SI Power Board A082-090400-H000 question

[andykmv]

i am looking for a Midway Power Supply board model A082-90400-H000, to go with the matching SI harness** and matching Midway SI L Shaped boardset, and i am having more luck finding everything but that model (missed out on an ebay item recently).
**they both have the Amphenol/Tyco Miniature Rectangular 24 pin connectors - the PCB has the 24 pin "PC Board Vertical
Pin Header" part no 640505-3 (could be the -1 if thinner pcb), and the harness has the part no 1-640525-0 line socket. i would need to get the matching part no 1-640515-0 "pin housing" and pins to make an inline adapter. See Digikey catalogue page http://dkc3.digikey.com/PDF/US2011/P0252.pdf for the parts.

so i have started looking at original power supply boards of similar era as an alternative as i would rather be a masochist and at least get CLOSE to original than put in a switcher!

does anyone have waveform traces of any or all of the 12v line, 5v line, Reset and Sense circuit waveforms of volts vs time during the power supply startup phase, upto and including the 5v rail/reset line stabilising ? useful to check//verify compatibility. From what i have read so far, the pcb wont boot unless there is a working reset circuit.

So far i have looked at the compatibility of :
- the Galaga Power Supply board model A084-90414-C935
SilentNinja has one for sale at the moment. after comparing the schematics for both the A084-90414-C935 (ref the Midway Galaga schematics) and the A082-90400-H000 (re f the Midway SI schematics), i could make up a harness adapter and hack up a reset circuit, but are the Sense circuits compatible ?

 

[orion3311]

As an act of good faith, I'll try to answer this since I'm knee deep in the schematic...

The H000 is a common SI power supply, it has the adjustable 12v. (3 pots total). Should be pretty easy to come by.

Not-so-common-but-should-work is the 80-904 (check part #), which is a Sea Wolf supply. Almost the same deal but 12v is not adjustable.

Wiring wise, the outputs of the supply (5,12,-5 and the only the negative sense line go to the main board connector, which is the 18 pin edge connector. The reset line goes to the larger molex on the daughterboard, and has to be low (I think less than .4 volts) in order to work. You can ground the reset line and chances are it'll work as a test. The reset line stays high for a moment to let the 5v stabilize before starting the board. When the reset circuit fails its usually putting out 1 or 2 volts (in my experience).

The other boards you mentioned are much more involved Midway boards and would be overkill for an SI imo. I've never seen the wiring for a switcher in an SI but I'm assuming they just ground the reset line and the sense line wouldn't be needed/used.

 

[andykmv]

thank you for that info!

also on re-reading the http://elektronforge.com/TestMdwPS.htm i found reference to the reset line behaviour so that is a little more info too.