Minolta X-700 electronics: A closer look

[ColinEOS30]

Welcome to Photrio, @ColinEOS30!

I'm afraid not. They're all different, and even if the physical dimensions are the same, there can be big differences. I would not have expected a clear specification to be present in the X700 service manual; no surprise there.


This may be a suitable type. The spectral sensitivity seems appropriate, although there's no chart included and it's of course unknown what the spectral sensitivity is of the original sensor used by Minolta. As you may have noticed, the datasheet of the sensor you found lists two types (VTB8440BH and VTB8441BH), which have very different performance (the latter is far more sensitive). This illustrates what I said above about physical dimensions and performance.

I'm sorry to say that there's probably no reliable way to determine which photodiode could be substituted here, unless you get hold of a product type and accompanying datasheet of the original part used by Minolta.

PS: @Andreas Thale no longer publicly posts on the forum. I suspect he does still read it from time to time and he may respond to your question if he has the answer - which, honestly, I doubt.

Thank you MOD, at some point you answered me on the specs question. I measure the diode on my X700, the size all match the one i shared (Digikey VTB844XXX)
So what i can do is give a good try. I found this VTB844XXX from a redditor who shared, so I hope it works.

Btw i wondering why Andreas no longer active here or not reply publicly anymore? Anything happen?
I searched his work, all great and valuable sharing is very appreciate.

 

[koraks]

So what i can do is give a good try

Yes, certainly. I don't know if this camera has some way of calibrating the meter; I imagine it would have, with the help of tiny potentiometers (I expect two) somewhere on one of the flex boards. A service manual will probably contain the relevant details.

Btw i wondering why Andreas no longer active here or not reply publicly anymore? Anything happen?

He decided to leave. If you ever get the chance to talk to him, he might explain. If he does, keep in mind that the story has multiple sides. You'll hear only one of them.

 

[4season]

Thank you MOD, at some point you answered me on the specs question. I measure the diode on my X700, the size all match the one i shared (Digikey VTB844XXX)
So what i can do is give a good try. I found this VTB844XXX from a redditor who shared, so I hope it works.

Btw i wondering why Andreas no longer active here or not reply publicly anymore? Anything happen?
I searched his work, all great and valuable sharing is very appreciate.

He's currently active on photo.net, working on Canon A-1 and AE-1.