An interesting finding as I'm going through the OSCON + electrolytic capacitors on the board..
OSCONs:
At grid position H8 on my OR840, there are 4, 8mm diameter Sanyo OSCONs here (marked C8H1, C8G6, C8H3, and C8H2). These are, best I can tell, Sanyo 10SP270M's, rated at 10V, 270uF.
The larger 10mm diameter OSCONs are rated at 4V/820uF.
I've studied all of the pictures in this thread and I only see capacitors rated at 470uF installed there. There are some other more subtle differences in components, namely that the tantalum capacitors on my board seem to be a mish-mash of Vishay, AVX and Kemet, whereas the other boards I see in the thread are a little more consistent.
There is also a slight difference in board layout between the processor slots; the same 10 capacitors are installed, however there is no silkscreen for an additional 2 caps.
Electrolytics:
In the corner at J9 there is a 25V, 22uF cap, and between the power connectors at H6, 25V 100uF.
According to what I believe is a date code sticker on the chip located on the voltage regulator "mezzanine", this board was manufactured around the 44th week of 1999.
I'm attaching the spec sheet for the Sanyo OSCON SP series, since this took a while to dig up.
Big question: what if I installed 470uF capacitors in place of the 270uF ones?