Mpeg uSDC

**MatrixPC** · 12-05-2006, 10:18 AM

Jeff and everyone who use it,
I bought a uSDC from fellow member here. So far, this part of the connection get me confuse.
Do I have to put a diode on the "Computer on Sense" pin inline with 12V wire from a molex connector? Can I use other source such as 5V, 3.3V or it has to be 12V?
I just want to know that if a diode is a "must have" component cuz I don't want to fried the PSU (sproggy) and/or the uSDC.
Thanks guys.

**MatrixPC** · 12-06-2006, 10:19 AM

Dam, no one use this uSDC?
I guess I just have to wait for Jeff to answer.

**zootjeff** · 12-07-2006, 10:32 AM

Originally Posted by MatrixPC

Dam, no one use this uSDC?
I guess I just have to wait for Jeff to answer.

No you don't need the diode. You can connect this to a 5 volt connection on the motherboard, or connect it to a 12 volt source using the diode. If only using a 5 volt source, no diode needed..

**_dopehead_** · 12-07-2006, 11:32 AM

So one could actually just use the 5V off the molex 4-pin instead of the 12V and be rid of the diode "circuit" ?

**MatrixPC** · 12-07-2006, 01:25 PM

Thanks Jeff.
So for short.
If using 12V source, a diode is a must.
If using 5V source, no diode needed.
5V or 12V source can be from HD molex or 20/24 pins ATX connector.

**MatrixPC** · 12-12-2006, 06:38 PM

I think the uSDC is dead.
Connect everything up, but no relay clicking, no LED no VOUT, fuse is fine. I have no idea what going on.
Little about the setup.
I built the Sproggy PSU with the SDC and has been working fine for the pass 2+ years. The SDC part has problem as it isn't cut off the power to the PSU and it is in standby mode the whole time. That cause flat battery if I don't drive the car for a week. I modify the PSU to remove all components of the SDC. Now if I apply power to the PSU, it will be on standby. If plugin the mobo, the mobo will turn it on and everything will work. But I have to manually shutdown the PC and remove power to the PSU.

With the uSDC, Vout connect to the PSU Vin, and ground to ground. Mobo power SW is connect as normal. On-Sense is connect to 5V (part of the ATX connector) with a diode.

There is a 4GA wire run from the battery to a distro block that branch to the amp 8AG and the PC with 3ft run of 8GA wire and 2ft 8GA ground. Battery voltage is about 12.52V (according to my cheapo meter). Voltage accross the fuse is also 12.52V. I adjust P2 to the minimum. SoCal weather is 60F-70F so voltage and weather isn't a problem. I brought the uSDC inside and test with my spare battery, still no sight of life. All connectors are rock solid and no burn mark nor burn smell. Basically, it looks in perfect condition.

Search the forum and most of the problems related to the uSDC is continuous clicking relay and shudden shutdown. No one has problem like I did.

What is the problem with the uSDC and Any idea how to fix it?

**zootjeff** · 12-13-2006, 05:43 PM

Originally Posted by MatrixPC

I think the uSDC is dead.
Connect everything up, but no relay clicking, no LED no VOUT, fuse is fine. I have no idea what going on.
Little about the setup.
I built the Sproggy PSU with the SDC and has been working fine for the pass 2+ years. The SDC part has problem as it isn't cut off the power to the PSU and it is in standby mode the whole time. That cause flat battery if I don't drive the car for a week. I modify the PSU to remove all components of the SDC. Now if I apply power to the PSU, it will be on standby. If plugin the mobo, the mobo will turn it on and everything will work. But I have to manually shutdown the PC and remove power to the PSU.

With the uSDC, Vout connect to the PSU Vin, and ground to ground. Mobo power SW is connect as normal. On-Sense is connect to 5V (part of the ATX connector) with a diode.

There is a 4GA wire run from the battery to a distro block that branch to the amp 8AG and the PC with 3ft run of 8GA wire and 2ft 8GA ground. Battery voltage is about 12.52V (according to my cheapo meter). Voltage accross the fuse is also 12.52V. I adjust P2 to the minimum. SoCal weather is 60F-70F so voltage and weather isn't a problem. I brought the uSDC inside and test with my spare battery, still no sight of life. All connectors are rock solid and no burn mark nor burn smell. Basically, it looks in perfect condition.

Search the forum and most of the problems related to the uSDC is continuous clicking relay and shudden shutdown. No one has problem like I did.

What is the problem with the uSDC and Any idea how to fix it?

If it is not turning on, the P2 jumper could be set to high. Or somehow it got fried. Like I always do, you can send it back and I can fix or replace it..

Jeff