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List:       classiccmp
Subject:    Re: Sperry UTS 40 on Ebay - Statesboro, Georgia
From:       Dominique Carlier via cctalk <cctalk () classiccmp ! org>
Date:       2017-07-30 22:30:29
Message-ID: 5f78ae91-e4ba-7a46-3088-a8e96f3e0b3e () skynet ! be
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*I still suspect PSU (not food ^^ bad translator)


On 30/07/2017 22:44, Dominique Carlier via cctalk wrote:
>
> Thanks a lot, but as described in my last post, I finally found the 
> location of the missing battery. I repast the text here:
>
> Yes ! I found it !
>
> ----------------------------------------------------------------
> http://zeltrax.com/classiccmp_forum/06.jpg
>
> You are right, there was indeed a beginning of corrosion with a 
> leaking battery. I had taken it away, I could not remember it at all.
> I still have to find the voltage of this missing battery, do you know 
> it? Otherwise I have this UTS20D, there may also be a battery with the 
> same value ...
>
> So I cleaned the rest of the acid, no damage I think.
>
> http://zeltrax.com/classiccmp_forum/05.jpg
>
> So it would only be the cause of the blank screen? That would be so 
> great !! :-)
> I also disassembled the PSU board, some inflated capacitors, I'm going 
> to replace all these caps. There is also a broken/burned "molex" 
> connector.
>
> I will repair all this and I will post a topic dedicated to the 
> restoration of this machine.
> Thank you all for the information !
> ----------------------------------------------------------------
>
> Unfortunately, in the meantime I replaced a series of capacitors at 
> the end of life, repaired the broken / burned Molex, built a replica 
> of this battery and it does not change anything, I always have a blank 
> screen.
> I still suspect food, something else that seems strange to me is the 
> absence of sound of static electricity when I turn on or off the 
> monitor, the filaments of the CRT collar nevertheless.
> Difficult without schematics
>
>
>
> On 30/07/2017 22:26, jim stephens via cctalk wrote:
>>
>>
>> On 7/30/2017 4:43 AM, Dominique Carlier via cctalk wrote:
>>> Can you tell me where the batteries are supposed to be, on which board?
>>> I disassembled the machine, extracted the 4 motherboards, I did not 
>>> see any batteries anywhere.
>>> If they are externalized, maybe I removed them a long time ago in 
>>> the idea of replacing them, but I have not yet found where they were 
>>> connected in that case.
>>>
>> I don't know there are batteries, but the device had a lot of 
>> configurations which were retained by some means.  1999 was a bit 
>> early for eeproms that didn't have battery backup of some sort.
>>
>> If there are no batteries visible, or large super caps which can back 
>> up memory content, that is a good thing.
>>
>> There may also be Dallas modules in the thing or similar which 
>> integrate batteries.  The components will usually have had a 5 to 10 
>> year lifespan, and probably won't work so well across power cycles.
>>
>> thanks
>> Jim
>>>
>>> On 28/07/2017 11:25, jim stephens via cctalk wrote:
>>>> I do hope you get it going.  If you feel qualified, one thing I'd 
>>>> also look for are packs with batteries to hold information that may 
>>>> have decayed.  That sometimes can cause what you described.  since 
>>>> the system may have been left since 1999, the batteries may have 
>>>> gone onto corrosion and you may have a bit of fixing to do for that.
>>>
>>>
>>
>>
>
>

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