Re: 2445 LVPS Issues


tom jobe <tomjobe@...>
 

If you are talking about the black cover over the two largest capacitors, there is a prong that goes down in the middle between the two bumps, the prong has a hook on one side of it that latches the cover in place. You deflect the prong to the side a little bit and the cover comes off in your hand. Maybe wait until you have the power supply out on the bench before trying to remove the black cover?
Those two large capacitors never seem to give any trouble in a 24x5 but have a look anyway and check the ESR if it is easy for you to do. Replace all of the smaller caps regardless of how they look or the ESR checks out. I see you have been warned about the schematic errors on two of the capacitors, don't miss this problem.
There is excellent help available here on Tekscopes for the 24x5 scope family.

On 8/3/2019 4:13 PM, n4buq wrote:
I was using my 2445 today when I heard a strange sort of thump noise coming from inside the scope after which I startettd smelling a burning odor. I had a few pieces of gear powered up at the time but quickly could tell the smell was coming from the 2445.

I took off the case and top cover and pretty sure the smell is coming from the LVPS board(s) but am a bit stumped at how to get those two boards out. I'm pretty sure the top ribbon cable needs to come off but don't quite see how to get the large plastic cover off of the area where the main filter caps are.

Looking at some of the smaller caps, they appear to be leaning due to (I'm guessing) bulging at the circuit board end but not sure exactly what overheated (or, possibly, made that thumping noise).

Are there instructions somewhere that outline how to remove those boards? If not, could someone provide a couple of hints to get me started?

Thanks,
Barry - N4BUQ


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