I just got my Sencore LC75 in today, and found the culprit to be a 10uF 100V
cap, which was reading a value of a few picofarads, and an ESR of about 436
ohms. All of the other caps tested ok. I think I am going to love this new
addition to my bench!

- Tony

"Jim Yanik" . wrote in message
...
"Tony" wrote in
:

Jim,

If you're ever in the Chicagoland area - I owe you a cold one. I
pulled the caps from the power supply and replaced them with brand new
NTE replacements,

I hope you used low-ESR caps intended for switchers.(105 degF,low ESR)
Otherwise,they will not last long.


and some NOS HV caps I had left over from a laser
power supply project. I also replaced all of the 510K 1/2W resistors
near the HV output stage since they looked like they were overheating
and the epoxy coating was flaking off.


Good,they were a common problem for loss of focus;the carbon film
resistors
would increase in value until they opened.They should be replaced with
0.5W
carbon composition types.

I turned the unit on, and after a suspenseful second or two of
silence, the unit powered up, the LEDs stayed lit, and I got a trace
on the screen!

I'm going to leave the unit on for a few hours to burn it in and see
if it remains stable, but it appears you hit the bull's eye on this
unit. Sometime this week, my Sencore LC75 analyzer should arrive in
the mail from Florida, and I'll be able to determine exactly which
part or parts were faulty.

Thanks again!!

You're welcome,glad to be of help.

BTW,I use(and love) the Dick Smith ESR meter.
Hats off to it's inventor.

--
Jim Yanik
jyanik
at
kua.net