HANG ON repair log

[parism]

I don't post repair logs but since there are not many for Hang On, I decided to post this.

I got this a few months ago as complete but playing blind in the cabinet. Upon hooking it up on the bench the game was running, sprites were good, audio and controls were fine. All RAM passed. But, the road was messed up.

Disconnecting the small pcb stack made the sprites disappear but the issues remained.

I concluded that the problem was on the large pcb stack and thus much easier to troubleshoot (these pcbs are HUGE!).

Based on the schematics

http://www.jammarcade.net/files/Schematics/Arcade/Hang On.pdf

it seemed that the sub CPU (circled below) was likely involved in the road rendering.

Being familiar with the road circuitry in OutRun, I focused on page 11 of the schematics.

The pcb was riddled with Fujitsu TTLs, a very bad sign. I started probing around the sub CPU and the LS157 at IC76 (7P) had several stuck pins. I used the BUGTrap and immediately found errors

Piggybacking with a known good LS157 fixed the road problem. Naturally the IC from the PCB failed out of circuit

Replacing together with a socket fixed the road

Reconnecting the small board brought back the sprites.

Retested for video, audio and controls, all ok.

That was an easy repair for an awesome racer. I hope someone finds it useful.

Paris

 

[Charles Kline]

I don't post repair logs but since there are not many for Hang On, I decided to post this.

Thank you for posting it, I love reading repair logs and Hang On is a cool game. I have memories of playing Hang On at a campsite we would go to when I was a kid.

The pcb was riddled with Fujitsu TTLs, a very bad sign.

Do Fujitsu TTLs have a high failure rate?

I used the BUGTrap and immediately found errors

Please tell me more about this bugtrap, is it just light piggybacking a chip but you can turn each leg on or off to find out what is stuck? Looks like something that could be kit built...



Thanks,
-Charles

 

[Spunky_Bruiser]

Oh man, I have, or will have a hang on in sad shape but complete. I will need to rebuild the whole base from water damage kind of thing. Thank you so much though you kind of gave a few ideas to start with mine. I have other issues with my pcb and it is really weird. The game starts it would seem but no bike on screen, no other bikers racing but the course drives, and moves. when I get it home I will see if it even times out. I took a video of it, it is wild. I picked up another pcb already to swap roms out to narrow down my search. I am very glad you posed this. I might have a problem with my small board and might look at the connections or start there. Thanks again!!!

 

[BadDudesBruh]

Where was this 5 years ago, I had to get rid of mine because I swear it was jinxed and I couldn't find any logs any where LOL.

 

[parism]

Thanks, my apologies, I did not explain the piggybacking well. It just involves putting a known good IC on top of the suspect one. It does not always work, but if it does and the issues go away, it's a good indication the suspect IC is not working correctly.

Yes, Fujitsu TTL are known for their failures. A Pinball Action I repaired years ago had 20+ of them bad.

As for the Bugtrap, it is the white device with the colored ribbon cable in the pics. It's a logic comparator similar to the HP one (which is more common) but can also do 20pin devices. I believe someone here in KLOV made a repro a few years ago. The manual for mine is here:

http://gamearchive.askey.org/General/Test_Equipment/Ecomms/TTLBugtrap.pdf

Some brief info here

http://lawnmowerman.rotheblog.com/bugtrap.html

They are hard to find. Of course, it is not a magic wand for pcb repairs, just another tool.

Paris