Sencore LC53 leakage test acting up?

[Shakedown St.]

Hi there EP Forum!

I am attempting to test these caps under an HH Scott amp for leakage. I have the Sencore set to "All Other Capacitors".

So far I have used the leakage test on two caps, for one it gives no reading on any voltage selected and just stays on zero. Dropping down the the light to uA, made sure one end was soldered off the board.

The next cap I decided to test for leakage was I assumed rated for 25v DC, however the Sencore meteter continuously blinks past applied 3v. When 3v is selected, only then does it give me some sort of reading that begins to drop.

Only problem is it's not supposed to be a 3v cap, and won't allow me to test any further. Is this of any indication that the Sencore is broken, or just bad caps?

 

[kellys_eye]

Blimey! I'd be replacing that electrolytic no matter what it reads!

 

[Shakedown St.]

Trying to see if these are new caps underneath, if it was already restored so want to test them all. Not including that old cap of course. Scott 121c's should have the old bumblebee caps, looks to have been replaced at one point.

If anyone knows what a zero reading means on those Sencores, help is much appreciated.

 

[kellys_eye]

Have you tried to RTFM?

http://dedisol.unsads.com/~squalyl/kurteries/manuals/Other/SENCORE LC53 OPS.pdf

They aren't 'new' capacitors by any means. Even New Old Stock (NOS) would be a bad idea given their age - as far as the electrolytics are concerned.

If you want to maintain originality then the standard practise is to 'stuff' the old capacitor i.e. remove the old innards and fit a modern equivalent inside.

 

[Shakedown St.]

Exactly what I have been experincing, fuse has never been replaced so would not hurt to swap in a new one.

 

[Shakedown St.]

They aren't 'new' capacitors by any means. Even New Old Stock (NOS) would be a bad idea given their age - as far as the electrolytics are concerned

I have been told film caps can last deacdes, if those had been swaped on in the last decade or so they may still be working you don't say?

 

[kellys_eye]

Film capacitors should be fine - I should have clarified that I was referring to the electrolytic in the 'orange' case....

 

[Shakedown St.]

Film capacitors should be fine - I should have clarified that I was referring to the electrolytic in the 'orange' case....

The Sencore should be able to test those film caps correct? Also, those orange caps on the board are not film?

I will report back the result of switching out the fuse when it's replacement arrives in the mail.

 

[kellys_eye]

The 'orange' capacitor in your earlier post (the one marked 25 25 DC) is an electrolytic, not film. These are particularly noted to dry out over time and replacement is usually standard practise for ALL such types in any equipment that you want to have longevity in.

In older equipment they are virtually guaranteed to be the cause of either failure of the equipment or peculiar operation!

 

[Shakedown St.]

You have stated those orange capacitors are

The 'orange' capacitor in your earlier post (the one marked 25 25 DC) is an electrolytic, not film. These are particularly noted to dry out over time and replacement is usually standard practise for ALL such types in any equipment that you want to have longevity in.

In older equipment they are virtually guaranteed to be the cause of either failure of the equipment or peculiar operation!

I see, thought you were refering to the "orange drops" on photo #6.

 

[Shakedown St.]

Alright, it is noted that you must turn the BNC input counterclockwise to access the fuse, what do you use to turn it? It appears to be pretty suck on there, it takes an odd 7/32 wrench I have coming in the mail that may work.