Author Topic: Trimble 57963 board repair help needed  (Read 791 times)

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Offline WPXS472Topic starter

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Trimble 57963 board repair help needed
« on: May 19, 2020, 08:42:08 pm »
I wasn't sure where to post this. I found references to this board in several places. But, since I am attempting to repair it, this is where I chose to put it. Sorry if this isn't the right place.
OK, so I bought this off eBay back in April and it just arrived yesterday. Since these are prone to come with components missing, or damaged, I took a look under a microscope. I found L4 missing, what I assume to be R68 missing. It is right under C76. If someone could either send a close up photo of L4, or else describe it, that would help. Also, if someone could measure R48 that would be nice as well. In addition to these, U18 has taken a blow and is cracked. I am looking at sources for the OPA374. I will probably order it from Mouser. So far, I have found a good bit of information on this unit here. It was sold as guaranteed working. The seller's definition of working might be different to mine, but missing and broken components seem to indicate that it probably isn't working correctly. I see no point in powering it up until the missing and damaged components have been replaced.
 

Offline WPXS472Topic starter

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Re: Trimble 57963 board repair help needed
« Reply #1 on: May 21, 2020, 04:19:46 pm »
It seems I was mistaken about R48. The missing component is actually L11. I misread the silk screen. I ordered another, hopefully it will actually have the correct components. And, I will have a spare.
 

Offline WPXS472Topic starter

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Re: Trimble 57963 board repair help needed
« Reply #2 on: June 16, 2020, 02:42:08 pm »
If anyone else has this same issue, I took another one of these to my former employer yesterday and found that L4, L11 are 2.7 uH. I got replacements and will install them as well as the op amp today. SOmething tells me though, that this will not fix this problem.
 

Offline WPXS472Topic starter

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Re: Trimble 57963 board repair help needed
« Reply #3 on: June 29, 2020, 07:14:05 pm »
Well, it seems that replacing the missing and damaged components did repair the unit. I didn't think so for a while, but it finally settled down fairly well. Not the best GPSDO I have seen, but not too bad.
 


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