(Topic ID: 101887)

Firepower down for the count. :(


By Arcade

4 years ago



Topic Stats

  • 41 posts
  • 8 Pinsiders participating
  • Latest reply 4 years ago by GoodToBeDad
  • Topic is favorited by 2 Pinsiders

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#1 4 years ago

We recently picked up a Firepower that is in great condition.
We managed to get it up and running and playing perfectly for about a week. Now, when we turn it on we get nothing but GI lights and even have the solenoid fuse blowing. Arrrrrgh.
Sound board test works great. but every time we turn the machine on it does something different. Sometimes it yells Firepower and kicks out a ball. Sometimes both red lights on the CPU stay on. Sometimes only the top light stays on, and sometimes both lights stay out.
Can't imagine what has happened.
Here is what has been done to the boards already and photos of them below.

CPU board.
1. All male pins have been replaced with new pins.
2. I have the new combo chip running from Hans so I have eliminated all the scanbe sockets.
3. Both lights on his board stay solid green for power and 5 volts.
4. TP 7 test a good 4.96 volts
5. New battery holder installed with lithium batteries.

Driver board.
1. Solder has been reflowed on the male pins.
2. New resistors installed
3. Brand new 40 pin interconnect has been installed, both male and female.
4. replaced a burnt transistor for the pop bumper coil.

Power Board.
1. All new cap kit installed in this board.

Any ideas are much appreciated. It boggles my mind that all this could have happened while the machine just sat idle.

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#2 4 years ago
Quoted from Arcade:

4. replaced a burnt transistor for the pop bumper coil.

If that coil was locked on when the transistor fried, did you replace the diode on the coil?

#3 4 years ago

You want to try the following:

1) With machine off .. pull the batteries. Wait 15 minutes and turn it on. See if you can get to boot. Shut the machine off and put the batteries in and restart the machine.

2) Re-seat the prom chips located in the bottom left of the CPU board.

3) Make sure the CPU/Driver boards are mounted tight to the backboard and to each other. You don't want any vibration to mess with that connection.

Mike V.

#4 4 years ago
Quoted from WOLF:

If that coil was locked on when the transistor fried, did you replace the diode on the coil?

Yes. We have the pop bumpers all working fine right now.
The coil that is locking on at the moment is the credit coil in the lower left of the cabinet.

Also RacingPin I will try what your said sometime tomorrow with #1.

However I do not have any chips on the bottom left of the CPU board. Those have all been combined in the one chip above now with the small daughter board that Hans sells.
I am positive that all the boards are screwed down tight as well. I never leave those screws loose.

#5 4 years ago

Have you checked all of your test points? Mine was having a similar issue with the LED doing random things when turned on. It ended up being a bad IC chip that was grounding on several legs. I got no signal or voltage at test point 2 which led me to the bad chip.

#6 4 years ago

Once you get it working again, consider moving the batteries to an external battery holder. Acid damage is no fun to deal with...

#7 4 years ago

Thanks. I have been sick recently and have not had time to mess with Firepower.
Is there a chart that tells what each test point should read?
I only knew about TP7 because of another tech thread that mentioned it.

#8 4 years ago

Ugh, what is going on with the EPROMs and cpu?

When I see stuff hanging off of an IC socket I have to think it is stressing out the physical connection. Has that cpu socket been replaced?

#9 4 years ago
Quoted from barakandl:

Ugh, what is going on with the EPROMs and cpu?
When I see stuff hanging off of an IC socket I have to think it is stressing out the physical connection. Has that cpu socket been replaced?

Yes. Brand new IC socket.
The board is the one that Hans made for all Williams games. It eliminates the need for all 6 of the scanbe sockets below and has all the code on 1 chip. Brilliant design.
Here is a link to what it does.
http://www.siegecraft.us/pinball/Firepower%20adapter%20instructions.pdf

#10 4 years ago

CPU P40 = High / 5v for reset
TP6 / CPU P36 = pulsing, probably around 2.5vdc. clock
CPU P5 = Pulsing around 2.5v. VMA

The data buffers at IC 8 and IC 9 fail quite often and i see them still installed on your board. Typically these are changed to jumpers by the time fire power came out. Check the inputs and outputs of these buffers. THey should have near matching signals.

The address buffers go, but much less often, still pretty easy to check with a logic probe. (pull everything but the CPU to check the address buffers, they should be pulsing with no software installed).

If all the checks out i would try and run the test rom at IC17 and see if it runs (you would have to remove the combo eprom from the daughter board). Also can pull the other socketed ICs to make sure they are not locking up the board.

Is there any jumper instructions needed to make that CPU/EPROM daughter board work? I see some kind of logic IC doing chip select of some sort.

#11 4 years ago
Quoted from barakandl:

Is there any jumper instructions needed to make that CPU/EPROM daughter board work? I see some kind of logic IC doing chip select of some sort.

It is a jumperless solution.
No jumper required.

#12 4 years ago

OK. I broke down and ordered a logic probe today. I've been really needing to learn how to do IC chips for awhile now and this should make finding bad ones easier.

