Jump to content

Recommended Posts

Posted

Hi all, I'm wondering if anyone has any experience with the ESA 942.711 digital movement and can help me figure out what's causing it to not work?  When I received it it was obvious there was a battery leak at some point. The battery connection (see photo) has corroded and fell off, so I soldered a new connection using a led leg.  After removing the black plastic cover to have a look at the IC (I think that's what it's called) I found some more corrosion. Iv'e attempted to repair the corrosion and cleaned it up.  For some reason I can only get  numbers on the lcd when I melt the solder on each solder spot on the top of the board. Then if I remove the batteries and put them back it it disappears again. I'm trying to figure out why heating up the solder joints gets the lcd semi working :unsure: 

c0248f11-b017-4b0d-8c41-03d42cae9319.jpg

DSC_4580.JPG

DSC_4592.JPG

9fd19b41-e9c1-4051-8c21-1fe935a7e7c6.jpg

Posted (edited)
6 hours ago, LexLuther said:

Hi all, I'm wondering if anyone has any experience with the ESA 942.711 digital movement and can help me figure out what's causing it to not work?  When I received it it was obvious there was a battery leak at some point. The battery connection (see photo) has corroded and fell off, so I soldered a new connection using a led leg.  After removing the black plastic cover to have a look at the IC (I think that's what it's called) I found some more corrosion. Iv'e attempted to repair the corrosion and cleaned it up.  For some reason I can only get  numbers on the lcd when I melt the solder on each solder spot on the top of the board. Then if I remove the batteries and put them back it it disappears again. I'm trying to figure out why heating up the solder joints gets the lcd semi working :unsure: 

c0248f11-b017-4b0d-8c41-03d42cae9319.jpg

DSC_4580.JPG

DSC_4592.JPG

9fd19b41-e9c1-4051-8c21-1fe935a7e7c6.jpg

Hi, I have never had one of these in. However it appears from your photo that the LCD is powered through an elastomer flexible contact strip. If this is the case then remove the elastomers and thoroughly clean them in Isopropyl alcohol and the glass contact area as well. If this is the problem then this treatment should cure it. Careful with that soldering iron !!!! Regards, Mike. PS. You may need to put a small insulator under the -ve battery terminal ??

 

Edited by ecodec
More info.
  • Like 1
Posted
21 hours ago, ecodec said:

Hi, I have never had one of these in. However it appears from your photo that the LCD is powered through an elastomer flexible contact strip. If this is the case then remove the elastomers and thoroughly clean them in Isopropyl alcohol and the glass contact area as well. If this is the problem then this treatment should cure it. Careful with that soldering iron !!!! Regards, Mike. PS. You may need to put a small insulator under the -ve battery terminal ??

 

Thanks for the reply. Iv'e cleaned the flexible contact strip before. I was going to give it a better clean, but Iv'e just ruined it. Iv'e accidentally knocked a few wire bonds off of the chip, lesson learnt :wacko: I'm going to try and repair it, although it's going to be like doing surgery on an ant. I'm not even sure what glue to use?

I'm interested in knowing what the insulator does?  

Posted
3 hours ago, LexLuther said:

Thanks for the reply. Iv'e cleaned the flexible contact strip before. I was going to give it a better clean, but Iv'e just ruined it. Iv'e accidentally knocked a few wire bonds off of the chip, lesson learnt :wacko: I'm going to try and repair it, although it's going to be like doing surgery on an ant. I'm not even sure what glue to use?

I'm interested in knowing what the insulator does?  

Normally it stops the -ve battery contact shorting out.

  • Recently Browsing

    • No registered users viewing this page.
  • Topics

  • Posts

    • Yep…This makes perfect sense. With that large a gap in the serial numbers, they were almost certainly machined on different equipment, hence one should have no expectation of any cross-batch compatibility. I’ll revert to the original bridge. Regarding bending the bridge @nevenbekriev, I’ll give it a try, but I may have to buy some better calipers. My Vernier calipers are only accurate to 0.1mm. Not very accurate. 
    • Yes, what I wanted to say is that the cock is part of the main plate, manufactured together with it and not meant to be interchangeable. Even if the other cock gets in place, it is not sure that the balance then will stay upright. You should use the original cock when it exists and is not destroyed. The adjustment needed by bending it is not irreversible. It is minimal deforming that is needed. No tools are needed. I have pointed to all needed references here for the balance staff endshake checking and correctness confirmation. The only tool needed for the correction is You thumb. The cock must be fixed on the main plate, no need of special plate with holes and so on. If You will feel more confident, then measure with Vernier caliper the height of the top of the cock where the stones are against the main plate bottom when the shim is fitted and try to reach the same height when bending the cock (with no balance in place!!!) Caliper with screw for fixing is perfect.    
    • Thanks for the reply. I polished the head of the screw using 1500 to 10000 lapping paper and a screw polisher. This is why I think the head blued and the rest of the screw didn't. Silly question, how do you polish the whole screw inc threads, if that's what it needs to blue? 100% clean, Elna red and heated ultrasonic bath + IPA rinse. Finally, there is definitely heat leak as there's about a 30c difference between the brass bed and the soldering station temp. Having said that, the bed temp was stable. I will try to search out a better brass pot, but I haven't found one yet, hence the stainless steel bowl. 
    • Agreed but that's where WD40 excels, water displacement. 
    • I would change the container to a thick walled brass one to start with. Looking at you screw pictures they don’t look shiny enough, really it’s best to do a black polish on them before trying. Also make sure once polished they are scrupulously clean, I dunk my experiments in acetone before bluing.   i think the thin walled stainless container to leach away the heat from the shavings, most successful bluing videos for example use thick walled brass to hold a good deep amount of shavings which acts as a better holder of heat.   Tom
×
×
  • Create New...