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Post by smokeycigar on Sept 27, 2013 1:35:58 GMT
I have an old MF X10 V3, and have read that it was a good idea to upgrade the capacitors. (As I purchased it 8 years ago) I had an initial question about what Voltage rating to use (63v vs 35v). I asked this question in the X-Zone but my thread was deleted. After investigation I assumed used 35v rating was enough. So I was able to source some Panasonic FC caps. 2200uf and 3900uf. I decided to replace the original with below: 2 * 2200uf (470uf original) 2 * 2200uf (1000uf original) 6 * 3900uf (1000uf original) I replaced the 4 * 2200uf first, and also change the diodes to UF4004s. I tested the unit for a few hours and everything work well. Sound was clearer. Before the upgrade, there was an audible hiss in one of the channels when volume was really high. The above modification fixed the hiss issue also. After this I replaced the 6* 1000uf caps with the 3900uf ones. Tested the unit, but after 20 minutes there was a problem. Oh no, and burning smell emanated from the unit. Power was cut and and the unit taken apart to see what happened. Seems the issue was related to one channel only. 1 of the 2200uf caps had blown it's top 1 of the 3900uf caps was showing signs of failure. 1 of the diodes was burnt to a crisp. (tested the diodes in the channel and seems 2 were failed in a shorted state) I am humbly requesting if anyone could help me with some advice? Some of the questions I have are: 1. could this just have happend due to a one off part failure (a diode or a cap) 2. Might this have happened due to only using 35v rated caps? 3. Might this have happened due to the higher caps drawing to much current through the UF4004s causing it to fail? (they are rated at 1A 400v)
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Post by Deleted on Sept 27, 2013 3:44:26 GMT
A capacitor will blow it's top if it's rated voltage is greatly exceeded, or more likely if it is installed in the wrong direction. This may also destroy diodes. Alex
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Post by smokeycigar on Sept 27, 2013 5:03:08 GMT
Thanks for the reply Alex, greatly appreciated. This MF unit runs 12-0-12 supply, so would have thought 35v cap would have been enough. This might mean that 63v Caps are required. I checked the installation, and the caps were installed correctly. To add I also bypassed it with a 0.22uf WIMA film cap.
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Post by Deleted on Sept 27, 2013 5:54:48 GMT
Thanks for the reply Alex, greatly appreciated. This MF unit runs 12-0-12 supply, so would have thought 35v cap would have been enough. This might mean that 63v Caps are required. I checked the installation, and the caps were installed correctly. To add I also bypassed it with a 0.22uf WIMA film cap. Hi Smokeycigar For a correctly installed 35V electro to blow like that with a much lower supply indicates another problem. Perhaps AC getting into the electro through a faulty diode or a fault in that area ?. I would remove the blown electro and any faulty diodes and check for a short circuit on that supply rail with a DMM. Regards Alex
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Post by smokeycigar on Sept 27, 2013 6:27:41 GMT
I am running a very beefy power supply that I have been using since day one (8 years). It's based on a 160 va toroidal. That would provide plenty of current to cook the components if needed. Looking at the specs, that transformer can supply 6.66a
That's why I was thinking the current draw of all the caps exceeded the 1A of the diodes, shorting them and in turn blowing the caps.
The original caps would be 2 * 470 + 8 * 1000 = 8940uf Upgraded components would be 4 * 2200 + 6 * 3900 = 32200uf
Does my above argument make sense?
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Post by smokeycigar on Sept 27, 2013 6:35:48 GMT
Sorry, forgot to ask: What the best way to check for a short in the supply rail?
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Post by Deleted on Sept 27, 2013 6:55:12 GMT
For that amount of capacitance you will need to use diodes rated at least 3 Amps. Alex
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Post by smokeycigar on Sept 27, 2013 8:38:30 GMT
That's what I was thinking, instead of the UF4004 I should use UF5404. Would you think higher rated diodes are needed?
Actually the SF37 looks better 3A, 500v and a RRT of 35ns.
I also read that the X-Can cap mods in the X-Zone are reaching this amount of capacitance. I'm assuming that the diodes in these mods also require UF5404s.
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Post by Deleted on Sept 27, 2013 9:10:28 GMT
That's what I was thinking, instead of the UF4004 I should use UF5404. Would you think higher rated diodes are needed? Actually the SF37 looks better 3A, 500v and a RRT of 35ns. I also read that the X-Can cap mods in the X-Zone are reaching this amount of capacitance. I'm assuming that the diodes in these mods also require UF5404s. How about we wait for Mike to chime in here ? He is the MF modification expert. Alex
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Post by smokeycigar on Sept 27, 2013 9:32:18 GMT
I would love to hear Mike's opinions I currently have a X-can also modified to this capacitance, that has been tested and working. I am not using it anymore until I determine is the UF4004's need upgrading. Don't want to fry this unit either Or maybe the above state capacitance is too much for the X-components.
