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| Are RIFAs needed for Plus? |
Posted by: 68kPlus on 2022-09-07 20:40:43
Hi,
Just wondering if it's 100% necessary to have C33 and C36 installed on an international Mac Plus AB.
Also, is it true the late Mac Plus' have bleeder resistors? My Plus is from June 1990.
Thanks |
Posted by: bibilit on 2022-09-08 00:01:25
IIRC they are not really required, but they are so cheap i will replace them to keep the board more or less original. |
Posted by: cheesestraws on 2022-09-08 02:20:31
You should replace them if you can. They are not there because the Plus needs them, they're there to stop the Plus feeding crap back into the power network and screwing up other devices. |
Posted by: 68kPlus on 2022-09-08 02:21:27
You should replace them if you can. They are not there because the Plus needs them, they're there to stop the Plus feeding crap back into the power network and screwing up other devices. That makes sense. I have 4x RIFAs for my Plus, but I still need more soldering skills 🙂 |
Posted by: bibilit on 2022-09-08 02:31:58
I still need more soldering skills this is pretty basic to be honest |
Posted by: 68kPlus on 2022-09-08 02:32:55
this is pretty basic to be honest True, but I'm not good at soldering at all. I've never really done through-hole soldering. |
Posted by: 68kPlus on 2022-09-08 02:39:20
You should replace them if you can. They are not there because the Plus needs them, they're there to stop the Plus feeding crap back into the power network and screwing up other devices. Do RIFAs have polarity? |
Posted by: cheesestraws on 2022-09-08 03:03:12
Not unless my memory is really playing tricks on me 🙂 |
Posted by: Iesca on 2022-09-08 03:08:55
Through-hole soldering is very easy. Bruce Rayne has some great tutorials on through-hole and surface-mount. You can also watch Dave Murray (The 8-bit Guy) solder new through-hole caps in a Plus and get the basic idea.
They are definitely recommended, as they're part of a protection circuit, as has been mentioned.
As for the Rifas themselves, you can still buy their modern equivalents. They will even be marked as Rifa, though they are manufactured by Kemet. And no, they are non-polar, so no worries on that front. However, you don't necessarily need Rifa-style caps, you can use any similar X2 and Y2-class film caps, as needed. |
Posted by: Iesca on 2022-09-08 03:13:21
These are the ones I ordered for my Plus (I only needed 3)
0.1 µF, 275V, X2-class (x1)
Digi-key #399-7483-ND (Manufacturer #PME271M610MR30)
4700 pF, 250V 1000V, Y2-class (x2)
Digi-key #399-5411-ND (Manufacturer #PME271Y447MR30) |
Posted by: joshc on 2022-09-08 05:58:52
There is no polarity to RIFAs, insert them either way you like. The most important bit is getting the right type/class and voltage rating. |
Posted by: 68kPlus on 2022-09-08 17:42:42
Through-hole soldering is very easy. Bruce Rayne has some great tutorials on through-hole and surface-mount. You can also watch Dave Murray (The 8-bit Guy) solder new through-hole caps in a Plus and get the basic idea.
They are definitely recommended, as they're part of a protection circuit, as has been mentioned.
As for the Rifas themselves, you can still buy their modern equivalents. They will even be marked as Rifa, though they are manufactured by Kemet. And no, they are non-polar, so no worries on that front. However, you don't necessarily need Rifa-style caps, you can use any similar X2 and Y2-class film caps, as needed. I bought these:
They seem to match 100% the original International AB spec. |
Posted by: 68kPlus on 2022-09-08 17:44:10
There is no polarity to RIFAs, insert them either way you like. The most important bit is getting the right type/class and voltage rating. I'll probably just solder them in the same way the originals are. |
Posted by: 68kPlus on 2022-09-08 17:46:32
These are the ones I ordered for my Plus (I only needed 3)
0.1 µF, 275V, X2-class (x1)
Digi-key #399-7483-ND (Manufacturer #PME271M610MR30)
4700 pF, 250V 1000V, Y2-class (x2)
Digi-key #399-5411-ND (Manufacturer #PME271Y447MR30) My Plus has the later red cap for the 0.1µF RIFA, so it's fine. The two I have are:
- Rated voltage: 250 VAC 50/60 Hz
- Capacitance range: 0.001 - 0.1 µF
I bought them as 4700pf, so they should be fine (let me know if I'm wrong) |
Posted by: Skate323k137 on 2022-09-08 20:22:23
True, but I'm not good at soldering at all. I've never really done through-hole soldering. Strongly recommend at least the 1st video in this series; even knowing how to solder, it did wonders for my worksmanship and consistency. It's also excellent at explaining how and why solder works, how flux works, and what makes a good connection.
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Posted by: Iesca on 2022-09-09 03:56:55
Those vintage Pace videos are great! |
Posted by: Phipli on 2022-09-09 04:02:48
I'll just chip in and say...
Desoldering is more tricky than soldering although you'll still be fine. I'd but a couple of cheap ebay soldering kits (some clocks or christmas trees or something) and build them up, then practice removing some of the components and putting then back.
On a £2 board it won't matter if it goes wrong. |
Posted by: 68kPlus on 2022-09-09 23:30:03
I'll just chip in and say...
Desoldering is more tricky than soldering although you'll still be fine. I'd but a couple of cheap ebay soldering kits (some clocks or christmas trees or something) and build them up, then practice removing some of the components and putting then back.
On a £2 board it won't matter if it goes wrong. I did something similar to what you said. I practised through-hole soldering on a no-good board, and I just succesfully did the RIFA recap!
Thanks everyone for the help! |
Posted by: Iesca on 2022-09-10 00:40:13
Congrats! Definitely a sense of pride when you first learn to do it. 🙂 |
Posted by: Phipli on 2022-09-10 01:07:58
Awesome 🙂 well done. |
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