2x Keithley 2000 repair log

[frenky]

So I got two abused Keithley 2000 from Israel for total cost of 480€.

Both turn on but none of them works. Yesterday I tried only voltages, then I took both apart to see what is the situation.

One of them stinks really bad and when opened it gets worse. (Not sure if electrolyte has such horrible smell...)

Bot units have a bunch of defective caps with electrolyte spilled all over the board.

First step will be to wash all pcbs and housing with isopropanol so that I can see the real damage on components and tracks/vias. (And to get rid of horrible smell.)

Some pics:

[frenky]

Electrolyte damage:

[Zucca]

Wow that is like a second war world battle field. This board has to drink a lot of distilled water and IPA.

[MadTux]

Remove the electrolytics and the beeper (doen't work anymore if it gets wet) and dump them into the dishwasher.
This is what I usually do with such horrible messed PCBs

[saturnin]

So I got two abused Keithley 2000 from Israel for total cost of 480€.

Are they really worth money you paid? Recently, I bought KEI2000 in working condition and very nice shape for ~250€ shipped...

[frenky]

So I got two abused Keithley 2000 from Israel for total cost of 480€.

Are they really worth money you paid? Recently, I bought KEI2000 in working condition and very nice shape for ~250€ shipped...

Well in if you live in US it's probably easy to get cheap one from ebay.
But most of US sellers don't ship to Europe and if they do, postage is >150$ for such heavy multimeter...

So my plan is to fix both Keithley 2000. Then sell the best looking one (use best parts from both)  and keep the other.

[saturnin]

I am based in Europe It is all about patience. I would not support that Israeli guy. He sells stuff from dumpster for ridiculous prices...

[frenky]

Well I won't feel bad for trying to save equipment from rotting in trash...

Anyway I plan to create new labels for the right part of panel.
So I have re-drawn everything from scratch (it's not 100% as original but it's close enough):

[Smith]

I have ordered some of Keithleys original stickers for an electrometer once, they where something like 12 euro's. I guess the 2000 stickers will be about the same.  Looking at the pictures I guess you need more parts from Keithley, so shipping can be combined.

Any luck on cleaning/repairing the PCB's yet?

[frenky]

I have inspected both boards and made marks on all possibly problematic areas:


Then I removed all capacitors and some voltage regulators:



One of the board no longer have two tracks but luckily there is no tracks on the middle layers...


Next I'll make a list of all components on problematic areas and replace all the cheap ones. 

[frenky]

One board mostly clean...

[tooki]

Well I won't feel bad for trying to save equipment from rotting in trash...

Anyway I plan to create new labels for the right part of panel.
So I have re-drawn everything from scratch (it's not 100% as original but it's close enough):

Oh god, if you're not gonna use Univers, then at least please use the proper Helvetica, not Arial! Travesty!! 

[frenky]

It's not Arial. It's Browallia New. I tested at least 50 fonts to find best match.

So the original is "Univers"? https://en.wikipedia.org/wiki/Univers

[frenky]

This version of Univers seems to be a good match:

[tooki]

It's not Arial. It's Browallia New. I tested at least 50 fonts to find best match.

So the original is "Univers"? https://en.wikipedia.org/wiki/Univers

Browallia New is a Thai font. Its Roman characters are clearly just Arial, which makes sense given that they're both designed by Monotype. So you're just using Arial by another name.

The original is Univers. Not as distinctly noticeable in the words "sense wire", but very obvious in the numerals and the letter K. It was a really popular font here in Switzerland for a long time, most of my school textbooks used it heavily so I'm very attuned to it!

And I'm a typography nerd.

[Dachpappe]

Wow, that's quite the most spilled electrolyte I've seen in a K2000. But good job on the cleaning. You might want to change all affected parts you can get easily. In my leaked battery repair of a Gossen Metrahit Pro I discovered that there is quite a lot of electrolyte and corrosion under the parts which you cannot reach by cleaning the board. Also the solder joints may be problematic as the tin gets eaten away first.
We've got a similar issue in a K2000, but the regulators died due to the electrolyte and a bunch of other stuff got fried.. Do you have the SM or original schematics for the unit on hand? Maybe you can send me a PM. 

[frenky]

You might want to change all affected parts you can get easily.

Yes, will do that.

We've got a similar issue in a K2000, but the regulators died due to the electrolyte and a bunch of other stuff got fried.. Do you have the SM or original schematics for the unit on hand? Maybe you can send me a PM. 

Schematics:
https://xdevs.com/doc/Keithley/2000/K2000.pdf

Repair manual:
https://xdevs.com/doc/Keithley/2000/2000-902-01_B_Mar_1997_Repair.pdf

More docs:
https://xdevs.com/fix/kei2000/#manual

[Dachpappe]

Repair manual:
https://xdevs.com/doc/Keithley/2000/2000-902-01_B_Mar_1997_Repair.pdf

Ah great! Wonder why I haven't found that one before 

[frenky]

Wow the list is longer than expected...



