Spy Hunter power problem

[whammoed]

depends on where that transistor gets its power. If it happened to powered from the +5 unregulated, then if that voltage dropped, it would drop the reset voltage as well.
I really think its a bad coin counter.

OK. That is quite a coincidence that the coin counter goes bad at the same time as the power supply though? We shall see. Anything is possible and I will check that.

Another thing I thought of is that the power supply is still just not regulating the +5 well and any sudden draw on the transformer causes a blip in the +5. (the unreg and reg +5 draw from the same place I think)

 

[whammoed]

Went to work on this today again. It is now apparent there is still a power issue. I could barely get the game to boot today as I could not turn up the +5 past 5.25. It did boot but after running a while I got garbage on the screen. I check the voltage and now can't adjust at all. It sits at 4.7.
I've got a different board coming to me soon and I will try it out when I get it.

 

[whammoed]

CRAP! Spy Hunter power problem

RATS!



Got a tested power board from TNT today. Same issue as with the rebuilt. I am unable to adjust the voltage past 4.3 with the boards plugged in. With the boards unplugged I am able to adjust the voltage fine.
Game still works fine with the switcher.
Could there be something wrong in the transformer assembly? Rectifier going bad? The large caps have been replaced already.

 

[whammoed]

Unplugged everything except three board stack.
Still same issue.
Tried different three board stack.
Still same issue.

 

[7146aaron]

SH

I have some test parts if you want to swing by some time and borrow them. Just let me know what you will need so I can have them ready.

 

[whammoed]

I have some test parts if you want to swing by some time and borrow them. Just let me know what you will need so I can have them ready.

You read my mind. I was just thinking of maybe asking you if you had a spare transformer assembly I could borrow to test. I'll be in touch if need be. Thank you for the offer.
Funny, I used to have a spare but sold it to a fellow klover...never thought I'd have a use for it.

 

[cdjump]

look at your harness, specifically the main .156 connector that connects the pcb to the harness - are the pins burned?
Also, if the 2 12 pin molexes that connect the power supply to the harness were corroded, chances are the pins on the harness are corroded as well. You may need to replace them.
You can take a voltmeter and measure at the power supply and the pcb, across the pins and see where your voltage drop is.
If you've tried 2 power supplies, and both do the same thing, chances are, you've got bad connectors in the harness somewhere.

And the coin counter could've been bad long before the power issues your having. They go bad. It does happen.

 

[whammoed]

Harness looks good.
Pins on board were never corroded. I replaced all connectors because I had replaced everything else and they came in the kit.
I'll check some more voltages tonight.

 

[kstillin]

Measure how much AC ripple voltage there is on your +5V supply.

You should really not have to crank this up to 5.25V to get it to run. Especially considering that it runs nicely off of 5V with the switching supply.

 

[whammoed]

Measure how much AC ripple voltage there is on your +5V supply.

You should really not have to crank this up to 5.25V to get it to run. Especially considering that it runs nicely off of 5V with the switching supply.

Can I do that with a multimeter set for AC?
If there is AC ripple would that point to the bridge rectifier?

 

[whammoed]

Got it going.
Was looking at the transformer and testing the diodes so I removed the fuses.
I figured while they are out might as well test them again. One of the 5amp fuses tested bad although it looked fine. So the power board was only getting half wave from the transformer which explains why I was able to adjust voltage without load but couldn't when the board was plugged in. Based on all the symptoms I suppose the fuse could have developed an intermittent connection since the rebuilt board did boot the game for a while and then stopped. Who knows?
Both the board from TNT and the rebuilt board work.
I get some static from the rebuilt board but I think that is from the new pot for the 12 volt. It is hard to turn. You get the same kind of static when you touch the metal on the pot of the other board.

 

[demogo]

Congrats on figuring it out.

 

[whammoed]

Congrats on figuring it out.

Thanks! Ran a 6 hour burn in tonight with no problems. Hopefully that's it for now.