No 5v WPC

[robm]

Well the problem all along i reckon was the header pin of J101 - replaced these and it worked fine.  I reckon i was getting some of the AC readings as when i put one of the leads on pin 1 (which was tarnished) it might have just put enough pressure on it to get a reading - yet when i do a DC reading, there is no pressure on the AC input pins....dunno - just my thoughts.

Interestingly, the voltage is only 4.88 - even after jumpering everything and replacing all bridges and caps. From what i understand, the voltage regulators have a fairly wide range of operating specs, which is why i've tended to put a 22ohm resistor between the voltage regulator and GND to bump the output up a bit (normally to around 5.03v).  I'll leave this one as is for a while and see if there are any reset problems (which i suspect there will be with only 4.88)

Thanks heaps for the help

Rob

[beaky]

is that +4.88 volts loaded or unloaded (with the cpu and other things connect or not)
well done on finding the fault. by the way.

[Strangeways]

is that +4.88 volts loaded or unloaded (with the cpu and other things connect or not)
well done on finding the fault. by the way.

+1

Great result, Rob !

[robm]

is that +4.88 volts loaded or unloaded (with the cpu and other things connect or not)
well done on finding the fault. by the way.

Both from memory - i tried 1st with just J101 connected and i think it was still 4.88, then with everything connected its definitely 4.88

[beaky]

4.88 is a bit low. I just checked in clays guide and this is what is said. "+5 volts DC: TP2 (TP101 on WPC95). Should be 4.92 to 5.1 volts DC. If this is below 4.92 volts, the game will most certainly reset easily, as this is the voltage the "reset watchdog" examines."
There is more on this in the guide but i didn't copy it on here, I don't want this forum to get into any pooh over copyright issues.
I hope i am allowed to post that part of the guide here.

[Strangeways]

4.88 is a bit low. I just checked in clays guide and this is what is said. "+5 volts DC: TP2 (TP101 on WPC95). Should be 4.92 to 5.1 volts DC. If this is below 4.92 volts, the game will most certainly reset easily, as this is the voltage the "reset watchdog" examines."
There is more on this in the guide but i didn't copy it on here, I don't want this forum to get into any pooh over copyright issues.
I hope i am allowed to post that part of the guide here.

Its no problem, Andrew - as long as you quote the section and credit the author. Even a link to the section will suffice.