NFL Blitz 97 troubleshooting

jacklick

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Have a NFL Blitz that boots to blue screen. I checked the voltage and +12v was low @ 10v, which I assume the hard drive needs to spin the disks.

Anyway took the PS out to test bench. Adjusting the 5v adjustment pot caused power supply to shut down. Sprayed pot with some deoxit stuff and can adjust pot w/o shutting power supply down. Thanks Ken Layton...saw that in a post somewhere. So can can get +12 to @ 11.75 but the +5 is at > 5.5v which is too high.

Then removed the fan as suspected it was bad or at least needed to be degunked. With fan removed the PS is at 11.75 on +12 while 5.1 on +5.

I checked the caps with ESR in ckt and they appear to be fine.

Calling Ken Layton or other.
Any thoughts on why the 12v is so low?
Is there one cap specific to 12v I can try swapping out?
What voltage is supposed to be on blue wire? I am getting @ -8 to -9v dc.?
 
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blue wire should be -12. which isn't needed. white is -5, yellow is +12.

at that juncture where the voltages are all out of whack I encourage just replacing. most anyone will tell you that for the time and money and effort you put into fixing a power supply you could just get a new one.

though those box units aren't cheap like their screw terminal counterparts.
 
blue wire should be -12. which isn't needed. white is -5, yellow is +12.

at that juncture where the voltages are all out of whack I encourage just replacing. most anyone will tell you that for the time and money and effort you put into fixing a power supply you could just get a new one.

though those box units aren't cheap like their screw terminal counterparts.

Thanks for the clue on the -12v blue wire. I went back to troubleshooting and realize that it is basically adjusted simultaneously with the +12v.....both are low.

I don't mind just buying another one but this thing is in my crawl now though. Thought about putting an old pc power supply I have laying around. Unfortunately no -5v on the pc power supply I have.
 
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Went back and looked closer...seems c28 is the 2200uf 16v cap on 12v line. Replaced it even though it tested good and no change.

Maybe a resistor? I am done for tonight though.

one good thing. I removed the fan, soaked in simple green, rinsed and dried throughly....thing is whisper quiet now. Will have to do this on the AT supply in my Neo that sounds like a tornado.
 
In general, all the arcade duty switching power supplies have the +12v and the -5v track with the setting of the +5. There is no individual adjustment for the +12 and the -5. So if the +5 is ok then the cause of a low +12 would be the output filter capacitor on the +12v line. Probably a 1000 uf to 2200 uf @ 16v cap.

Sometimes the two main raw DC filter capacitors right off the bridge rectifiers go bad. Usual ratings are 100 uf to 220 uf @ 200 volts. Replace in pairs if one is found bad.
 
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Just an update on the power supply testing. I did buy a new AT power supply and bench tested it as a comparison to the original. It said must have min 1 amp test load to test power supply.

IMG_20141206_105255.jpg



so based on clues from another thread I connected a #555 bulb with 4ohm resistor. Didn't really notice anything change on this new power supply but the +12v was reading @ 11.5 or so when +5 was adjusted to 5.1. So figure it is common for +12 to be a little lower.

Then I use the same 1.5amp test load on the peter chou UP-150. Adding the 1.5 amp load to +5v doesn't do anything to my measurement of +5 (stays at 5.15) however the +12v is now reading @ 11.5. I remove the 1.5amp load and the +12v goes down to 10v.

Long story short. Test UP-150 Peter Chou power supply with a load. Looks like my power supply is ok so now to put into game.
 
Update: Power supply reinstalled and voltage adjusted to +5.05V at chip, power plug at HardDrive is reading @ +12.2V. At a minimum the fan needed to be cleaned and the adjustment pot cleaned so I could adjust voltage w/ out causing shutdown.

Checked and updated DIP switch setting (changed U8 SW7 from On to Off) so it game would at least do a post. No luck. Also tried U8 SW8 to On to force test mode but no luck. Can not get the board into test and just white screen on monitor.

Checked CPU LED indicator LEDs and LED 2,3,4 are all solid immediately upon power up.
Meaning = Processor Reset.

While in this state the HDD LED is off and the drive is not spinning. I removed the Hard Drive and hooked up to power source on bench. The drive does work or at least the disks spin and sound normal to me.

Checked all jumper settings and they appear correct. Only J11 p1-2 are jumpered.

Tested U5000 monitor with Craftymech TPG on medium resolution and it works fine.

Have board removed and going to try and check roms but have a feeling this (Seattle) board is having some other trouble.

Have I missed anything? Any other thoughts?
 
It could be the boot eprom, the board won't do anything without a good boot rom.

pulled the boot room (U32) and read it in GQ-4X. has checksum of 04F64B36. I have to find the rom now to compare.
 
Found version of blitz 1.2 and compared checksum of both sound and boot rom. Both checked ok

Boot Rom 1.2 chksum 04F64B36
Sound rom 1.02 chksum 007851c7

Board is clean with no damage so this is perplexing. Have it on test bench....ready to start using logic probe for first time. Feel free to guide me...will be a miracle if I make progress from this point.
 
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Long shot but does anyone know if one of the legs on this Fox040 should be pulsing? I would guess any crystal should but am way out of my knowledge zone.

The crystek next to it does pulse (beep, beep, beep etc) but the fox040 doesn't.

I can't find any schematics for these boards either.

IMG_20141206_185945.jpg
 
Checked and updated DIP switch setting (changed U8 SW7 from On to Off) so it game would at least do a post. No luck. Also tried U8 SW8 to On to force test mode but no luck. Can not get the board into test and just white screen on monitor.

Checked CPU LED indicator LEDs and LED 2,3,4 are all solid immediately upon power up.
Meaning = Processor Reset.

While in this state the HDD LED is off and the drive is not spinning. I removed the Hard Drive and hooked up to power source on bench. The drive does work or at least the disks spin and sound normal to me.

Checked all jumper settings and they appear correct. Only J11 p1-2 are jumpered.

Another update. Purchased an assumed working but untested seattle board w/ blitz 99 roms and hard drive. On bench w/ no hard drive the cpu LEDs 2,3,4 all flash as expected on power up. Hooked up to game and can at least get "power up test" post with this board.

sorry for crappy pic
IMG_20141210_183649.jpg


hook up disk drive and get further in the post sequence but then the game resets. So not sure if dealing with another board problem or hard drive is not of correct version to match roms. Next step tomorrow is to try 97 roms and harddrive with this new board.

IMG_20141210_184702.jpg
 
Another update. Purchased an assumed working but untested seattle board w/ blitz 99 roms and hard drive. On bench w/ no hard drive the cpu LEDs 2,3,4 all flash as expected on power up. Hooked up to game and can at least get "power up test" post with this board.


hook up disk drive and get further in the post sequence but then the game resets. So not sure if dealing with another board problem or hard drive is not of correct version to match roms. Next step tomorrow is to try 97 roms and harddrive with this new board.

put the '97 roms and '97 harddrive and it booted all the way up, can play a game. Nice!

Swapped the hard drive that was included with '99 board I purchased, and it boots up and plays as well. So looks like I have two working '97 hard drives, one working seattle board, and '99 and '97 roms and security chips.

Will probably order a 99 flash drive kit but not sure what I will do w/ the non-working seattle board.
 
I took a chance and picked up another "unknown" condition seattle board w/ blitz 2000 harddrive. It is not in great shape (had some bent pins, missing sound rom and one of dipswitches is destroyed) but it does work boot to test screen.

Since I had everything out and was going through this process for the 2nd time, figured I would make a video in case it helps others.

This video is focused on PCB led activity with various scenarios, failed PCB, HDD, no boot rom, no security PIC, etc. I am likely not 100% on everything but there is very little info on the LED behavior and even the manual is vague.




If I get really motivated, I might document how to image a replacement drive or compact disk or I might just spare us all and buy it from http://www.arcade-service.com/.
 
messed with these seattle boards some more today. Specifically a seattle board with Mace roms. First thing was the the led behavior was completely different on the MACE boot rom vs NFL blitz.

None of these boards came with a Harddrive so had to learn how to use chdman which wasn't as easy as it likely should have been. Thank goodness for KLOV.

1) make sure you run windows shell as admin or you get errors trying to extract .chd.
http://forums.arcade-museum.com/showthread.php?t=80788

2) I was having issues extracting @ 4gb logical chd image to a 8gb hard drive. it would just say extracting 0% and then just error out.
found this thread
http://forums.arcade-museum.com/showthread.php?t=266391

so extracted the chd to a raw file on local disk., downloaded a hex editor and deleted all the zero's at end of file....knocked down the size from @4gb to like 800meg. Then created a new chd file from that 800 meg raw file but used Cylinder, Headers, Sectors that equaled 1.6 gb.

extracted this new 1.6Gb chd file to hard drive and it worked like a charm. Not sure what the issue was, maybe version of chdman used to create original file or what.

I have some CF and adapters on the way and will likely do a video as this is easy once it is figured out but not w/o some bumps.
 
oh and forget to mention the blitz 2000 harddrive was toast. tried putting in freezer to see if it would spin long enough to create an image but was a no go. doesn't matter much but another trick I didn't know about before this.
 
OK new issue that I could use help on. I finally received some CF cards and adapters to try and get all 3 blitz versions (97, 99 & 2000) working as I have security chips for all of them.

I was able to get both '97 and '99 working with CF flash but not 2000. I then re-imaged the 8gb HD above w/ blitz2k.chd and still no joy. It goes through the boot sequence tests cpu,clock, roms fine and then blank screen and resets. I tested the blitz2k.chd in mame and it works (or the game at least boots etc)

? 1) I believe all the sound roms are the same for all games but if someone could confirm. The chksums and md5 hashes lead me to believe they are.
? 2) Is there anyway to verify the security PIC. Mine is labeled blitz 2000 but I am wondering if it is bad.
? 3) Beyond buying 2k upgrade, anything else I can try? the roms are all same size but are jumper changes required?
 
OK new issue that I could use help on. I finally received some CF cards and adapters to try and get all 3 blitz versions (97, 99 & 2000) working as I have security chips for all of them.

I was able to get both '97 and '99 working with CF flash but not 2000. I then re-imaged the 8gb HD above w/ blitz2k.chd and still no joy. It goes through the boot sequence tests cpu,clock, roms fine and then blank screen and resets. I tested the blitz2k.chd in mame and it works (or the game at least boots etc)

? 1) I believe all the sound roms are the same for all games but if someone could confirm. The chksums and md5 hashes lead me to believe they are.
? 2) Is there anyway to verify the security PIC. Mine is labeled blitz 2000 but I am wondering if it is bad.
? 3) Beyond buying 2k upgrade, anything else I can try? the roms are all same size but are jumper changes required?

I picked up a sandisk extreme 3 30mb/s card and extracted my modified blitz2k chd (shrunk by removing all the trailing zeros in a hex editor) and it boots and plays games.

However, I do have an issue w/ not being able to adjust settings as this thread did as well.
http://forums.arcade-museum.com/showthread.php?t=333726
 
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