‘Rod_Wod’ sent in dump of the unique PAL from a FixEight PCB.Original device was an unsecured PALCE16V8H, dump has been successfully tested by him onto a same device and a GAL16V8 too.Thanks again to him.
A quick repair for this Sky Kid (Namco) I received some days ago :
Board was in near mint condition but it didn’t boot sitting on a semi-static garbage screen (which was looping sign that watchdog was active)
Most of the devices were socketed so for first I ruled out the many custom ICs present, they were all working.Then I tested the RAMs out of circuit.Two Mitsubishi M58725P (2k x 8-bit static RAM) failed (at different address location)
Replaced them with compatible 6116 and board successfully booted with no further issue.Job done.
We have some new dumps from an unusual arcade hardware called High Rate DVD, a DVD-based mahjong system released by Nichibutsu in different volumes, you can read more about here:
256KB binary dumps have been provided by ‘system11’ on Dumping Union list, I took care of reversing them to GAL16V8 targeting devices.Each PAL (identified by a colored stripe or dot on chip) is shared among more than a volume and other Mahjong games too, you will find info on database.Thanks to ‘system11 who also successfully tested dumps back on hardware.
New PAL dumps today.We have the ones from :
Received some Irem 92 boardsets mostly for replacing preventively the infamous ELNA brown electrolytic capacitors but two of them were faulty too.
The first was a Cross Blades (japanese version of Blade Master!), board had green ELNA capacitors so no strict need to replace them.
But it suffered from sprites isssue, they were missing some parts:
Pressing the board in the area of ‘NANAO GA22’ custom ASIC restored the sprites :
A closer inspection of this custom revealed three liften pins :
Reflowed them fixed the issue :
The second board was Hook (World version) :
Game booted up but sound was missing, I could hear only a rustling noise.Besides, video had some interferences:
Usually the two issues are strictly related, the cause is some bad electrolytic capacitor in audio circuit which affects video output too.The board mounted ELNA brown capacitors which are well known to age poorly.Sure enough :
The 470uF 25V @C202 was clearly leaking, this capacitor is used as filter for the +12V for the amplifier, this explained the issue.Measuring it out of circuit confirmed it was bad with an increased ESR of 150 Ohm :
I replaced this and all other electrolytic capacitors, this fixed board completely:
Here’s for reference the capacitors list with value and location :
C201 1uF 50V
C202 470 uF 25V
C203 220uF 10V
C204 22uF 25V
C209 100uF 25V
C210 1uF 50V
C213 47uF 16V
C215 1uF 50V
C216 1uF 50V
C217 1uF 50V
C218 1uF 50V
C219 1uF 50V
C236 100uF 25V
You can find it in our document section too :
https://www.jammarcade.net/files/Documents/Irem_’M92-A-B’_CPU_board_electrolytic_capacitors_list.pdf