I am experiencing a problem with the machine not getting past the initial led flash, it stays on solid.

I read on the pinwiki repair site that when powered on the solenoid driver board C23 capacitor should read very close to 0.30 when the J4 connector is removed from the mpu.

On my stern Nine Ball it shows about 14.68 VDC. I just replaced that cap.

The power supply board readings are about 10% high across the board.

Where should I look next in diagnosing this problem?

Thanks Andrew!

It looks like it’s within spec.

I'm still trying to get beyond the mpu led staying solidly lit on power up. All Header pins have been replaced and no apparent acid damage.

The Mpu test points seem to be within reason at approximately 10% variance.
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My problem of a solidly lit LED on the mpu has resurfaced.

I have a newer mpu (nvram rev 9), the female connectors on the power supply, solenoid driver board, mpu, etc have been repinned and the test points on the PS, SDB and #3-5 on the mpu all appear to be within the reasonable range.

The original -200 mpu had occasionally demonstrated the same locked on led. I sent it to Nabours for a rebuild and it operated fine for a while before I replaced it with a newer nvram mpu.

I’ve been running led displays for well over a year.

edit..Today I swapped in a different solenoid driver board with no difference.

Any suggestions on what to focus on next?

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User error on this one.

I have an older version of the nvram mpu and it requires that a few jumpers be changed using solder blobs. I missed one.