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PostPosted: March 5th, 2016, 7:36 pm 
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Hello, I have been waiting for months for ideas on how to fix the power supply unit. Research showed me little information, saying that it's the capacitors that need to be replaced. However, after taking it to one repair shop, people there said I should find a new working PSU, because of repairing being dangerous. But some others said that a repaired PSU lasts longer than a factory fresh one, while PSUs of this kind are next to impossible to find. Shipping to far away repairmen is expensive, so I'm left with a few more local ones, but knowing which is the best is my next thing to figure out. Some said that giving it to a local repairman is crazy, but my parents said leave dangerous tasks to pros.

Please readers, give me ideas.


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PostPosted: March 6th, 2016, 7:01 am 
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If you have no previous experience with electrical or soldering work, DO NOT attempt to fix it yourself. You could kill yourself (seriously).
In most cases, a power supply can be fixed by replacing the capacitors and cleaning up any electrolyte that leaked out from the old caps. A good repair shop will be able to do this even without any particular knowledge of the FM Towns.


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PostPosted: March 8th, 2016, 11:40 pm 
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What capacitor models are in the FM-TOWNS II HR model? Me and my mother contacted a few repair services, and one of them said they must have a look to understand it. They also must know what exact capacitors should be replaced, while they want me to purchase them online to ship them to their location.


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PostPosted: March 9th, 2016, 3:18 am 
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I'd replace ALL electrolitic capacitors (I don't think there's an extravagant number of e.caps on that PSU), if one's not failing yet it will someday. It's dead easy to replace them for any technician, each cap has uF and V values somewhere, you shouldn't need to import or buy anything, the repair service can get the caps in any Radio shack or electronics store.
It's somewhat basic repair stuff.


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PostPosted: March 23rd, 2016, 12:09 am 
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After talking to nearby repair shops, one that focuses only on today's PCs said you might can take it to a TV repairman; however, I found one computer repairman and he said just quoted that he didn't say it was per hour or I think it means by the job that I know he'll spend that much time on it and if he can't fix it for that much time really then he'll let me know that he can't go in and I won't owe him anything. He sounded like a really knowledgeable person as well as a very conscientious one trying to help people with their computer issues.

I also heard that one of them don't recommend trying to solder old motherboards or replace capacitors because it just leads to other problems on down the road not that it's hopeless but he was told that my FM TOWNS II HR model was in pristine condition and had been kept in good environment the entire time I found it it's just that it got too hot and cuts off and he said then it's probably either one of the two things the motherboard or the capacitor PSU.


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PostPosted: March 23rd, 2016, 4:04 am 
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Just my opinion: I think you're hesitating too much for a simple situation..

If you want it to be working OK, either you get the caps replaced and try, or you get a spare PSU to try.
If I understand correctly, you're on a low budget, so I'd go with caps replacement.

Computers are, sometimes, simple stuff to fix (like for example the caps replacement we're talking about). But you have to have the technical knowledge, otherwise you have to pay to someone who does.

You have no more options, I think.


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PostPosted: March 24th, 2016, 12:29 pm 
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Thanks. Do you know what exact capacitors are required for the II HR model?

And you are correct on PSU availability. It's next to impossible to find a working one.

As for repairing the old one, one nearby computer repairman said I should look inside with a flashlight for any leakage or blown capacitors not only in the PSU but also the motherboard.

I also found this info that sounds like my unit's problem: powers off then makes hissing sound.

http://nfggames.com/forum2/index.php?topic=5003.0

My father suggests to take it to this other local repairman that knows even how to replace capacitors from TVs to similar electronics.

If all of this fails, then maybe this April, I can ship it to someone within the US who knows how to repair this unit. Any suggestions?


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PostPosted: March 25th, 2016, 12:24 am 
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Thing is, faulty caps are not easily spotted everytime, because caps can lose some capacity and still work, so really, aside from obvious bad caps (exploded ones, swollen ones, leaked ones) you have to test them with a capacimeter or similar tool.

It's much easier to replace all electrolitic capacitors at once, specially if the repair service doesn't have a capacimeter check. The downside of this approach is less original equipment, and the upside is less failure rate because caps are new. That's just my opinion though, I'm no expert on 30yo+ electronic devices repair...

About which exact caps are needed, each cap has an inscription on one side that indicates the tension (V) and the capacitance (on electrolitics, usually in uF). Example: 400V 330uF The repair dude has to replace the faulty caps with the exact values. All values are commercially available. Radioshack or similar store should have all you need.

Any quality caps will do.

TL;DR: I'd test and replace faulty ones, but replacing ALL is another option.


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PostPosted: March 25th, 2016, 12:57 am 
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1983parrothead wrote:
My father suggests to take it to this other local repairman that knows even how to replace capacitors from TVs to similar electronics.


Yeah. It's pretty basic stuff actually.


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PostPosted: April 7th, 2016, 11:22 am 
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Most of time capacitors suffer from an increased ESR (impedance) due aging of the dielectric although capacitance remain the same.
So, a simple capacitance check could be not enough.Like 'wushu' said, I suggest you to replace them all.


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PostPosted: May 11th, 2016, 8:11 pm 
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Thanks for your suggestions. A friend of mine suggested me to replace the PSU unit with another unit with same watts and plug. What do you think?


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PostPosted: May 11th, 2016, 8:23 pm 
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1983parrothead wrote:
Thanks for your suggestions. A friend of mine suggested me to replace the PSU unit with another unit with same watts and plug. What do you think?


If you mean a same PSU model, it's the best choice.But if you are gonna to replace it with a standard PSU like ATX one most likely you have to adapt it since connector will be different.Besides, you have to check what voltages are coming out from the original PSU, if they are standard ATX ones or not.


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PostPosted: May 12th, 2016, 2:44 pm 
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Finding a new one that's a modern version sounds difficult. Is this enough info?

http://i.imgur.com/i3xCCZW.jpg


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PostPosted: May 12th, 2016, 2:57 pm 
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1983parrothead wrote:
Finding a new one that's a modern version sounds difficult. Is this enough info?

http://i.imgur.com/i3xCCZW.jpg


No, you can't know PSU specs from this label, only the maximum power absorbed which is 120W under full operation (and 60 in normal one).
First of all we need a pinout of the PSU (or connector on motherboard) to know which are the voltages of the original PSU.Then we can study some replacement.Is your original PSU completely dead?


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PostPosted: May 12th, 2016, 3:45 pm 
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To answer your question, yes. My friend inspected it with a magnifying glass and it looks like this:

http://i.imgur.com/zdPIZpm.jpg

It uses a 20 pin connector.


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