need help with fixing a problem.
game will light up gi bulbs but wont boot or turn on score display leds.
score display leds have a faint glow.
strange noise is coming the speaker.
only changed fuses so far but no luck.

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the mpu/cpu board is brand new and the lamp driver is new too.
mpu shows is a solid green light.
squawk and talk board flashes a few times.
squawk and talk board and solenoid driver board are original .

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replaced all fuses.
f1 fuse blew after replacing them.

i will change the rectifier board next.
it does look like it may been worked on already on the left side of it.

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will this one work as a replacement?

also it looks like the bridge rectifier in a different place too.

will i need to solder anything to the board?

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unplugged J1 though J4 connectors and it still blew the f1 fuse.
so that narrows it down to the transformer or rectifier board , right?

i bought a power rectifier board and some more fuses so i will wait for that before doing anything else.

just got the new rectifier board.

taking out the old board but has wires attached to some bridge rectifiers on the side
but the new one won't need those , right?
i think someone already tried to rebuild the old board already.

also wondering about what the large plastic dome thing does .

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i am almost done installing the new power rectifier.

that power switch with the cover has a yellow wire coming from the right that is broken.
is that the ground wire and will affect anything the way it is?

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i dont know what to do now ....
i put in the new power board but nothing changed.
it still only lights up gi lights but nothing on the backbox.
before with the other power board it would light the mpu light
but now nothing in the backbox lights up
not even the score leds are dim anymore, they don't even come on at all.
i plugged in everything the way it should.

did i overlook something??

i think if it takes any more parts to fix it , i will just give up.

okay ..checked the tp points
voltage looks fine.
reinserted the connectors on power board and solenoid board.
after reentering the solenoid board connectors it showed a green light on the mpu and squawk and talk board

the mpu is a alltek mpu has shows green light stays on self test light and 5+v light on , no flashes.
squawk and talk board green light flashes 5 times and sw1 switch will play the sound effects if pressed.

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still no glow from the score led's .
maybe aux lamp driver board is bad ?

now its showing a dim glow on the score displays
like only one number is visible on each display.

going to test out the solenoid driver board next
fuse is good but need to check 5v transister next and the capacitors
can't tell if anything been changed on it already.

i have checked everywhere else but found nothing that could cause a problem.

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the voltages on the rectifier board look normal , shows the same voltage as shown on the tp spots.
not tried the solenoid board voltages yet.

green light on the mpu is not blinking on start up , it just stays solid green once it comes on.
it has 2 lights , one for self test and one for +5v but both lights lock on .

score display is not as dim but only shows one digit.

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that score display is the ball/credit display
the other displays show a faint digit but not bright as that one.

now i'm hearing some popping or crackling sound coming from the speaker on the pinball.

nothing happens when i push the reset button on the mpu.

voltages on solenoid board were:

11.5 volts for TP5

4.4 volts for TP1

based on the manual , thats a bit lower than it should be .

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i left the voltage meter in for a bit.

the voltage for TP1 slowly went from 4.4 volts to 4.5 volts after a few minutes.

the voltage for TP5 starts at 11.5 volts but levels out to about 11.2 volts after a few minutes.

try TP2 and TP4 next?

i need to solder the red wires under the capacitor
they were barley on and the on the left feel off while putting the multimeter on it.

not tested voltages yet but seems to be firing some coils now after fixing the wires.

the game still boot yet
still has no score displays

but it is working better than it was.

the mpu blinks now.
the test button on the door works and will fire coils and gi lights works and all playfield bulbs light up and flash.

mpu flashes 7 times
self test light goes off.
the row of 6 bulbs in the lower left corner of the backbox keep flashing 5 of the bulbs.
score displays flash some number on screen on for a moment when turned on but but don't stay on.

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not sure if this means anything
but it does like the score displays can light up.
it only flashed this for only a few milliseconds.

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the sw1 switch on the squawk and talk board plays sound but does play startup sound on boot.

the flippers work while in test mode.

self test fires the drop targets on the right side but thats it.
then it flashes a light under the play field 3 times that is under the out hole coil.
let me know what i should check next.

i'm going to take a break now.

great news!

after rebuilding the connections and cleaning them on the boards in the backbox
the solenoids now work and the sound works.

so now the only thing left is the display not coming on.
but besides that , it plays just fine.

cheeked solenoid board voltages

TP 2 measures 160 volts

TP 4 measures 250 volts

the voltage on the displays were the same as the solenoid board.

TP 2 = 160 volts

TP 1 = 5 volts

the close up shows the arrow on the hv pot is to the left.
i assume i will need to turn it to the right.
but i will turn it a tiny bit at a time to be safe.

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turned the hv knob a bit to the right.

the displays are at 182v but they still don't come on.
but that should be enough.

they have a glow around the edges but no numbers come on.

i'm a bit baffled here.
the displays do flash on for a millisecond on boot but don't stay on.

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i think it must a communication issue between the mpu and the displays.
they have power but i think they will not display anything if there is no cpu information received.

they does flash for a moment when a relay or something clicks at boot then they go off.

can't think of anything else to check now.

J3 connector looks to be in really bad shape.
i don't know how i could rebuild it.

i don't think should have 2 rows of holes on the connector , right?

i have noticed now that the score displays do flash or flicker a few times at boot.

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i did a memory clear ... no change

i will need to order a logic probe.

never used logic probe before
Where do i need to attach to test the logic of the mpu and the displays.

i think J1 plug on mpu is what gets the data for the displays.

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Well , if fixing the wires and checking the logic don't fix it then maybe all of the displays are bad.

does freezing temperatures affect score displays ? I had this pinball machine in a storage building for about a year.

i will take a break for now while i wait for parts.

i assume that the pin go left to right , so pin 15 would be this one , right?

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looks like jumping the tp3 to the did make some zeros come up.
the zeros stay on but don't change during game play.

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still not changed the capacitors yet.

there might be a chip might be bad

i reseated u3 chip and the zero's lit up and stayed on.
only one digit on the left is shown.
showed junk on screen at boot up.
score does not change.

yes , i jumpered tp3 to pin 10

tp1 jumped to pin 15 did nothing.

+5v led stays on
self test led is dim.

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the Alltek board was working when i got it about 2 years ago.

i never changed that chip.

it has been sitting in the my dads building for about a year.
he may have worked on it during that time .
looks he moved u13 into u1.

i will order the correct chip right away.

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while i am waiting for the ic chips to come , i am going to work on some the cosmetic details.
after testing the game some more i noticed that the ball gets stuck on mylar thats peeling up.
even on the the right inlane it can get stuck between the mylar and worn off play field but only if its moving slow enough.

how can i re-stick the mylar and what kind of paint to use to repaint the playfiyed?

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YES!
just put the u1 chip in and now the score works correctly.
the rest of the pinball is looking good too.

all thats left is repainting the in-lanes and fixing the mylar that peeling off on the left inlane.

what is the best paint to use?

how do i re-stick the mylar?

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