Got the HAPP power supply in, and it too showed low voltage... after some checking, it looks like the coin slot bulbs are causing the voltage to drop. Which seems, not gud. Disconnected them and I'm getting close to 12v with the HAPP and just over 10v from the original PSU. However with the HAPP, even with the potentiometer cranked all the way down I'm getting close to 6v on the 5v pins. So I think that if I had the original at a similar setting (it's setup almost dead on at 5v) the 12v line would be more or less the same.
- Thread starter Kujako
- Start date
You cannot measure voltage from a psu without load !
For my mvs, what i did is measuring the voltage at the VCC and GND directly at the 68k pins. When i had flat 5.0V, i was getting 5.15V at the jamma edge and 5.25V at the PSU .
Without load, i have 5.3V at the PSU.
i suggest you turn all the way down the voltage setting pot and measure voltage on the board powered to see what you really get !
for your 12V, maybe you have that drop because the psu cannot sustain the draw ? Too much amp.
For my mvs, what i did is measuring the voltage at the VCC and GND directly at the 68k pins. When i had flat 5.0V, i was getting 5.15V at the jamma edge and 5.25V at the PSU .
Without load, i have 5.3V at the PSU.
i suggest you turn all the way down the voltage setting pot and measure voltage on the board powered to see what you really get !
for your 12V, maybe you have that drop because the psu cannot sustain the draw ? Too much amp.
So I have two PSUs at this point. The original Peter Chou and a cheap HAPP. I would think I would see the voltage drop under load, so given the measurements I have the HAPP would be the safest, but I worry about it being so far above 5v. On the other hand, 12v is mostly used for audio so the Peter Chou PSU would be safer, but it's at around 10v on the 12v pin. Still, if I'm not having audio issues it may be working just fine...
And a quick test later, the original PSU under load is showing correct voltages... so I'm just an idiot who forgot basic electronics. Hooray!
Now I guess I'm out of excuses to do a full CRT retuning (it's orangeish).Hooray !.
no excuses hahaha