Monstermug
Active member
Got a Hyper Sports reported to have graphics glitches that would go away when some chips were pressed on.
Received it and there was no sound coming, just a small hum. Volume pot did nothing to change the volume of this hum. Used audio probe on output pin 7 of LA4660 amp and got no output. Probe Pin 2 and got input. Replaced amp and sound came back.
Graphics glitch was that character sprites were corrupted. This was mostly noticeable but not limited to, the long jump, archery and javelin. There was no effect on weight lifting or swimming events.
Mame source states that graphics roms were C14 - C22. Verifying roms found rom at J19 to be bad. I worked out that this was C14 by reading the working roms and using Romindent.
Burnt new rom for C14 on 2764 chip and got partial sprites back but still had corruption. This time there were purplish boarders around character sprites.
Then realised that Konami compressed C13 + C14 onto a single mask rom at location J19. This was equivalent to a 27128.
I didn't have any 27128 in stock so I used a 27256 and the above commands to compressed the files and burn it twice. I did have to play around with the order of the files but eventually got it right.
Put newly burnt 27256 back on the board and got all graphics back as normal.
With no corruption on any events at all!
Whist celebrating my victory, I noticed the sound started to go all weird before disappearing altogether after a reset.
Firstly I thought the amp had died again but probing input pin 2 and op amps with an audio probe I got no sound there either.
Checked clock on CPU z80 and address lines and they seem to be working fine. Checked sound addressing circuitry and BM4K reported those chips to be fine. Didn't know how to check the 40 pin custom sound chip but I believe this only deals with the voice sounds.
Attention turned to a mystery chip near the Z80. This seemed to be connected to the sound circuitry.
I pulled it and put it in the BM4K to identify what chip it was. It reported not found. It doesn't find faulty chips anyway.
Looked at some pictures online and found another revision of Hyper Sports.
This one had two 2114 ram chips (1K x 4Bits) in place of the mystery chip. I then deduced that the mystery chip must be a 2K 8bit ram.
Plopped it back in the BM4K and tested it as a 2016 ram and got stuck I/o on pins 15/16/17 which reduced to only Pins 17 after a fail loop test. Couldn't fix pin 17 so I looked around for some ram.
I had a TMS2016 ram in stock and socketed this on and got sound back.
With no other faults this is now done and dusted.
Received it and there was no sound coming, just a small hum. Volume pot did nothing to change the volume of this hum. Used audio probe on output pin 7 of LA4660 amp and got no output. Probe Pin 2 and got input. Replaced amp and sound came back.
Graphics glitch was that character sprites were corrupted. This was mostly noticeable but not limited to, the long jump, archery and javelin. There was no effect on weight lifting or swimming events.
Mame source states that graphics roms were C14 - C22. Verifying roms found rom at J19 to be bad. I worked out that this was C14 by reading the working roms and using Romindent.
Burnt new rom for C14 on 2764 chip and got partial sprites back but still had corruption. This time there were purplish boarders around character sprites.
Then realised that Konami compressed C13 + C14 onto a single mask rom at location J19. This was equivalent to a 27128.
I didn't have any 27128 in stock so I used a 27256 and the above commands to compressed the files and burn it twice. I did have to play around with the order of the files but eventually got it right.
Put newly burnt 27256 back on the board and got all graphics back as normal.
With no corruption on any events at all!
Whist celebrating my victory, I noticed the sound started to go all weird before disappearing altogether after a reset.
Firstly I thought the amp had died again but probing input pin 2 and op amps with an audio probe I got no sound there either.
Checked clock on CPU z80 and address lines and they seem to be working fine. Checked sound addressing circuitry and BM4K reported those chips to be fine. Didn't know how to check the 40 pin custom sound chip but I believe this only deals with the voice sounds.
Attention turned to a mystery chip near the Z80. This seemed to be connected to the sound circuitry.
I pulled it and put it in the BM4K to identify what chip it was. It reported not found. It doesn't find faulty chips anyway.
Looked at some pictures online and found another revision of Hyper Sports.
This one had two 2114 ram chips (1K x 4Bits) in place of the mystery chip. I then deduced that the mystery chip must be a 2K 8bit ram.
Plopped it back in the BM4K and tested it as a 2016 ram and got stuck I/o on pins 15/16/17 which reduced to only Pins 17 after a fail loop test. Couldn't fix pin 17 so I looked around for some ram.
I had a TMS2016 ram in stock and socketed this on and got sound back.
With no other faults this is now done and dusted.
