Repairing Tektronix p7240 probe

[merckhung]

Hi everyone,

I am new to the forum, but I have been interested in repairing Tektronix TDS7000 series and high-speed activate probes (read about a few articles).

Recently I bought a p7240 probe from eBay at a fair price. The owner said the probe is intermittent and noisy (I thought it was acoustic, but later I realized it was actually referring to the signal noise floor)

So, I unscrew the preamplifier box, the first sight is a tiny black wire floating around in the box.
I am not sure did I accidentally pulled it off, or it fell off itself. Does anyone know where this black wire should connect to?

I have been inspecting the pcb board and the gold connector carefully, but could not find any suspicious point this wire might be connected to before it came off.

Thank you, I would appreciate that.

Br,
Merck

[merckhung]

Btw, I found a few datasheets for chips on its pcb board.

OpAmp
https://www.analog.com/media/en/technical-documentation/data-sheets/111214fb.pdf

potentiometer
https://www.renesas.com/us/en/www/doc/datasheet/x9408.pdf

EEPROM
https://www.st.com/resource/en/datasheet/m24c02-w.pdf

Regulator
https://www.ti.com/lit/ds/symlink/lm317m.pdf?ts=1603369627471&ref_url=https%253A%252F%252Fwww.google.com%252F

[Mechatrommer]

i have one just dangling like that. just opened it many months ago to snap pictures whats inside, never got a chance to test or fix it (i bought 2 as is with few others P6243/P6245). download service manual may give you some light (snapshot from page 6 attached) https://download.tek.com/manual/071105600.pdf