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Post by PinkFloyd on Sept 27, 2013 9:41:20 GMT
I would love to hear Mike's opinions I currently have a X-can also modified to this capacitance, that has been tested and working. I am not using it anymore until I determine is the UF4004's need upgrading. Don't want to fry this unit either Or maybe the above state capacitance is too much for the X-components. I can't remember the voltages as I don't have a V3 to hand but if you measure the voltage over the 35V caps it's way more than 35V. I always suppy 63V volt caps in my kits. Sounds to me like the caps blew as there was far too much voltage going through them (for them to handle). All the best, Mike.
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Post by smokeycigar on Sept 27, 2013 10:16:44 GMT
Thanks for the reply Mike.
I did notice in some of your mods (pictured in the work in progress thread) that you did use 35v rated caps replacements (the 2 * 470uf). The cap that blew was the replacement for the 470uf ones. Therefore, assumed it would be good for me to do so the same. (use 35v ones) The MF originals were all 63v rated.
The 6 * 1000uf replacements in your mods always look like 63v rated caps.
Do you think the UF4004 diode are under speced for such a large capacitance? (as in only 1A rated)
I will be modding my units to SF type diodes anyway (as they have faster recovery 35ns compared to 50ns)
Before the unit blew sound was great (especially the bass)
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Post by PinkFloyd on Sept 27, 2013 12:52:50 GMT
Thanks for the reply Mike. I did notice in some of your mods (pictured in the work in progress thread) that you did use 35v rated caps replacements (the 2 * 470uf). The cap that blew was the replacement for the 470uf ones. Therefore, assumed it would be good for me to do so the same. (use 35v ones) The MF originals were all 63v rated. The 6 * 1000uf replacements in your mods always look like 63v rated caps. Do you think the UF4004 diode are under speced for such a large capacitance? (as in only 1A rated) I will be modding my units to SF type diodes anyway (as they have faster recovery 35ns compared to 50ns) Before the unit blew sound was great (especially the bass) I have never used 35V / 470uF in the X-10 V3 unless it was by mistake.... can you point me to these pictures? You probably will want to go greater than 1amp diodes with the amount of capacitance you are planning BUT, remember this before you do anything else..... A 63V, 1000uF Panasonic FC measures 16 Dia. x 35.5mm A 63V 2200uF measures 18 Dia. x 35.5mm A 63V 3300uF measures 20 Dia. x 40mm If you are quite happy with "funky angling" then that's fine but if you want to keep the board nice and tidy then you want to stick as close to 16 dia caps as you can find..... you "may" be able to find a 63V / 2200uF with a 16 dia footprint but it will be a much taller capacitor, this doesn't matter in the V3 as there is plenty of headroom....... you certainly don't want to go along the 20 dia route or it will be stuffed like a box of sardines inside and with the "funky angling" you won't be able to fit the caps direct to the board so you are then introducing a fair degree of lead inductance (the leads from your capacitors, due to the length will cause inductance). RS Stock No. 571-672 is a Panasonic FC 1200uF / 63V, Maybe not enough capacitance for your plans but a perfect fit Mike.
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Post by smokeycigar on Sept 27, 2013 13:04:51 GMT
On page ten: rockgrotto.proboards.com/thread/1961/work-progress?page=1013th May 2010 - Andrew's X-10 V3 pictures 6 and 10 - the two black caps (assuming they are pany FMs) are 35v rated The above are the caps that one failed in my unit (35v rated) Picture 9 shows the two 1000uf Samwha VA as 25v rated - these are OK as they are the same Voltage as the original MF caps I'm sure I same other units with 35v caps in these locations.
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Post by smokeycigar on Sept 27, 2013 13:09:40 GMT
Regarding the large 63v capacitors. I'm having issues in sourcing them, the largest I can get my hands on in 63V is 1800 and they are AUD$8. The 1500uf are only AUD$3.60 so might go with these. (18mm dia so ok) The two 470uf replacements will be 1000uf and have dia of 16. So basically it will just fit.
Regarding size, the 470uf replacements can only be 16mm or smaller, while the 1000uf replacements can only be 18mm or smaller.
Regarding the diodes, I will upgrade both my X-can v3 and X10 v3 to 3A ones (probably SF37 or 38)
My X-can v3 runs UF4004s with a total of 32200uf. This was tested and worked for many hours. I will upgrade to (SF37 or 38) ASAP, so no issues arise.
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Post by smokeycigar on Oct 9, 2013 8:59:46 GMT
Hey all,
Quick update.
Purchased some FC caps in 1800uf and 1000uf. Took this long for all of them to arrive. Replaced the 2 original 470uf to 1000uf 63v Replaced the 6 original 1000uf to 1800uf 63v Replaced fried diodes and tested the others.
Quick test power on for 10 minutes with nothing attached. Everything seems to be ok, no overheating or burning smells. Opened her up and examined the new components, all looks as they should be.
Connected to Cyrus CD8 -> X10 V3 -> XCAN V3
Powered them on, everything works, no issues with audio.
Let see what happens after a extended burn in period.
Fingers crossed
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Post by smokeycigar on Nov 1, 2013 11:55:13 GMT
HI all,
Just an update. unit is functioning great after many hours of use. Fingers crossed it stays this way.
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