Anyway while I am waiting on that to come in this Saturday, I took readings from all my test points on the CPU board in hopes that someone will know which ones are wrong and what may be the cause.
Here they are.

TP1 = 11.66
TP2 = 3.99
TP3 = 0.60
TP4 = .142
TP5 = 5
TP6 = 2.34
TP7 = 5
TP8 = 5
TP9 = 5
TP10 = .140

#13 4 years ago

Your blanking, TP4, not being all the way low is suspect. When the board is not running the blanking should be all the way down at 0v (i think?). Attach a meter to blanking and cycle the power a few times and see if it changes at all.

Typically blanking not being high is a symptom of a logic problem, not the cause. But since you have a funny reading I would check that circuit. There is a 556 timer, a transistor of some kind, 1uF and .01uF caps and the input signal going in.

You can kind of cheat to see if the blanking is bad. I would pull the fuses for the lamps and solenoids and watch the displays. Briefly jump +5v to the blanking test point. If the game boots, for sure blanking issues. If the displays show scrambled, blanking is not the issue (or only issue i suppose). I bet a lot of people would tell you not to do this, so i take no responsibility if something blows up =D. Blanking is kind of a safety check that blocks displays, lamps, solenoids from working if the computer is not running.

#14 4 years ago

I had similar behavior with the exception that after doing multiple tests it might start working again for awhile and then crazy random stuff. It turned out to be a PIA.

#15 4 years ago

I did all test with the game powered up. Surely the test are not done with the board off?
And I hold no one responsible for anything that goes wrong.

#16 4 years ago
Quoted from pinballlizard:

I had similar behavior with the exception that after doing multiple tests it might start working again for awhile and then crazy random stuff. It turned out to be a PIA.

Yes. I had a flaky PIA that I had to clean and resocket. Game played fine after that. Maybe it is out again.
Will my probe help with PIA chips?

#17 4 years ago

my issue was an AMI brand PIA. I hear they are trouble.

#18 4 years ago

A bad PIA or driver board issues could explain the blanking as well. You can remove the driver board and see if the MPU still is locked up.

#19 4 years ago

First, set DS1 switch 7 to off (its on in the pictures). DS1 is the top set of dip switches on the upper right of the CPU board.

Try running the System 6 CPU diagnostic and tell us what the LEDs do:

1) Turn the machine on and leave the coin door open.
2) Locate the diagnostic push button on the right side of the CPU. It is labeled SW1 and is the bottom of the 2 switches.
3) Momentarily press the Diag button. The LEDs should blink twice.

If they don't, tell us what they do when the machine is turned on and after pushing the diag button.

#20 4 years ago
Quoted from Schwaggs:

First, set DS1 switch 7 to off (its on in the pictures). DS1 is the top set of dip switches on the upper right of the CPU board.
Try running the System 6 CPU diagnostic and tell us what the LEDs do:
1) Turn the machine on and leave the coin door open.
2) Locate the diagnostic push button on the right side of the CPU. It is labeled SW1 and is the bottom of the 2 switches.
3) Momentarily press the Diag button. The LEDs should blink twice.
If they don't, tell us what they do when the machine is turned on and after pushing the diag button.

Awesome. I will report back

#21 4 years ago

Ok. Dip switch flipped and coin door open.
Looks like I may have real problems.
First of all the diag button never does anything.
Second the machine never boots in the same way twice as I put in my original report.
Sometimes no red lights at all
Sometimes both red lights stay on
Sometimes the bottom red light stays on
Sometimes the game yells Firepower
And sometimes it plays random game sounds.
Everything is very pot luck.
And just a few weeks ago it was playing perfectly .

#22 4 years ago

yikes...

How long was it working with Hans's daughter board on the machine?

Did you replace the CPU socket under the daughter board?

Did you change the jumpers when installing the daughter board?

Have you tried removing and reinstalling Hans' daughter board to see if there is a questionable connection on that socket? Carefully inspect the pins on the CPU and daughter board to see if any pins are bent/oxidized...

#23 4 years ago

It ran fine for about a week when the daughter board was installed.
The 40 pin socket the Daughter board is in is brand new. The pins on the daughter board are stiff and do not bend like an IC chips legs do. The original PIA sits on the top slot of this board and is easy to see that it is seated properly.
Not that those were bad ideas but I do not believe it to be my problem.
No jumpers were touched with the install as per Hans and the instructions.
Now, could the PIA on top of the daughter board or some other PIA gone out? Sure.
I will need someone with logic probe experience to let me know how to test these chips when it comes in.

#24 4 years ago

Remove the driver board and only have the top left power plug installed on mpu, see if the diag runs.

When things are crashed, you get erroneous diag results, the software has to be running somewhat for diag.

#25 4 years ago
Quoted from barakandl:

Remove the driver board and only have the top left power plug installed on mpu, see if the diag runs.
When things are crashed, you get erroneous diag results, the software has to be running somewhat for diag.

Thanks. I will check that after work.

