Products > Test Equipment

Keithley 2000 issues

(1/2) > >>

MetraCollector:
Hello gentlemen

I bought today Keithley 2000 for about 430$ in local pickup (seller was as young as I am, perhaps he didn't know what he is selling).

Before I turned it on, I looked inside it - nearly burnt 17V zener VR109 - it WORKS at 18.7V and it is really hot.
Then I discovered darker places on the laminate under power components - rectifiers and stabilizers.

My question is - is it normal ? Is there schematic available although it is not provided by Keithley ?
Multimeter works though, but I do not think that heating zener is OK.
I have a bad feeling that some pads were resoldered by someone, perhaps he ran multimeter using 110V voltage selector on our 230V mains.

I would be very grateful for any hints or suggestions.

Thank you and regards Ondrej

nadona:
I found this.
http://circuitslab.case.edu/manuals/Keithley_Model_2000_Multimeter_Repair_Manual.pdf

free_electron:
the first generation of 2000 and 2001 are horrible for this problem...
the diodes blow, the caps leak and explode and eat the traces .....

MetraCollector:
Thank you, I looked in the repair manual and helped a little. Something strange:  +/-15 rails are at about 15.7V
I can also hear some noise, I am not sure if it is VFD boost converter or something else.

All in all - seller didn't want to discount to half price, he wants multimeter back and my colleague wants his money back. :)

nadona:
Noise? What noise? I can't hear anything from mine. DMM doesn't make any noise. You'd better return it.

Navigation

[0] Message Index

[#] Next page

There was an error while thanking
Thanking...
Go to full version