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Weird FT problems

cathaldub

Registered
1 10 Years
Joined
Feb 22, 2015
Messages
131
Location
Dublin, Ireland
I’ve a few weird problems lately with my FT

First up:
Recently the reel has been acting up, on doing a test both optos always test as closed, I can see the IR lit up with a camera.
Unplugging these from the opto board I would expect should trigger them to be open which leads me to believe a short somewhere on a board? All other switches in the matrix test good


Next:
The resistors on the flipper optos are scalding hot, all the time, even when not in use, they are burnt but actually still work fine, the 12v is reading at 15v on these 2 opto boards

Lastly:
There is an ever so slight static present, not noticed on gameplay but when machine is idle it’s there, I’ve recapped entire audio board, replaced ribbon cable, reflowed header pins on all boards, tested all speakers, reburnt roms, replaced the following just because I’ve a spare sound board here that’s broken so had the parts
u9(RAM),u10(YM2151),u11(ym3012),u13(cpu)


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I had an opto problem with my FT last year:

Strange Switch issue - Fish Tales
(I’m on the app so couldn’t paste the exact link).

Turned out to be a faulty IC that controlled those optos. Not sure if you have the same issue - but worth a read?
 
Thanks, I’ll look into the lm339
I’d have expected plugging that opto board out would trigger the sensors to be open but they stay closed at all times which is weird


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The voltage is correct at the flipper opto s
Resistors always get hot
I would just short out the receiver on the real opto board in switch test and see if it activates
Make sure everything is grounded nicely for your static noise
 
The voltage is correct at the flipper opto s
Resistors always get hot
I would just short out the receiver on the real opto board in switch test and see if it activates
Make sure everything is grounded nicely for your static noise

That’s good to know about the flipper optos.
Shorting the reel optos they still stay closed, never open.
Everything is well grounded, it looks like someone’s changed the amp on the soundboard before, so I’m going to reflow and tidy that up incase there is a short there somewhere


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Ok so no reel opto s
First thing to check is if you have 12v to the opto board
I noticed it has a colour display you would have to remove a 12v connector on the driver board to contact this maybe the playfield 12v connector has been removed to fit this and not been plugged back in or piggy backed
 
Ok so no reel opto s
First thing to check is if you have 12v to the opto board
I noticed it has a colour display you would have to remove a 12v connector on the driver board to contact this maybe the playfield 12v connector has been removed to fit this and not been plugged back in or piggy backed

I’ve it plugged into the 12v but the voltage at the opto is only reading about 1.2v for some reason


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I’ve it plugged into the 12v but the voltage at the opto is only reading about 1.2v for some reason


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Ok so this is my problem, weird, I was sure it measured 12v yesterday when I checked, must be a break in the cable, I’ll run a new 12v and see what happens


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The voltage across a correctly working opto emitter is 1.2volts. If it’s 12v then the opto is open circuit.

The other 10.8 Volts of the 12volt supply is to be found across the resistor in series with the opto.
 
Ah yea but I’m reading 1.2v at the actual 12v connector under the playfield and 2.2v when unplugged from the board[emoji1787]


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Thanks lads, was reading too much into it, Reel issue now sorted, was actually just a bad ground to that connector, I’ll have to trace that wire and see what happened it, yesterday I was using the cabinet braid as a ground when testing the 12v but today when I used the ground on the connector I was only getting 1.2-2v


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