#26 4 years ago

The reason I asked about the jumpers is something looks goofy with J3 and J4 in your pictures and the soldering on the adjacent chip looks suspect. I will compare it to one of my firepower boards and get back to you.

#27 4 years ago

OK.
Got home and removed the driver board and all the plugs on the CPU board but the top left.
Not sure which of the two top left plugs you wanted plugged in so I went with the Nine pin on the top left side and not the two pin plug on the top row left side.
So with just that nine pin plug installed the CPU board does the exact same thing as before and the diag button does absolutely nothing.

#28 4 years ago

Bump for fun.
And to find out if I had the correct molex plugged in on the above test.
My logic probe should be in the mail tomorrow so hopefully that can help figure out some problems.

#29 4 years ago
Quoted from Arcade:

OK.
Got home and removed the driver board and all the plugs on the CPU board but the top left.
Not sure which of the two top left plugs you wanted plugged in so I went with the Nine pin on the top left side and not the two pin plug on the top row left side.
So with just that nine pin plug installed the CPU board does the exact same thing as before and the diag button does absolutely nothing.

That indicates a MPU problem. If your blanking is still anything besides 0v or 5v, i would check that circuit. I think i the 1uf cap has caused me issues in the past.

#30 4 years ago

I looked at the jumpers on one of my boards and while yours is strangly wired, the electrical effect is the same, you have the standard jumper connected... so thats not it...

Quoted from barakandl:

Your blanking, TP4, not being all the way low is suspect. When the board is not running the blanking should be all the way down at 0v (i think?).

Andrew, his TP4 reading is the same as his TP10 (Ground) reading so I suspect his blanking signal is at 0 referenced to the board ground... I believe under normal operation, the blanking TP4 should measure 5V so 0V there could be because the CPU isn't running.... which in this case, blanking is working correctly.

The one that jumps out at me is TP2 at 3.99V. That should be at 5V unless the diag switch it pressed. Can you remeasure that one?

Did you replace the socket on IC13?

#31 4 years ago

Oh i misssed TP10 must be ground... Well there is a tenth of a volt difference in ground potential where ever you where picking up ground.

You need the test rom now to see if it runs at IC17 (or the daughter board? hans?). I would start suspecting the MPU PIA too.

Still think that daughterboard hanging off the cpu slow is not the best solution. The weight of it is going to flex that CPU ic socket.

#32 4 years ago

TP 4 now measures 5 volts.
TP 2 is still 2.99
Yes IC 13 has a brand new socket installed

What is the test ROM?

#33 4 years ago

Also my logic probe just came in the mail. (Elenco LP 560)
But as I have never used one, I will need a bit of instruction.
Which type of IC's are testable, and what to set the probe to.
I have two slider switches on it. One for TTL and CMOS and one for MEM and Pulse.

#34 4 years ago

Most of the time you are going to want to set it to TTL and Pulse. red lead on 5v, black on ground. Green is 0v, red is 5v. Yellow is pulses.

Find the Data buffers at IC9 and IC10. Check the input and output for matching pulses. On these buffers, one side connected to the CPU. p2, 5, 9, 12. The other side is p3, 6, 10, 13. A crashed buffer is a likely cause and a good thing to check with your probe. typically these are gone by the time firepower came out, probably because they caused so much problems. Yours are still installed.

This is going to be much easier to test using a bench top power supply.

http://firepowerpinball.com/downloads/CPULogicDiagram.pdf

#35 4 years ago

OK.
Since I do not have a bench top power supply I assume I can do this test with the game powered on and just the one plug on the top left connected?
(Connect the 5 volt to a known good TP?)
I have located IC9 and IC10.
I guess I will write down what each pin does and post here as I am still a bit confused on what is good to see and what is bad to see on the probe.
Sorry I am such a noob as logic testing, but I gotta start someplace.
From my limited experience I do remember that a couple of the end pins are usually ground, but I don't remember which ones or if that is always the case.

#36 4 years ago

Compare each side of the buffer. They should all be consistent on the probe. If you find one data line sounds funky or lights up your probe different it is suspect. A bad buffer leg will be distinctly sounding different than all the rest. The inputs should all sound similar. The outputs all sound similar.

I think Mark's pinball page covers these buffers well. Google mark's pinball and you should find it.

There will be good youtube videos on using your new probe too.

#37 4 years ago

Thanks. I'll check all that out before getting started.

#38 4 years ago
Quoted from barakandl:

There will be good youtube videos on using your new probe too.

Marks site is great.
But I have searched everything I can think of and every video on YouTube is completely useless.
Could not find a single video that showed how to use this device and none that were using them for my purpose.

#39 4 years ago

If he or someone else is still repairing these, it may be $65 well spent. lol.

#40 4 years ago

I have not had time to work on the game any this weekend, but just wanted to take a second to thank everyone who has posted ideas for me in this thread.
It is much appreciated and I don't always get the time to just thank people for helping out in their spare time for this great hobby.

#41 4 years ago
Quoted from Arcade:

If he or someone else is still repairing these, it may be $65 well spent. lol.

I can repair that for you. PM me if you want to swap information.

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