Lasonic i931x issues

[blu_fuz]

I purchased this box as "non working" because it didn't power up.


When the box arrived I plugged it in and flipped the switch to AC on the back and it was working 100%.



Unplugged it, put it back in the shipping box.



Took it out again 2 days later, plugged it in and was still working 100%.



Put it on the shelf. Plugged it in 2 weeks later and now it's dead . Not working on AC or batteries .



I opened it up to see if there was just a loose connection or something obvious, but I couldn't see anything wrong. Fuse under the power circuit board looks to be in OK shape too.... So, I need help. What to test, where to look, any ideas are appreciated.


Thank you!

 

[k2j]

I think the Fuse is for the AC circuit only, but you could do a continuity check on that to verify that the fuse is not blown (visual inspection doesn't always work). Make sure you check continuity with the box unplugged from wall and batteries out of the boombox!!!\

Also, is it just simply the power switch is gummed up and working intermittantly? Try flicking the switch on off a bunch of times fast, then try slowly and listen for crackling.

hmm

 

[blu_fuz]

I will try to check the continuity of the fuse.


I also did try moving the ac/dc switch around and sprayed with deox for good measure, still nothing. No crackling, no buzzing, nothing .


I checked every wire connection too, because that makes the most sense to me that a connector isn't engaging. But they all seem OK and tight .



I might take the rear case off my i931 and plug it into the front side of the i931x to see if it is just a power issue. If it still doesn't work with that, then I have to suspect something is bad on the the front parts....

 

[skippy1969]

Now that sucks........... :annoyed:

 

[blu_fuz]

Ok, a little progress here....


1. rear case of my black i931 and hooked it to the front side of the white i931x = dead
2. rear case of my white i931x and hooked it to the front side of the black i931 = works


So the problem lies on the front circuitry of the white i931x....


Now what? I see nothing burned up, exploded, loose, or damaged - it's simply just dead. How do I find where the issue is with circuit boards that have such SMALL solder spots that I can barely destinquish them from eachother

 

[baddboybill]

Joe I would start by testing for power at power switch make sure you have input power to switch then output power. These power switches use same type control module like the one Norm produced for the M70's That could be defective part

 

[blu_fuz]

That should be easy to test - how do I do that?


Seriously, I have a meter but don't know how to use it.....

 

[baddboybill]

That should be easy to test - how do I do that?


Seriously, I have a meter but don't know how to use it.....

Set your meter to more than 15v dc test ...Find a good ground on box. Using black probe hold it to ground... With red probe test wires that come off power switch, I believe it's attached to small board.... I cant remember how many there are off top of my head...You have to test with box plugged in after testing all wires power up bbx power switch and then retest... Let me know if there is a difference in tests