Kung Fu Master

[Huffyuk]

Hi, I have just got my hands on a Kung Fu Master PCB. I'm using a PCBjunkie IREM adapter and a Supergun and just getting a second of colour blocks then a Grey Screen with what looks like a line rolling up each side. I removed and re-seated the chips and just the same so far.

Any ideas on what to check first for someone with limited skills. ha!
Cheers!

 

[r-type]

How are your voltages?

 

[sukhbir]

Is it original?
Was this purchased untested?
If its coloured blocks possible bad sprite roms or worst case scenario custom graphic chips,the top board handles the tile graphics and sprites.

 

[Huffyuk]

Is it original?
Was this purchased untested?
If its coloured blocks possible bad sprite roms or worst case scenario custom graphic chips,the top board handles the tile graphics and sprites.

Hi, thank you.
yes it’s original and purchased untested. It was cheap enough for a punt. thought I might have got lucky. One other thing I thought about is I use an old pc power supply. Would I be better getitimg a specific psi for these types of boards. Could power supply voltage play a part in the grey screen?

 

[sukhbir]

Using an old pc power supply is ok and should not cause any issues unless the game board uses -5 volts for the sound.
I suspect your game board is faulty,take a look at my repair log of kung fu master.

 

[Huffyuk]

How are your voltages?

I haven't tested them. What's the best way to test a voltage. I have a Multimeter with the two prongs. Do I put them somewhere on the board? Sorry I'm very new to this. The power supply I use is a 500w PC and the output it says is +5v.

 

[Huffyuk]

Using an old pc power supply is ok and should not cause any issues unless the game board uses -5 volts for the sound.
I suspect your game board is faulty,take a look at my repair log of kung fu master.

I'll have a look at your repair log, thank you

 

[bones]

It's best to test the 5v on the pcb, just pick a 74ls chip, if it's a 2 boardset that's linked by ribbon cable check a 74ls chip on the board without the edge connector, those ribbon cables cause allsorts of issues when they are old. Also with pc PSUs I used to cut the plugs off and bundle all the +5v cables together and the 0v cables together as a single cable may not be up to the job as these old ttl boards can draw much power. When I made my own looms I used to make sure there were 4 × 24/0.2mm for the 5v and at least that for the 0v line as well. I'd seen how quickly early fruit machines PSUs burnt these 2 voltage lines out lol maygay,bellfruit,barcrest all bad, seemed only jpm after the system 80 and mps1&2 got the psu and wiring right, even the more modern astras,project coin PSUs were underrated in my opinion.

 

[Georgian2]

It's best to test the 5v on the pcb, just pick a 74ls chip, if it's a 2 boardset that's linked by ribbon cable check a 74ls chip on the board without the edge connector, those ribbon cables cause allsorts of issues when they are old. Also with pc PSUs I used to cut the plugs off and bundle all the +5v cables together and the 0v cables together as a single cable may not be up to the job as these old ttl boards can draw much power. When I made my own looms I used to make sure there were 4 × 24/0.2mm for the 5v and at least that for the 0v line as well. I'd seen how quickly early fruit machines PSUs burnt these 2 voltage lines out lol maygay,bellfruit,barcrest all bad, seemed only jpm after the system 80 and mps1&2 got the psu and wiring right, even the more modern astras,project coin PSUs were underrated in my opinion.

I always remove all original gables and add my own thicker ones. Also I put an pot for 5V just in case. This PSU is easy to mod and has the -5V and -12V already.