Troubleshoot a F-14 - power board issues (updated)

[GeorgeB]

Picked up a good F-14 Tomcat last night, it powered up and played originally but now the GI (basic playfield lighting) comes up but the board doesn't boot at all.

What happened was we played about 5 games after getting it home and it had a few quirks, like the sound feeling like it wasn't complete.  After the 5 game, on the reset, the display and board went dead.  Tried to cycle the power, got a loud tone, recycled the power again and it was dead other than the GI.

Going to get fuses today, check those.  When I power up the machine the +5 vdc light is on and the Diagnostic and Blanking lights are out.

Any first steps I should take or repair suggestions?

Thanks!
George

[k7]

the basics? check for any corrosion from the 3 slot battery pack? pull the power harnesses to the CPU and clean the connctors. break out the digital voltmeter/multimeter.

Low +5 Volts Causing U10 PIA LED Error.
On a F14 Tomcat and other sys11 games, occasionally a power-on U10 PIA failure error is seen via the diagnostic LEDs, but the game still play fine after a sucessful power-on (the U10 error would happen spuratically). This can often be attributed to an issue with the +5 volts being too low, below 4.9 volts DC (check the +5/12 volt power supply filter cap, as this may be the problem). If this issue is not fixed, it can fry the special solenoid circuit and other circuits.

i purchased an F14 dead, and it didn't take much to get it up and running 100%, using help from the bible.

here's the bible:

http://www.pinrepair.com/sys11/index2.htm

[GeorgeB]

Pinrepair.com is the first place I went, trying to find my DMM is a different story though. 

Battery pack is clean, no corrosion, cleaning the power harnesses later this evening once my garage cools down.  Trying to get together a power supply for my worktable from an old computer one but I need the DMM to check the voltages 1st, then I'll be pulling the board and checking it.  Going to replace all of the fuses anyways on top of all that.

On another note, the playfield and cabinet are pretty nice.  I was thinking of putting Cliffy's in, upgrading to LEDs and upgrading the speakers as well.

Any tips on the LEDs?  Go with the 3 LED assemblies for the #44s or the single LED one?  Definitely going to substitute the flash type ones for the flashers.  Too bad there aren't ones for the domes.  And I started researching the speakers, just going to substitute in some appropriate ohm and size car speakers for the originals.

[k7]

there are dome LEDs, they are 89s. they look awesome.

just the fact it worked, but acted flaky, then failed to boot, really sounds like a 5 volt issue in my limited experience. 

use 4 ohm coax speakers for the backbox, and a 6.5 4-ohm woofer for the cabinet. it should improve the 20 year old stock in there now. F14 is a loud azz game if you crank it, really worth swapping the backbox speakers out of at the very least.

[GeorgeB]

Need to go buy a DMM and a Logic Probe since both of mine have disappeared over the 4 year period since I last had a pinball in the house.

Did a thorough visual inspection, someone has done previous repair jobs in there, can't tell the extent yet.  Figured out the volume was off on the music so that's hopefully one problem solved.

On the LEDs, the flashers take the #89 ones you linked (thanks!), the beacons take #1683.  Then there are the 64 #44 lamps on the playfield and then the #44s and #89s in the header.  Think I missed a few #44s too. LOL.

Can you replace the small right side speaker with a new one?  Or just focus on the left side one and the one in the cabinet?  Any suggestions on speakers that you've used in the past?

[k7]

i use car speakers, and i verify the stock ohms used and match it.

i use coax speakers only, so far i've used a german brand of 4x10's in phantom of the opera, a set of pioneer 5.25 speakers in 0geist's BSD, and a set of 5 inch sony's in 1 of mine, and a full 4.1 diamond audio component system in my MAME machine.

the coax speaker will give you good mid and high output, and they fire at the player, so that's good. wattage doesn't matter, because you're basically pushing a massive 9 watts of juice, or whatever a pinball amp produces...ha ha. triax speakers are a waste, imo. sounds will get muddy like they get out of the 3 inch cones some game manufacturers chose to use.

also, replace both backbox speakers, it's cheap to do and then you won't have 1 that over powers the other one. go to walmart, you can get 5 1/4 coax speakers currently for 24 bucks...if you're patient, you can get your choice of brand off of eBay for whatever price. i don't like the stock different sized speakers in the backbox...matching the pair cleans up the sound, and gets rid of higher notes only emitting from the right side, and louder muddy music from coming out of only the left side.

the woofer in the cabinet can be left alone if it's not ripped...that's the more expensive one to change out.

F14 is a fun pin with GREAT sounds, and i would have kept mine if room were not an issue.

[GeorgeB]

Thanks, I'm going to look into a pair of coaxial speakers and a woofer soon.

I was thinking if the powerboard has the C8 and/or C10 capacitor issue would going with a Rottendog replacement be a better idea than patching up the original board?  Sure its a cost issue but the Rottendog would be a reliable replacement.

[GeorgeB]

And I finally got a chance to get a good look at the power board:





Prior repair work was done to it, have a feeling the problem is there.  Have a Rottendog replacement board coming in - hopefully that'll take care of it.  Else the diagnosis continues.

[tktlwyr]

LOL!  That's just wrong!

[k7]

looks like your typical stock data east power board....ha ha!

[mrpinball]

That looks like the display high voltage section.
well it looks a bit hacked but actuily the SCR's in the display section are often NLA and need a substitute
that IS NPN as a PNP IS not availible or something like that[i just know ive had to do that same thing several times]