Tektronix 2465A DM TEST 76 FAIL 01

[aa7ae]

The DMM in my Tektronix 2465A went out the other day and now the scope plays "Taps" with the fault message, "DM TEST 76 FAIL 01" displayed.  I opened the scope and checked for loose connection and didn't find any. I also checked the internal and external fuse and that seemed fine. I took out the DMM board and checked the tantalum caps to see if any where shorted, but nothing there either. Does anyone else have some ideas of what might be going on here?

[oventech]

Hello. Found the Service Manual download page. Hope it helps. https://www.tek.com/manual/2465a-and-2467-service-manual

[Monkeh]

That manual doesn't cover the DMM option. This one does, though: https://archive.org/details/tektronix_2465_DMM

[med6753]

This is from the 2465 DMM option service manual. I would assume the 2465A is the same.

[MarkL]

That manual doesn't cover the DMM option. This one does, though: https://archive.org/details/tektronix_2465_DMM

Just in case, here's the manual specifically for the 24x5A series options (GPIB, TV, CTT, WR, DMM):

  https://archive.org/download/tektronix_24x5aOptions_Jun87/24x5aOptions_Jun87.pdf

The explanation of the DMM error is still the same, but the DMM board assembly is a later rev (-07 vs -04) so there might be some circuit changes when you start digging into it.

[kyhsc1815]

same error

a29 board  t5210 transformer .pwr: isolaton hf pot core
component failure   Where can I get it?
same error like my Tektronix 2465dmm

[calibrationfixture]

Hi kyhsc1815,

Sometimes the Big (Inside) Fuse is the Fix:

https://groups.io/g/TekScopes/topic/102589632#msg201824

Calibrationfixture

[kyhsc1815]

I checked the fuse and it was blown.
Even if I put in another fuse, it blew, so I checked again.
c5112/c5111 short c5110 (no capacity) exchange (electrolytic low impedance)
It's finally working. It took 3 years.