Secondary solenoids fuse keeps blowing - help!

[Mfresh]

My Roadshow has started playing up. It's fine for a few days, but then the next time I switch it on and start a game the ball won't launch from the trough and flippers won't flip. Opening the backbox I see that F112 Secondary Solenoids fuse has blown every time.

I'm not really sure what I should be doing to start fault finding this. Is this likely to be a stuck switch or a dodgy coil or what....

Any pointers gratefully reveived!

 

[Taxiturn]

My Roadshow has started playing up. It's fine for a few days, but then the next time I switch it on and start a game the ball won't launch from the trough and flippers won't flip. Opening the backbox I see that F112 Secondary Solenoids fuse has blown every time.

I'm not really sure what I should be doing to start fault finding this. Is this likely to be a stuck switch or a dodgy coil or what....

Any pointers gratefully reveived!

A few Pinside threads with possible issues to check:

https://pinside.com/pinball/forum/topic/roadshow-instantly-blowing-f112-fuse

wpc board keeps blow solenoid seconday fuse... why? | Tech: DMD era games | Pinside.com

| Forum Topic by boastaflow

pinside.com

Demolition Man blowing F112 fuse | Tech: DMD era games | Pinside.com

| Forum Topic by Zadom

pinside.com

https://pinside.com/pinball/forum/topic/tz-f112-blows

And this thread from here:

https://www.pinballinfo.com/community/threads/tz-f112-blowing.56954/

Seems a common cause is a connector being a pin out.

 

[strobey]

When the fuse blows, do you get solenoids energising immediately when you switch the machine on?

 

[drhex]

Does the fuse blow on switching the machine on or on starting a game? Good fuses from a reputable manufacturer?

 

[Moonraker]

My Roadshow has started playing up. It's fine for a few days, but then the next time I switch it on and start a game the ball won't launch from the trough and flippers won't flip. Opening the backbox I see that F112 Secondary Solenoids fuse has blown every time.

The symptoms you are describing are typical of a game with a motor (or motors in this case), when it stops in a certain position and then requires more umph (equates to drawing Amps) to get moving from being stationary. Your problem is that road show has three motors - Red, Ted and Shaker. I would hazard a guess that the shaker is the most likely culprit as it draws the most current. Just disable it - remove either J1 or J2 from the high current driver board that feeds the motor, then see if the problem remains or not. If it does remain then it's likely to be one of the other motors, which can be disabled in turn using menu settings.

 

[Mfresh]

Does the fuse blow on switching the machine on or on starting a game? Good fuses from a reputable manufacturer?

It's hard to discern when the fuse blows. The machine will work for a few days, but then I will turn it on and start a game and it is apparent that the fuse has blown. I don't know if the fuse blows before I pressed start or after.

 

[Mfresh]

Your problem is that road show has three motors - Red, Ted and Shaker.

Thanks for the advice Peter. I think there's even four motors! - Red, Ted, Bulldozer blade and shaker. Interestingly all except for the shaker motor are on a different fuse so they still work even when F112 is blown. Does that mean that none of these can be the culprit?

 

[Mfresh]

When the fuse blows, do you get solenoids energising immediately when you switch the machine on?

Well I just disconnected the shaker and replaced the fuses, and this time when I switched on all the flippers locked on.

I haven’t noticed this before because usually the machines are all switched on remotely while I am not in the room.

All flippers locked on is odd as it’s unlikely that all four transistors would fail. Might this be a fliptronocs board component problem. I will swap it out and investigate

 

[strobey]

Exactly what I was thinking when you said it only sometimes happens after power up... I think it's a blanking problem.

At boot the blanking circuit should hold the solenoids, flashers and DMD off because without the cpu running they can initialise in a random state.

That's not so bad for flashers and the DMD (you just see garbled noise on the screen and maybe some lamps on) but for coils they go full power on and with many at the same time it pops the fuse.

I'd gently push or reseat your ASIC as this is in charge of the blanking circuit and until the CPU has done its checksum, it holds all the board outputs safe.

Also reseat ribbon cables for same reasons.

 

[Moonraker]

Thanks for the advice Peter. I think there's even four motors! - Red, Ted, Bulldozer blade and shaker. Interestingly all except for the shaker motor are on a different fuse so they still work even when F112 is blown. Does that mean that none of these can be the culprit?

That depends on the fuse ratings and how the circuit is wired.

I had a similar problem on a highspeed 2 where it was fused but only taking out the secondary fuse, where in theory it should have taken out the primary and not the secondary but the fault in the circuit took out the secondary and left the primary intact.

 

[Moonraker]

This is where I ask for a picture of the battery area on the MPU...