[volt-nuts] HP3468A

[Bob Smither]

gbusg wrote:
> Neil's suggestion (to check the power supplies) is a good one.
> 
> Make sure the +5V, -15V and +15V rails are correct - and use an oscilloscope 
> to check for excessive ripple.

Done.  All the supply rails look good.

> You didn't mention if you have the rechargable battery option (opt. 001), 
> but if so, that adds to the number of possible problems.

The unit does not have that option.

> I definitely would replace the 3 volt lithium cell (BT551) ASAP.

I did this, but no change.  I wonder if the boot process is assuming 
something that has been lost from the RAM.

> Also make sure that the front panel "Reset" button isn't stuck in the 
> pushed-in position.

Reset button?  Don't see that.
>
> If you're lucky, doing all the above will lead to a cure. If not, then it 
> sounds like some other fault is still causing the "RESET" line (at U501) to 
> keep cycling. It doesn't sound like you're getting through the turn-on 
> self-tests far enough to see possible further error codes (e.g., Calibration 
> RAM error, or RAM error, or ROM error, or A/D converter error).

Agreed.

> Let us know how you come-out on it.

Will do.

Thanks for the feedback!
-- 
Bob Smither, PhD                                   Circuit Concepts, Inc.
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Blessed is he who expects no gratitude, for he shall not be disappointed.
   -- W. C. Bennett
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Smither at C-C-I.Com  http://www.C-C-I.Com  281-331-2744(office)  -4616(fax)
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