Stargate Loss of -5 volts on CPU Board

VectoRaster

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Today I fired-up my Stargate and got an unhealthy looking rug pattern that behaves like it's going through the normal startup ram check, but never stops.

CPU board is throwing a 1-3-1 error code (of course.)

With the CPU board power cable disconnected, the voltages feeding the board are all correct -5, 12, & +5 volts. But when the connector is plugged into CPU board I get about 100 mV everywhere it should be -5 volts (ram and connector pin). 5 and 12 volts stay where they ought to be.

Any ideas?
 
@mecha !

No, just caps like in photo.

I removed the ram (4116) and checked voltage again at the connector and got 5v, 10.69v, & -3.32v.

Do you think it's a power supply issue (it's the original linear power supply)?

Thanks!!
 

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the orange wire at the plug is -5V, measure against the black wires. don't ever under any circumstance try to measure voltage at the rams because you won't like what happens when you cross +12V or -5V places they're not supposed to be. if you have that voltage present at the plug and it's not getting to the DRAM section then the solder to the header pins may be cracked. I personally don't bother resoldering those skinny round pins and just install new headers, along with replacing the filter caps and the power plugs.

if anyone reading this has a Rev. D board with the stand up floppy inductors and voltages are missing, check the legs of the inductors as those are prone to breaking off. (the board in my picture has the newer flat inductors that don't flex and bend around)
 
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