If the screen noise is solely from the M4 then removing it with an RF case and feed-throughs should fix the problem but there are NO guarantees and it can be expensive. IMHO the monitor should not be affected in this way to start with but a lot are and that doesn't excuse the fact they should be rejecting this noise.
The post on MIC and Line input noise was a general bit of info for anyone having PSU/digital noise on their MB inputs. You can get this noise even with an AC (mains) supply with certain USB powered sound sources and that cure almost always works.
Sorry I can't be of more help.
I've been alerted to this thread by the MonkeyBoard makers...... I've got said radio and since installing the PC in the car with my M3-ATX, I've got no signal on DAB or FM :( Looks like it's a common issue!
So, accepting there seems to be a lot of issues with the Mx series of intelligent PSUs, realistically, what are the remedial options? The interference free PSU box is (probably) past my capabilities, but not only that, there's next to no room in my car to fit anything else outside the M350 PC case. The whole build was based around the MonkeyBoard radio & GPS capabilities, so I really need to get this up & running.
Is there hope for a fix or is it time to look for a new PSU? Any if so, what's the best alternative to replicate the M3's functionality which isn't going to kill the rest of the system with interference?
It looks like there's some very clever minds pondering this, so I hope there's some hope out there!! Cheers :)
Personally, my thinking is that, outside of building the special enclosure, you can use a regular ATX supply with an inverter and an intelligent power switch. Those seem to be pretty "quiet"
Your problem is size. There were low noise supplies available last time I searched but are quite expensive and did not have all of the delayed on/off shutdown features. If the DAB-FM board is mounted inside the case then make sure the coax shield on the aerial lead is also grounded where it enters the case and also from the aerial socket on the DAB BOARD to case ground. Each install causes varying degrees of interference so it's not easy to solve/reduce some interference problems in a forum. The obvious things like a very short 4G cable from PC case to vehicle chassis and keeping the aerial as far from the PC as possible are the first things to try (if you haven't already). Interference is also carried along vehicle wiring and therefore the layout and placement of wiring looms for a certain model and make of vehicle also affects interference.
As far as interference goes - one tiny SMPS inside a CMOS reversing camera was enough to totally kill DAB-FM reception, had to try 4 different cameras until I fond one that didn't do that.
From scanning this thread, I think you're absolutely right Mickz - no 2 installations are the same, neither are the issues / fixes!
The frustrating thing is the intelligence of the PSU the backbone of the PC, without a proper PSU the whole thing falls apart. However, if the PSU is killing the key functions of the PC, it's also a pointless installation! Catch 22 :(
Mickz, as I'm no electrical engineer, I'd appreciate some practical advice on how to go about better shielding the aerial and then the best way to ground everything, to give the install the best chance of success. Would it be OK to take this off-line and reach out to you directly?
No problems, always happy to help where I can. It would help if I knew the placement of the MB, DAB module and interconnecting wiring along with aerial location and battery and chassis/ground connections.
Originally Posted by 356Speedster
EDIT In the meantime if you can, try plugging the DAB module into a Laptop (long USB cable) and running in its current location with and without the car PC fired up and note exactly when reception stops during the car PC boot cycle.
Hello to all forum writers ... I have a question to ask, specifically, I have a problem with a TV antenna to the interior. By testing the antenna with a field meter I found that the PC receives the channel normally off, as soon as I turn on the PC does not receive anything. In your opinion where is the problem? The M4 ATX power supply? or a PC? I tried to shield the houses but nothing has changed. We accept suggestions and advice.
Someone who uses the TV on car-pc, that solution adopted?
I put the power supply in metal box from the feedthrough capacitors 1n but the antenna still does not receive anything. money down the drain. : (
Did you try a DIFFERENT supply with the PC?
If the TV worked the problem is the M4, if the TV didn't work then the problem is the PC.
When you test different equipment, everything must be placed in the same location under the same conditions, otherwise the test is invalid.
If you proved that the M4 caused the problem, what material did you use for the case?
Can you post a picture of the M4 in the shielded case?
hello. I am afraid that the problem is in the common gnd and that the pc in the car, the chassis of the car behaves as a large antenna. I did a test powering the PC (by car) with a 220v atx to the problem disappears. then I said to myself. M4 will be the problem. I connected the PC is not only M4 I fqtto leave without PC. et voila problems not to be. then I came to a conclusion that everything is generated between: auto/m4/pc now and figure out how to solve it. for more photos later I do. hello mickz