We know this Russian customer from late May, we overcome many problems, such as components replacement, shipping to Russia, sign NDA file...Finally, we have successfully cooperated. He release these 2 projects of computer and audio PCB board. One is Main board 50pcs , another is audio driver PCB 150pcs. Now we are on prototype step, after testing, we will start larger quantity.

The main board is a 4 layer PCB,TG130,1.6mm board thickness,1/0.5/0.5/1oz copper thickness, surface finishing HASL,solder mask is green,silk print is white. Fabricate per IPC-6012 Class 2, punch tooling hole registration tolerance +/-0.005, conductor width tolerance +/-20%, UL approved, the board size is 154mm*125.65mm. We make it into panel, panel size is 168mm*251.3mm/2pcs,V-cut. We do assembly work at our factory, so we could accept X-outs board, it could save the cost of PCB making.

The audio driver PCB is a 2 layer PCB, TG 130-140, 1.0mm board thickness, cooper thickness is 1oz, surface finishing is HASL, solder mask green, silk print white.

After first quoting, the customer do a little adjust for BOM list. He delete C1 and C2,HL2,HL4,FBA, plus a 2 pin connector. The customer accept replacement component, but about connector, we must carefully check all specification, as the PCB board will connect to the connector in customer device, it must be 100% meet the requirement. The customer also emphasized that the relay must be consistent with the BOM parameters, otherwise it cannot be connected with the customer's equipment. Normally, the accuracy of the resistor has 5% and 1%. The higher the precision is, the higher the accuracy of the device have. Customer requires 1% precision resistors, so we change all resistors into 1% accuracy, the totally cost will change a litter higher, but we firstly want to meet our customer requirement.

The main PCB board has more than 25 kinds components with single side mounting, the audio driver PCB board has more than 14 kinds components with two sides mounting. 

After assembly work, we should do a key step that is to test the PCBA. The test process is as follows:

Linux with installed ALSA with supported usb audio and USB 2.0 port. It’s a uncommon system in China, we always use windows system, so we must change the system of one computer in our company to do this test. USB wires must be connected as pointed on the image below:

VCC/GND must be connected via top-left connector (in accordance to pcb labels  +5V /GND)Data plus and Data minus must be connected to pins at the bottom-right identified as DP and DM correspondingly.

After USB connection, you must see PL-G1 green led constantly activated for 6-9 minutes (ON STATE period). In this state should be able to see Terminus 2.1  hub available on the usb devices list like: 

Voltage probe (V/Probe) must show around +5V. After ON-STATE period around 6-9 minutes we should see PL-G1 off and PL-R1 red led activated (OFFSTATE state) as well as you should hear relay switching sound.

During the test, our customer told us may see some EMI errors when CM118B / MAINBOARD is connected/disconnected, but these errors should not make the devices malfunctioning. For instance after any EMI error the devices must reconnect and return to normal state automatically.

About audio driver PCB, Once it is connected we should be able to see this audio card in lsusb output as C-Media device. As well “arecord -l” command should show new audio device in the output.

We will inform the customer 8-10 days earlier before shipping the goods. We will first use anti-static foam to package, then we put them in carton. This is first time cooperation, will be a good beginning between us.