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ST-V parts - need help to identify spares

cyllboy

cyllboy

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Hello to everyone. I need help for a repair on ST-V board.

My board is missing SC1 (photo) that I believe is the super-capacitor for battery-backup: somebody could please tell me a suitable substitute (I do not know the value of the component).

Moreover I noticed some leaky capacitors (FL50 FL49) in the emi filter (maybe I am completely wrong about those components): the square capacitors with 3 legs (are they decoupling capacitors?). Is that kind of components available somewhere or do I need to cannibalize a second board?

I also noticed a missing diode between D1 and D2: is it missing or was never mounted? (photo)

Thank you all in advance!
 

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SC1 is 0.10F 5.5V.

You're missing D2. From left to right, it's R105, D1, D2 and R100 (where a diode has been installed in place of the resistor). All four should be populated.
 
nem said:
SC1 is 0.10F 5.5V.

You're missing D2. From left to right, it's R105, D1, D2 and R100 (where a diode has been installed in place of the resistor). All four should be populated.
Click to expand...
Could you please tell me what array this is? I need to find a replacement. I had one break off. I also have that diode where r100 is. Why would someone do that? Also my HD6417095 SH-2 has 2 broken pins. Can i removed one from a donor Saturn? Thanks
 

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HardAzRockz said:
Could you please tell me what array this is? I need to find a replacement. I had one break off. I also have that diode where r100 is. Why would someone do that? Also my HD6417095 SH-2 has 2 broken pins. Can i removed one from a donor Saturn? Thanks
Click to expand...
I do not have Idea of what is the °S4724, I think that you should find a donor motherboard to pick it.

I suspect that the diode in r100 came in various board: in photos on the net I saw the same thing. "Why would someone do that?" is also my wonder.

Saturn SH-2 is the same: it is extremely difficult to correctly rework a smd processor. You need to use solder with lead in it and flux paste, chisel point and be very careful because you could bridge the pins if you are not expert.


nem said:
SC1 is 0.10F 5.5V.

You're missing D2. From left to right, it's R105, D1, D2 and R100 (where a diode has been installed in place of the resistor). All four should be populated.
Click to expand...

Thank you very much nem: I ask why would someone do that mod (replacing resistor with diode, removing a diode)? Ave you an Idea of what is FL49 (and his brothers) ? Can you confirm my thoughts? Are they some sort of electrolytic capacitor used as filters or are they resonators (and if so... why so many)?

Thank you all, indeed!
 
cyllboy said:
I ask why would someone do that mod (replacing resistor with diode, removing a diode)?
Click to expand...

The diode replacing the resistor is a factory mod. However, the missing D2 isn't normal. Maybe whoever removed the supercap accidentally knocked it off.

As for FLXX, I suspect they're filters.
 
nem said:
The diode replacing the resistor is a factory mod. However, the missing D2 isn't normal. Maybe whoever removed the supercap accidentally knocked it off.

As for FLXX, I suspect they're filters.
Click to expand...
Can you read the value of the diode D2?

And are the LFXX components available nowdays?

Thank you very much!
 
By the way, is there a good source for the slot connector, or a way to bodge an existing connector to at least read the address/data part?
 
cyllboy said:
Saturn SH-2 is the same: it is extremely difficult to correctly rework a smd processor. You need to use solder with lead in it and flux paste.
Click to expand...
I use my hot air station for some SMD ICs but i plan on using a Chip quik low temp solder. Should be easy to remove. As far as soldering it on ill probably use my solder paste. Im no expert but its definitely doable even at my skill level.
 
nem said:
@ic3b4ll has them? See this thread for a right angle adapter he's been working on:

https://www.arcade-projects.com/threads/90-degree-angle-riser-for-the-stv-cart.7429/
Click to expand...
No kidding, they're expensive. I assume this is the correct type:
https://www.digikey.co.uk/product-d...ions/GBB91DHHD-S621/GBB91DHHD-S621-ND/1464519
(And you've got to buy at least 10...)
Too much for the dumping/testing jig I had in mind, but maybe this is useful for someone needing to repair boards in the future. (Though I am not sure if the pins are staggered the right way...)

Edit: Or better this one?
https://www.digikey.co.uk/product-d...ions/GBB91DHHN-S621/GBB91DHHN-S621-ND/1464529

Though I may be able to bodge a PCI connector for dumping.
 
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I told you guys the adapter would be expensive... Now you know why!
Who needs it? I can spare one for just the cost + shipping.
 
ic3b4ll said:
I told you guys the adapter would be expensive... Now you know why!
Who needs it? I can spare one for just the cost + shipping.
Click to expand...
Also you've got to spend money on development, prototypes and manufacture, which is something many people underestimate...

Right now I don't need a proper one, but I may get back to you if I get the adapter designed.
 
Fluffy said:
Also you've got to spend money on development, prototypes and manufacture, which is something many people underestimate...

Right now I don't need a proper one, but I may get back to you if I get the adapter designed.
Click to expand...
I totally agree with you on the development costs... Many people have no idea how long it can take to get a design right even if it's an apparently simple thing and how much it costs to iterate a design.

I'll keep a connector aside for you in case you need one.
 
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