Parts to replace if available (and cheap):

CR115 = DIODE, DUAL SWITCHING, BAV99L(SOT-23) [RF-82]
U119 = IC,NEG VOLTAGE REG -15V,500MA,79M15 [IC-195]
U125 = IC,POS VOLTAGE REG +15V,500MA,7815 [IC-194]
R153 = RES NET, 3.6K MICRO DIVIDER [TF-246-1]
U118 = IC, J-FET, OP-AMP, TLE2081CD(SOIC) [IC-967]
R279 = RES, 1K, 1%, 100MW, THICK FILM (0805)
C222 = CAP, 47P, 5%, 100V, CERAMIC (0805)
C146 = CAP, 2200UF, 20%, 16V ALUM ELEC
U111 = IC,CMOS ANALOG SWITCH DG211DY(SOIC) [IC-768]
U109 = IC, 8 STAGE SHIFT/STORE,MC14094BD(SOIC) [IC-772]
U124 = IC,+5V REGULATOR,500mA,7805 [IC-93]
R277 = RES, 66.5K, 1%, 100MW, THICK FILM(0805)
Q118, Q112 = TRANS, NPN, MMBT3904 (SOT-23) [TG-238]
U117 = IC, VOLT. COMPARATOR,LM311M (SOIC) [IC-776]
R278 = RES, 357, 1%, 100MW, THICK FILM (0805) [R-418-357]
R155 = RES, 4.99K, 1%, 100MW THICK FILM(0805) [R-418-4.99K]
R168 = RES, 270,5%, 250mW, METAL FILM (1210) [R-376-270]
VR109 = DIODE, ZENER 17V, MMBZ5247BL (SOT-23) [DZ-104]
VR110 = DIODE,ZENER 5.1V, BZX84C5V1 (SOT-23) [DZ-88]
C145 = CAP, 1000pF, 20%, 50V, CERAMIC (1206) [C-418-1000P]
Q124,Q126,Q123,Q125,Q120 = TRANS, N CHANNEL JFET, SNJ132199(SOT-23) [TG-294]
R280 = RES, 49.9, 1%, 100MW THICK FILM(0805) [R-418-49.9]
R140 = RES, 1K, 1%, 100MW, THICK FILM (0805) [R-418-1K]
R276, R316 = RES, 10K, 1%, 100MW, THICK FILM (0805) [R-418-10K]
U123 = IC, DUAL PICOAMP OP-AMP AD706JR (SOIC) [IC-910]
Q119 = TRANS,P CHANNEL JFET,J270 (TO-92) [TG-166]
U116 = IC, DARLINGTON ARRAY, ULN2003L (SOIC) [IC-969]
CR114 = DIODE, SWITCHING, MMBD914 (SOT-23) [RF-83]
U131 = IC, QUAD COMPARATOR,LM339D (SOIC) [IC-774]

//Around PRECISION REFERENCE, LM399:
Q129 = TRANS, PNP, MMBT3906L(SOT-23) [TG-244]
Q130 = TRANS, NPN, MMBT3904 (SOT-23) [TG-238]
VR112,VR113 = DIODE, ZENER, 6.2V MMS26V2 SOD-123 [DZ-97]
U139 = IC, DUAL BIPOLAR OP-AMP, LT1124C58 [IC-955]

[pinyoro]

Wow!

[frenky]

Farnell does have a lot of components in stock.

So today mailman brought:
CR115 = DIODE, DUAL SWITCHING, BAV99L(SOT-23) [RF-82]//0,11€
CR114 = DIODE, SWITCHING, MMBD914 (SOT-23) [RF-83]//0,5€ (5pcs)

VR109 = DIODE, ZENER 17V, MMBZ5247BL (SOT-23) [DZ-104] (MMBZ4704-V-GS08) 0,236€ - USA
VR110 = DIODE,ZENER 5.1V, BZX84C5V1 (SOT-23) [DZ-88]// (BZX84C5V1-7-F) 0,211
VR112,VR113 = DIODE, ZENER, 6.2V MMS26V2 SOD-123 [DZ-97]//1,4€ (10pcs) (MMSZ5234BT1G)

Q118, Q112, Q130 = TRANS, NPN, MMBT3904 (SOT-23) [TG-238]//0,4€ (MMBT3904) (10pcs)
Q119 = TRANS,P CHANNEL JFET,J270 (TO-92) [TG-166]//0,3€ (J175_D26Z)
Q129 = TRANS, PNP, MMBT3906L(SOT-23) [TG-244]//0,08€
Q124,Q126,Q123,Q125,Q120 = TRANS, N CHANNEL JFET, SNJ132199(SOT-23) [TG-294]
== MMBF4393LT1 0,46€*5=2,3€

C222 = CAP, 47P, 5%, 100V, CERAMIC (0805) (08051A470JAT2A) 0,7€ 10pcs

caps:
100u 63V 10mm (EEU-FC1J101) 0,64€
C145 = 1000u 50v 13mm x2 (ECA-1HHG102) 5pcs 4,3€
C146 = 2200u 16v 13mm (MCKSK035M222M25S) 0,884€
6800u 16v 18mm  (EEUFC1C682) 2,83€

smd:
10u 25V (T491C106K025AT) 0,856€
22u 25V (293D226X9025D2TE3) 1,03€

tantals on legs:
C171,177 = CAP, 2200P, 10%, 100V CERAMIC [C-430-2200P] (MCRR50222X7RK0100) 0,31€

U118 = IC, J-FET, OP-AMP, TLE2081CD(SOIC) [IC-967]//0,94€
U117 = IC, VOLT. COMPARATOR,LM311M (SOIC) [IC-776]//0,76€
U111 = IC,CMOS ANALOG SWITCH DG211DY(SOIC) [IC-768]//1,42€ (DG211BDY-E3)
U109 = IC, 8 STAGE SHIFT/STORE,MC14094BD(SOIC) [IC-772]//0,45€
U116 = IC, DARLINGTON ARRAY, ULN2003L (SOIC) [IC-969]//0,47€
U131 = IC, QUAD COMPARATOR,LM339D (SOIC) [IC-774]//0,417€