MOTU 828MK2 USB not detected by Win7 (neither Mac OS)

[scipione205]

Hi,

I'm posting here because I have Win7, even if the owner of the 828Mk2 uses Mac OS, but I am in charge for repair his unit.

He gave me this 828 MkII USB, telling me that sometimes it does strange digital distortion on the master, not knowing why.
Also, the USB connector was soldered with wires and not directly on the PCB.

First I removed the wires and replaced a PCB-mouned USB connector; I checked the solderings and it was perfect; I checked with the tester if there was short-circuits and if very pin was connected with the appropriate PCB route, and everything was fine.

Prior to re-assembly, I noticed that the AC plug connector's solderings were cold and broken, so I repaired it.

Now the unit boots, but neither Win 7 nor Mac OS recognize it.

I tried to factory-reset, but nothing.

Now I will try the "burnishing the connectors" tip, right now.

If it will be useless, I would like to know if someone of you guys knows how to fix that, or if there's a service manual or troubleshooting procedures (as I always use when repairing electronicsequipments) or something.

Thank you very much.

[4stripes]

Sounds like someone was in there and wasn't very careful or thorough with what they were doing. Who knows what else might be broken. Troubleshooting a device like this at the component level may require an oscilloscope and skills that most people do not have. Chances are it is better to just get a replacement, or see if MOTU can send you exchange boards. At this price point though, that's generally not cost effective.

[scipione205]

I don't yhink that who soldered the USB plug using wires could caused something (even toygh the copper was ruined and the vias were completely destroyed), because the owner used the equipment after this 'repair' until now.

And, I am a professional electronic technician, I did professional service on professional electronic equipments for years, and I am able to use lab bequipment... xD