Bottlehead Forum
Bottlehead Kits => S.E.X. Kit => Topic started by: JosephDuffy on February 09, 2014, 10:24:54 AM
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Hi,
I've just finished installing the C4S upgrade, and when I turned it on on of the LED blew (D1). It literally broke in half and part of the plastic went flying off. I've done all my visual checks and I can't see any issues, so I'm not too sure what to check. I guess my 2 questions are:
How do I get another LED?
How do I check what I've messed up?
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For a replacement LED just call BH HQ tomorrow or send an email to [email protected] . Before you install the new LED, inspect the orientation of the LED's and transistors. Make sure your leads are going to the correct terminals. Post pics!!
Cheers,
Geary
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Flying electronic components is usually a sign of too many volts, it should only see a few volts. Assuming the amp worked fine before installing the C4s i would read through the manual again from the start and double check every component is installed the correct way.
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The resistor R2 is what limits the current in D1 and D2. If it's the wrong value, or shorted out by a solder blob, that is another possible cause of the symptom. Good idea to make sure D2 is good - personally, I'd ask for two and replace both. But check all the things already mentioned before you try to blow them up again! :^)
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Thanks for all the replies guys. I'm about to send them an email. I've uploaded a couple of photos to Imgur, and double checked against the instructions and I still can't see anything that's wrong. I can't see anything that's shorted and everything oriented correctly. I will note that I originally put the blue resistors in the holes closer to the edge (as show, they're still soldered), but I fixed this before turning it on.
I have also checked the connections that the wires coming off make and the joints look fine and are in the correct position. One thing that threw me off about those was the "Attach and solder the white wire to 11U. Touch up the solder joint at 11L if needed" on page 13, which confused because it talked about both 11U and 11L, but I checked against the photos and the white wires are in 11U and 23U.
Thanks for all the replies guys. Are there any tests I can do now/next time with the multimeter without turning it on?
Quick Edit: Since I'm in the UK it might be quicker for me to just order some LEDs myself. These (http://www.ebay.co.uk/itm/HLMP-6000-Avago-Technologies-LED-Submin-Red-/141102815937?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item20da621ac1) have the same name and look the same so I might as well just order these, for the sake of a few quid?
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Thanks for all the replies guys. I'm about to send them an email. I've uploaded a couple of photos to Imgur, and double checked against the instructions and I still can't see anything that's wrong. I can't see anything that's shorted and everything oriented correctly. I will note that I originally put the blue resistors in the holes closer to the edge (as show, they're still soldered), but I fixed this before turning it on.
I have also checked the connections that the wires coming off make and the joints look fine and are in the correct position. One thing that threw me off about those was the "Attach and solder the white wire to 11U. Touch up the solder joint at 11L if needed" on page 13, which confused because it talked about both 11U and 11L, but I checked against the photos and the white wires are in 11U and 23U.
Thanks for all the replies guys. Are there any tests I can do now/next time with the multimeter without turning it on?
Quick Edit: Since I'm in the UK it might be quicker for me to just order some LEDs myself. These (http://www.ebay.co.uk/itm/HLMP-6000-Avago-Technologies-LED-Submin-Red-/141102815937?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item20da621ac1) have the same name and look the same so I might as well just order these, for the sake of a few quid?
Imgur link?
The reference to 11L/21L is just to double check the joints in case they came undone while unsoldering the resistor from the upper positions 11U/21U and soldering the C4S wires to them. They are joined together so its possible the heat could transfer and unsolder them.
I'm not 100% on the circuit, unfortunately they didn't put it into the manual but if you measure resistance from each white wire to the LED's you should see some sensible resistance, i'm going to guess ~150k assuming those resistors are there to drop the voltage supply to the LED's. Basically use the good side as your reference and look for differences.
LED's you linked look like the correct ones, "pcarena-bristol" generally have a quick turn around in my experience.
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Thanks for all the replies guys. I'm about to send them an email. I've uploaded a couple of photos to Imgur, and double checked against the instructions and I still can't see anything that's wrong. I can't see anything that's shorted and everything oriented correctly. I will note that I originally put the blue resistors in the holes closer to the edge (as show, they're still soldered), but I fixed this before turning it on.
I have also checked the connections that the wires coming off make and the joints look fine and are in the correct position. One thing that threw me off about those was the "Attach and solder the white wire to 11U. Touch up the solder joint at 11L if needed" on page 13, which confused because it talked about both 11U and 11L, but I checked against the photos and the white wires are in 11U and 23U.
Thanks for all the replies guys. Are there any tests I can do now/next time with the multimeter without turning it on?
Quick Edit: Since I'm in the UK it might be quicker for me to just order some LEDs myself. These (http://www.ebay.co.uk/itm/HLMP-6000-Avago-Technologies-LED-Submin-Red-/141102815937?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item20da621ac1) have the same name and look the same so I might as well just order these, for the sake of a few quid?
Imgur link?
The reference to 11L/21L is just to double check the joints in case they came undone while unsoldering the resistor from the upper positions 11U/21U and soldering the C4S wires to them. They are joined together so its possible the heat could transfer and unsolder them.
I'm not 100% on the circuit, unfortunately they didn't put it into the manual but if you measure resistance from each white wire to the LED's you should see some sensible resistance, i'm going to guess ~150k assuming those resistors are there to drop the voltage supply to the LED's. Basically use the good side as your reference and look for differences.
LED's you linked look like the correct ones, "pcarena-bristol" generally have a quick turn around in my experience.
