Need help with Jennings 400 Problem

[ucanwin]

I have a problem with a Jennings 400 5 coin, 5 line machine.
Here's the problem.... With the machine reset....Coin or coins in, pull handle, reels spin and stop properly, if payout.....pays out. Next attempt to put coins in.....will register only 1 coin, no more, pull handle, reels spin and stop normally, but reel motor continues to run and will not stop. If the board is pulled out and reinserted, you get one good play, and then, same as above. I have another working board, and it works fine. So, I know that it's a main board problem not the relay on the board behind the hopper.  I am not an electronic wizard, so I don't know how to locate the problem component. If I did, I can replace it. Boy, am I smart, or what? Ha!
Can anybody help an old, old man, with a lot of senior moments?????
Thanks.
Jerry

[ramegoom]

On the connector board (behind the reels) there are either two solid-state relays, or a PC board with TRIACS on it (I have both styles on two different -400 series machines). One of those controls the reel motor. The component may be defective, i.e. when it turns on, it won't turn off. If it's the TRIAC problem, look at the opto isolator that drives it; those tend to fail quicker than the TRIAC. If it's the SSR, you'd need to replace the entire module.

I'm kind of new to these as well. learning as I go.

[ucanwin]

Hi, and thank you for your reply. I believe that I have eliminated the board behind the hopper that controls the reels and the hopper.
I have a spare main board. When I put it into the machine, everything is all good, ha! So, I know that the problem lies somewhere on the main board, but I just don't know where to look yet. I am not good at electronics, but I can replace components if I knew what to replace.
Best regards,
Jerry

[ramegoom]

I recently found a problem and had a similar issue as the OP. The main board battery had leaked, and the acid leached thru the edge connector, onto the backplane board receptacle. Had to replace both backplane sockets, problem went away. Another problem I have discovered is the hopper connector that mates with the hopper. Those corrode and also lose their spring tension, causing erratic performance. Only fix is to replace them. At least those are still available, but you need to remove a terminal and drill the hole out to fit with the aligning post on the hopper end.

[ucanwin]

Thanks, for the tips. I think that I can eliminate the backplane board receptacle as part of the problem as my replacement board works fine. The problem is for sure on the main board. I'll have to look for the acid damage that you mentioned. Maybe there's a diode problem somewhere. I just haven't had time to dig into it. However, I would like to get that board fixed so I have a spare after I sell this machine. There is always one of those 400's that comes back to haunt after a while and a spare board can fix a headache.
The hopper connections have been a problem on almost all of the 400 Jennings machines that I have had. Usually, if you kind of move them around a little they will work OK. I know that is not a proper fix, but there are always other problems that are more pressing to take care of it seems.
Have a Happy Easter, and thanks again for the tips.
Jerry

[ramegoom]

This might help you find the culprit: