Super Off Road (Track Pak) half screen FIX

DogP

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Hey,

One of the most common problems with Ivan Stewart's Super Off Road boards... seemingly the Track Pak in particular, is a problem where the track is shifted up by a half of screen (though you still drive the normal track). Several people had reported that deconverting the Track Pak board to the original Super Off Road fixed the problem, so it was related to the Track Pak chips.

The Track Pak conversion involves swapping around 24 chips (22 EPROMs, a PAL, and an EEPROM). So, the assumption is that the board itself is fine, but one of the Track Pak specific parts is defective.

I had this problem on a boardset 10+ years ago, and threw the board into a box... seemingly never to be found again. Well... I happened to come across it a couple weeks ago, in my attic! I have a working Track Pak cab in my basement, so I figured I'd try to track down the culprit.

The problem, at least in my case, was the serial EEPROM at U120. Simply swapping my good one into the bad board fixed it, and swapping the bad one into the good board broke it. I peeled the label off the good one, and found it's an NMC9346N, which is a fairly common EEPROM. I dumped it, but found that the contents didn't really matter to the game. It looks like the game will initialize the EEPROM as needed (so it's not a "security" chip)... but in my case, it couldn't write (or read) the bad EEPROM, which probably made the game freak out.

A big hint that your EEPROM may be toast is to look at the country list when you enter your name. In my case, I was given multiple options of Belgium and Australia.

I don't know whether the Track Pak conversions used a cheap EEPROM, which commonly fails (maybe even had a low number of write cycles and simply "wore out"), but comparing the conversion EEPROM to the 3 other Leland boardsets I had, the bad one was unmarked, compared to the marked NMC9346N on the other three.

Anyway, a suitable modern replacement is the 93C46B... available from Digikey for $0.28 ( http://www.digikey.com/product-detail/en/microchip-technology/93C46B-P/93C46B-P-ND/254225 ). You need to make sure to get the 'B' variant (64 x 16-bit), as there are 3 types... a 64 x 16-bit ('A'), 128 x 8-bit ('B'), and one selectable with a pin ('C').

The chip is on the bottom board, just below the connectors at the top. You can easily access it by disassembling the stack, though if you have small fingers and are careful, you can swap it by reaching between the board stack. Note the orientation has pin 1 facing down.

The EEPROM looks to hold settings, statistics, etc. (maybe shared with the battery backed RAM)... so after replacing the EEPROM, you'll want to go into setup and set your coin settings, clear statistics, reset the country selection, etc.

DogP
 

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A couple more pics.

DogP
 

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DogP - As a Track Pack owner thanks for posting this. I'm glad there may be an easy fix if I run into this issue.
 
Very interesting. I remember the weird country list. My U120 had 2 or 3 resistors bridging its pins, but I don't remember if that's on my original or Track Pak. Unfortunately I sold the board set for a 100 bucks recently.
 
My U120 had 2 or 3 resistors bridging its pins, but I don't remember if that's on my original or Track Pak.
Yeah, I've seen the resistor too... I'm guessing they used the EEPROM with the switchable x8/x16 on some (like the 'C' variant), and used the resistor to tie the ORG pin high to make it x16 (like the 'B' variant).

DogP
 
...

Thank you! Recently picked up a nice Super off road Track Pack and owner purchased a regular board set because there was an issue with his. He saves the old board set. I swapped boards to see what the issue was, had the weird track shift. I replaced the EPROM, reset it and it is working perfectly! Now I have two board sets!
 
Fian34,

If you found the information useful, you should give him a rep point. Hint hint, nudge nudge, know what I mean.
 
Bump a roo, Another Track Pack half screen saved, thanks Dogp. Mine actually crapped out at this year's SFGE show on the last day, but when I saw the screen I was like, that shouldn't be a problem I remember seeing a fix for that 👍
 
Sweet! Sucks that it broke, but it's great when it's a cheap and easy fix.

DogP
 
DogP,..... you're the man. I've been working on a Trak Pak, had the same issue (I'm pretty sure I've had ones do this in the past that I ended up selling the boards as broken!).

Anyways, pulled that eeprom off another Leland board I had (world series) popped it in and it came right up, fixed the problem.

Thanks for the tip!
 
My Track Pak Super Offroad displays a solid color for the bottom of the screen.

The way you describe the problem is that your track is shifted up vertically beyond the edges of the screen. Mine is oriented properly, but the bottom half is missing/red... and I think sometimes the top is that way too.

Different problem, correct?

I'll likely check out that chip anyways, all my country options are ONLY Australia...
 
That might be a different problem, or just a different way that it manifests itself. The country selection does sound like a hint that the EEPROM might be corrupted.

The first post has a picture attached showing what mine looked like.

DogP
 
I reset the country selection and it reset fine, so I don't think that is where my issue lies. Must have just been configured weird by somebody. I'll start another thread sometime today.
 
DogP I wanted to say a huge THANK YOU!! I followed your half screen U120 Slot EEPROM fix and it worked great, the game is playable again! I got the B variant ones from Digikey. My board had the resistors soldered on mine so I resoldered them on new chip, realized from another post this was probably unecessary and swapped to straight new B Prom. Fixed all half screen issues.
**Problem that happened at same time of split screen was I lost the Leland Tunes. I was hoping these would come back with new prom, they didn't.
So the issue I can't figure out now is the end finish line sound is clipped and delayed, and NO SONGS play during game, sounds for choosing car parts are slightly delayed. All other sounds work great.
I tried checking out U15T chip and reseated it, looked good, all audio tests passed too.
Any ideas?
 
I just picked up a super clean 3-player Track Pack cabinet this week. I could have sworn that it was working before loading in my trailer, but the seller had put the unit outside when I arrived, and was difficult to view the screen in the bright sun and perhaps I didn't notice the track shift issue then.... and I was too giddy that cabinet was so clean and the music was playing. Beginner collector fail! Anyway, it for sure is exhibiting it now that it is home as I can only choose "France" as the country, and then the track is shifted half way up the screen.

I'm a total noob at this restoration thing, but so happy to have finally found this thread. I'm placing the order with Digikey right now. Thank you!
 
I received the Digikey shipment on Tuesday, but didn't have time to work on the fix until today. It was surprisingly simple. After pulling off the riser board I was able to quickly locate U120, popped out that one (with the resistors soldered on) and put in the new one. When I first powered everything back up I thought I may have broke something as I no longer heard the music, but evidently the system had lost all the previously saved settings so I went into the service menu and turned "Attract audio" back on. Whew! I've attached a couple photos just in case others may be curious what mine looked like.

TB_Super_Off-Road_Track-Pak_3-Board1_U120.jpg TB_Super_Off-Road_Track-Pak_4-U120_orig_vs_new.jpeg

On a side note.... now that this issue is fixed, I've now encountered a new one. After playing the game for several minutes, it will lock up and display mostly white garbage on screen. I have to power down for 20-30 seconds before I can power up and start playing again, only to have the issue reoccur. I went through the diagnostics tests, and it seems to lock up when cycling through the Color RAM tests when it gets to white. I'll probably start a new thread for this issue....

@DogP , thank you again for finding the U120 fix!!!
 
hang on... U120 doesnt need to be pre-programmed before installation? LOL

BITD when I was operating these games I could get a replacement from our local distributor but they made it seem like it needed to be programmed. I thin they were charging us something in the range of $80 for the IC.

Geez.
 
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