Sega Hang On missing motorcycles & signs

[jeffklam]

I've got a Hang On machine that is missing the motorcycles and signs. It also displays the Hang On spinning logo as vertical lines. The road, backround, score, and other text are ok. Rom/Ram self test comes up good. I've tried swapping cables, CPU's, reseating all Eproms, etc. Does anyone have a manual or schematic that would show which eproms or circuits deal with the motorcycle graphics? Anyone got boards for this machine?

 

[Angry_Radish]

Sorry, not too much help here, but here are the schematics:
http://arcarc.xmission.com/PDF_Arcade_Manuals_and_Schematics/Hang%20On%20Schematics.pdf

I haven't looked at them too closely, but if all else fails try mame, you could try to reproduce it and possibly find out the culprit..

 

[jeffklam]

Thanks for the link. How do I mess with the Hang On roms? I have it running in Mame, but I don't see how to change roms.... Do I just alter the rom files somehow?

 

[metahugh]

You should be able to just open up the rom file in a text editor like notepad and add some characters or delete some data, save it (make a backup of your mame roms first

) and run the game. I just messed with 5e for the Ms pacman set and it warned me that there was something wrong with one of the roms, the game played but had bars running through everything.

This would be easier than reading the schematic because you could find out really quick which rom handles the characters and just replace that rom.

 

[metahugh]

Ok I think I just got extremely lucky. I modified the first two roms in the archive:

epr-6819
epr-6820.ic34

I removed all data in those roms and now I get a screen with no characters or signs anywhere. Do you get the dust on the ground appearing when you ride on the side of the road? I did see this effect.

Check out the screenshots from MAME:

Only EPR-6819 Damaged:

Both roms damaged:

 

[jeffklam]

Thanks for the mame info. I did the same thing on mine and found that the following are related to my problem.

6819 & 6820 Motorcycles missing
6821 & 6822 Trees missing
6825 & 6826 Starting lights and signs missing
6829 & 6830 Title missing
6827 & 6828 Crash graphics missing
6845 & 6846 Sega logo missing

This is approximately what my looks like. Now the question is.... what do all these have in common? Are they all on the same board? I'll have to check my boards and see if I can find these. I don't see anything on the schematic that lets me cross reference the 6820 with IC 34... Is this info in the manual?

 

[D_Zoot]

I can't tell you what's wrong with your Hang-on, and I hate to be a stick in the mud, but:

The motorcycle graphics are generated seperatly from the background and text/score display on this board, anything that kills this section of the board will give you this symptom, this includes all the supporting logic. The logic used on the board (Toshiba if I recall) was sketchy at best and a bad logic IC somewhere wouldn't surprise me. These boards can be a real PIA to troubleshoot.

The ROM problem idea is possible, though probably not the issue. But I thought I'd give you a heads up in case that doesn't lead anywhere.


Cheers,
D

 

[jeffklam]

I can't tell you what's wrong with your Hang-on, and I hate to be a stick in the mud, but:

The motorcycle graphics are generated seperatly from the background and text/score display on this board, anything that kills this section of the board will give you this symptom, this includes all the supporting logic. The logic used on the board (Toshiba if I recall) was sketchy at best and a bad logic IC somewhere wouldn't surprise me. These boards can be a real PIA to troubleshoot.

The ROM problem idea is possible, though probably not the issue. But I thought I'd give you a heads up in case that doesn't lead anywhere.


Cheers,
D

I've figured out that basically all of the eproms that are associated with the missing graphics seem to be on one board. It's the rear board of the lower two smaller boards. It looks like one of the two electrolytic caps has been replaced at some point. Could one bad eprom on this board affect the others? The voltage to this board is ok and I tried swapping power connectors with the one in front to double check. No change. What I really need is a spare set of boards to at least narrow it down to one board.

 

[tta583]

I've figured out that basically all of the eproms that are associated with the missing graphics seem to be on one board. It's the rear board of the lower two smaller boards.

First off I have never seen this board set. Second, I am DEFINITLY an idiot when it comes to electronics.

Given that.....

Is this what the board set looks like?

You say they are all on one board. The rear board of the lower 2 smaller? I am guessing the set is mounted with the small boards below the larger and that there are 2 small boards stacked. You problems are looking to be on the 2nd smaller board?? Anyway You said you swapped power. Is there a separate power pigtail for the individual boards. There is some wire coiled up in that pic. Are the ribbon cables the same pin counts? Swap a couple to see if the problem moves. Look at the cable receptacle to see if they may be damaged or have a bad solder joint. Beyond that I would figure out how to separate and suspend the top board so that you can run the game and have access to the lower board. Then start looking at the address lines for those EPROMS. You need a logic probe to do this correctly. My guess is they are all on a common bus. As the game runs you should see them pulse. If they check out start looking at the data lines. They should be pulsing as well. If you have a problem on either side you should be able to easily trace the lines back (address pins) our forward (data) to the bits of logic in those circuits.

 

[tta583]

Just thought, check power to the eproms? Like at their power pins. Check the ground as well. Look carefully for a broken trace or component that may have cut off the power or ground rail.

 

[jeffklam]

That is the correct board set as far as I can tell. These double stacked boards aren't fun to work with. Thanks for the info. I'll see what I can come up with. I haven't used a logic probe for about 17 years.

 

[jeffklam]

The +5V and Gnd are good to the chips on that board.....