to a normal state. I managed to install the correct valve resistors for the zone card and NAC card and have everything clear, except the system trouble light on the 2001-1007 control is illuminated. There are no other troubles that I know of on the system (zones & notification circuits clear). Batteries are installed and charging circuit reading 27V. If I pull all the cards off the system and only have the control card installed, I still have the trouble. So I doubt my problem is one of the other cards. Either has to be something with the motherboard or the 2001-1007 card. I have nothing else connected to the panel, and terminals 1-6 on the motherboard have nothing. I have not figured out through my resources what (if anything) would or should be connected to terminals 1-6. Seeing as these are the terminals for slot 1, and nothing is connected, is this the cause of my trouble condition?

Any help would be appreciated. Thank you!

Do you have EOL resistors connected?

OP stated that they are.

There were several versions of 2001 systems. Is this a red box one row of 8 modules motherboard system, a black box two row of 8 modules motherboard system, or a full size system with multiple 4 module motherboards system? Answer this so I can give suggestions based on the panel version you have.

Yes, all end of line resistors are installed. The zone and NAC cards show no troubles, only trouble condition is on the control card. And if I pull all the cards except for the 1007 control card, I still have the trouble.

I have no history on this panel, so I don’t know if there was an annunciator installed originally and the panel is in trouble because it is looking for that. Although the “Annunciator Trouble” light is NOT illuminated, only the middle “System Trouble”. I received the panel clean, with no wires or resistors on any of the terminals. So it is impossible to tell what was connected to what terminals. I don’t believe I have a ground fault because the “Ground” light is NOT illuminated and I did remove the ground wire from the chassis so that the system would loose that reference.

I figure I have one of three scenarios:

1.) There is something supervised off of terminals 1-6 that I need to wire up appropriately to clear the trouble

2.) There is a jumper/resistor/diode that has to be cut or restored because of a missing component that was not given to me or not aware was installed on the system (annunciator for example)

3.) There is an internal fault with either the 1007 control board or motherboard (maybe a charger fault) that is causing the trouble light to illuminate

Red box, one row with 8 slots for cards.

OK. Here are a few things that can cause a system trouble only.

If the system had a remote reset there is a jumper on the -1007 module between solder pads 3 & 4 that is cut. That is a normally closed connection which comes out to terminals 2 & 3 on TB-1. If the jumper on the control board is cut, install a jumper on TB1 between 2 & 3.

The battery harness should have a jumper on the plug between pins 1 & 2. That supervises that the battery harness in plugged in.

Check the voltage between system common negative and the cathode end (white band) of D12 on the motherboard. That should be around 45 volts. If that is low it indicates that C3 needs to be replaced.

Thank you for your help

Checked the jumper, nothing cut on the card. And the battery harness has the jumper installed between Pins 1 & 2.

So here’s the strange part… I went to power up the system this afternoon to check the voltage off D12 like you said, and the system was normal! I’m going to chalk it up to a bad connection somewhere, possibly on the battery harness. Because I since yesterday, other then taking the cards out to get better access to D12, the only other thing I did was unplug the battery harness and check for voltage on the pins coming from the batteries. Maybe unplugging and plugging it back in cleaned up a corroded connection on the harness?

So the system is now normal, zones operate, and NAC give off 24V on alarm, so I think I’m good. Thank you!