Work in Progress: Hyper Sports

channelmanic

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Donor 3 years: 2011-2013
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Apr 5, 2008
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OK,

This is a board from hell. Not sure what happened to it but it HAD to be a power surge of some kind.

Symtpom: Graphics corruption. Foreground AND background.

EPROM C26 was bad. Replaced.
Signals on the address lines of C11 to C18 were incorrect. Replaced F15 and F16

Working backwards from the outputs I found:
Output pins stuck on MOST LS157 ICs. Replaced C17, D17, E17, D16, and A4
Output pins stuck on D11, E11, E12, G12, E13, F13, G13, and F14.
Pins racing on D9, E9, E10, H10, and J10.

All of those chips tested bad on my EPROM programmer. EEEK.

Now I have graphics but have some sparklies around border graphics and a missing title screen to track down. It appears that C20 and C24's OE* lines are not going active. I already replaced the LS139 at D11 and the LS273 at D9. This last bit is frustrating.

RJ
 
Fixed!

Bad 74LS04 on the CPU board and LS377 at H12 on the video board.

Whew. This thing has been a beeyatch from hell.

I picked up a dead Hyper Olympics 84 board from a forum member (Listed as Hyper Sports) and it's running but with corrupt player graphics. I used the CPU board from it to track down the problems on the Hyper Sports video board.

So far I replaced the 504 and the 082 chip with ones from a donor Track & Field board.
 
TIP:

If you can't find a 504 chip, there is a daughter board that can be used in place of it. It's labeled: PWB 4000206A
 
Well,

This Hyper Olympics board is kicking my ass... The player graphics are all over the place scrambled across the screen. Everything else is perfect.

Signal DM7 (pin 11 of H3) is stuck low. The chip at H3 and the chips it drives at J4 and H4 are all good. Looks like the CLK4 signal is incorrect. A check of the good board shows pulses in groups of 3 and the bad board shows pulses in groups of 2... I'm pulling my hair out.

OH1, 2, 4, and 8 are good signals. Looks like that leaves E14, F16, F18, and E16.

Am I overlooking anything? I'll swap those chips out tomorrow night. Right now it's bedtime.

Sigh...
 
I have a board that I believe to be working if your interested.

Thanks, but I'm pissed off at this board and will keep working on it until I figure out what's wrong with it.

Once it's fixed, I'll be selling both boardsets. Right now I'm keeping the working set to compare signals to the broken board.
 
FIXED!

Bad 74LS20 at location E16

All the inputs looked good. Output was missing a single pulse which was causing the CLK4 signal to be wrong. This caused the counter at H3 to have an output that was low on pin 11 which cascaded through and caused the player graphics to be corrupt.

WHAT A PITA...
 
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