[Fatar] [Studio 900] – [No Power]
Good day!
Is there a repair tech among us who could point me toward common main board parts failures for the Studio 900 main board? I rescued one from being tossed. I’m using a generic 500 mA 9vDC adapter, center positive per the printed diagram on the machine.
I am about to hook up the oscilliscope, would like to know where to start.
Thanks for your time!
Color me embarrassed!
When I got the board to the lab, it only took 10 seconds under the microscope to find the burned 7805. Replaced the part, am going to put the controller back together and give it a test.
If you come across this, thanks for looking!
7805’s don’t just burn out, there is a capacitor that is turning into a resistor causing excessive current draw. keep looking
You are absolutely correct… the unit still doesn’t work… hoping to tear into it again over the weekend.
Thanks for your time!
That’s what I was thinking, but this thread is marked as closed!
Check the output of the 7805 (the 5v rail) and make sure it isn’t shorted to ground.
Yeah, I know I closed it, but I just found how to ‘reopen’ it. I haven’t had a chance to pop it on the scope yet… work has been crazy.
Use an ESR meter to test capacitors on the main board. You can buy SMD capacitors on Amazon.
Be careful resoldering and check carefully for any stray bits of solder on the board surface that can short. Also clean the board of dielectric leak from the old fried caps.
Thanks for the advice… I have a bunch of SMD experience, and actually was a trainer for it at one point… being able to work on surface-mount stuff has been an asset in my maker hobby!
I’ll keep you posted. Looks like I should be able to find time to get into the lab soon.