Tektronix 2465A Channel 1 problem

In fact it is like I have a capacitor in parallel on the ch1 entry.

Yes, that would explain the integration (square to triangle).

Obviously, you have switched the probes?

" snipped-for-privacy@algosyn.com" wrote in news: snipped-for-privacy@a75g2000cwd.googlegroups.com:

you can remove the CH.1 attenuator,take it apart carefully(a plastic frame retains the relays),and use an eraser to LIGHTLY clean the switch pads on the ceramic substrate.

the attenuators are succeptable to outgassing from plastics coating the contact pads. The other part of the switches are the relays,I would not attempt to clean those contacts,maybe spray with a zero-residue/zero lube contact cleaner.

you have to remove the front plastic edge trim to access the screws to pull the front panel,to access the screws to remove the attenuator. there's a procedure in the service manual for atten removal.

New attenuators are no longer available;TEK does NOT support this product series anymore.

Thanks

Yes, I have changed them and also changed the Volts/Div :(

Thank Jim.

I will have a look this wee-end. I have not the schematic of the scope. Do you think I can exchange some parts of Ch1 and Ch2 to locate where is the problem ?

Olivier

You can download a service manual here if you need one: ftp://bama.sbc.edu/downloads/tek/2465a_2467/

" snipped-for-privacy@algosyn.com" wrote in news: snipped-for-privacy@h3g2000cwc.googlegroups.com:

Ch.1 and Ch.2 preamps can be swapped. That and the attens are the whole Channel 1 and 2.

IIRC,the BAMA site has the service manual for download.