Tek TDS3034 input channel failure

[NH-GrizzlyBear]

One input channel works correctly at 1X only. The other three channels work perfectly.

There are two, blue, 2-coil SPST latching relays up front, Panasonic NAIS TK1-L2-4.5V, and a white 2-coil DPDT latching relay behind, Takamisawa ASLD4.5W-K.

I don't know which relay controls 10X switching, 50ohm switching, etc.

pic from Dave's EEVblog -23564 to 23565 - Tektronix TDS3054 Oscilloscope Teardown Repair.
Are there any other pics showing these relays more clearly?

Any insight is appreciated.

[SQ9MT_PL]

I propose to desolder the module (you have to do it anyway)
And desolder the relays and check them.
If the relays are OK, you will have to replace the entire module anyway.

[voltsandjolts]

Refering to the picture posted in the OP, the three latching relays perform these functions:

The blue relay on bottom left switches AC/DC coupling.

The blue relay on bottom right switches 50 Ohm to ground, on output of above relay.

The white relay selects attenuator network for [1,2,5,10,20 mV/div] or the networks for [100,200,500 mv/div] [1,2,5,10 V/div]
The [brackets] represent 3 different signal paths into the custom amplifier / differential adc driver.

The dark green areas are laser trimmed resistors, e.g. the input 50 Ohm terminator resistor is adjacent to the input ac coupling cap (at the very bottom of the module). I have a rough block diagram somewhere, I'll have a look for it.

[bdunham7]

One input channel works correctly at 1X only. The other three channels work perfectly.I don't know which relay controls 10X switching, 50ohm switching, etc.

Could you be more detailed about this issue?  Unless I've misunderstood what you mean,  1X/10X 'switching' is a scaling issue that has nothing to do with the input circuitry.  So what exactly are you observing?

[voltsandjolts]

The module has 58 pins soldered into the multilayer motherboard.
It's a PITA to remove (speaking from experience) so you don't want to do that unless you are sure its broken and you have a working replacement. You are risking damage to the motherboard.
IIRC I repaired my 3034B with a module from a 3034 but there was a slight difference between them. I had to put a short across two of the older module pins to get it working...I think...some years ago now.