Oops, I had the URL copied, but forgot to put it in. Here's the link (http://imgur.com/a/RM3qa), and I also edited the original for anyone reading that.
I'll take a look at the resistance, but I've feeling that because of the broken LED it won't be a full circuit anyway, so it might not be any good? I should be able to check the resistance across the resistors, which would confirm that they're working I guess.
I assume that that's what they were referencing to with the 11/21/U/L, which I did check, but I thought I'd double check, thanks :)
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Thanks for all the replies guys. I'm about to send them an email. I've uploaded a couple of photos to Imgur (http://imgur.com/a/RM3qa), and double checked against the instructions and I still can't see anything that's wrong. I can't see anything that's shorted and everything oriented correctly. I will note that I originally put the blue resistors in the holes closer to the edge (as show, they're still soldered), but I fixed this before turning it on.
I have also checked the connections that the wires coming off make and the joints look fine and are in the correct position. One thing that threw me off about those was the "Attach and solder the white wire to 11U. Touch up the solder joint at 11L if needed" on page 13, which confused because it talked about both 11U and 11L, but I checked against the photos and the white wires are in 11U and 23U.
Thanks for all the replies guys. Are there any tests I can do now/next time with the multimeter without turning it on?
Quick Edit: Since I'm in the UK it might be quicker for me to just order some LEDs myself. These (http://www.ebay.co.uk/itm/HLMP-6000-Avago-Technologies-LED-Submin-Red-/141102815937?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item20da621ac1) have the same name and look the same so I might as well just order these, for the sake of a few quid?
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I dont see anything obvious, but double check the three pins on the small round transistor on the B side in case they are shorting out.
Doesn't look like the resistor measurement i mentioned above will work, circuit is very different than i thought.
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I dont see anything obvious, but double check the three pins on the small round transistor on the B side in case they are shorting out.
Doesn't look like the resistor measurement i mentioned above will work, circuit is very different than i thought.
This is something I checked a few times since the gap is so small and I remember messing that up when I did soldering in school. I can't see anything that's a possible cause of a short, so I've pretty much ruled that out.
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It looks like you have a solder blob shorting the 2N2907 on the "B" side.
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It looks like you have a solder blob shorting the 2N2907 on the "B" side.
Admittedly, that does look like it's got a bridge across 2 connectors, but I can assure you that it's not. I've tried to take a better photo but I've not got good light right now (it's night time now) and I can't get it to focus.
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Hi guys.
I got my LEDs today, and I've now re-soldered it on. I've uploaded a couple of pictures to Imgur:
http://imgur.com/svHUCbc
http://imgur.com/rzWei5f
Can anyone let me know of any resistance etc. checks I can do before I switch this on which could let me know if this is going to pop again? :)
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I think you have a little soldering work left to do. When you heat a joint on a PC board, you want to see the solder actually suck into the hole.
I would also guess that you either have a chilly iron (less than 40 Watts), or that you are using lead free solder (copper or silver bearing). This tends to make the work more difficult.
-PB
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I think you have a little soldering work left to do. When you heat a joint on a PC board, you want to see the solder actually suck into the hole.
I would also guess that you either have a chilly iron (less than 40 Watts), or that you are using lead free solder (copper or silver bearing). This tends to make the work more difficult.
-PB
Thanks for the reply, I now see that a couple of joints hadn't "sucked through" (though some just had too much solder).
After your comments I've gone through and made sure that I could see solder on both sides of the board:
http://imgur.com/xjymLXT
http://imgur.com/V8WQZca
I'm using a 40W (maybe more, not sure) soldering station and turned it up to 400
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If the solder joints look good on the two wires behind the transistor on the left you should trim those wires just to be certain there is no chance of a short.
The joints themselves are hidden by the transistor so just make sure they are soldered properly. And before you turn the amp on again you should go through the resistance checks again.
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If the solder joints look good on the two wires behind the transistor on the left you should trim those wires just to be certain there is no chance of a short.
The joints themselves are hidden by the transistor so just make sure they are soldered properly. And before you turn the amp on again you should go through the resistance checks again.
I have clipped the ends as much as I can, and checked underneath that the joints are good (sorry, I didn't realise that they were covered on the photo!)
I've just done the resistance checks and A5 isn't showing as anything. B5 is showing as 185kΩ. Neither B5 nor the red wire on the circuit board look to be bad joints, but I'll reflow them for the sake of it. Are then any other s I should look at reflowing to try and solve this problem, or any other areas I can look at?
Edit: I've reflowed A5 and the red connector on the board and I'm still seeing nothing on A5 :(
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That is looking much better, nicely done!
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That is looking much better, nicely done!
I'm still no soldering-guru, but I think I've learnt a lot from the S.E.X. kit :) Looking back at it, I shouldn't have been soldering on the day I completed the C4S upgrade; I was a bit too ill to be doing something like that, so I'm sure that didn't help.
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Watch the solder liquify with the iron against both the PCB trace and the component. After it liquifies hold it for 3s (it is a mental count). This gives me good solder joints every time.
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Watch the solder liquify with the iron against both the PCB trace and the component. After it liquifies hold it for 3s (it is a mental count). This gives me good solder joints every time.
As with most things, I did end up finding that spending more time and slowing down actions helped a lot. I think one of my main issues is when soldering on a board and the blob of solder is a little too large and it makes a sort of "flick" as I move the iron away. I'm assuming these are ok, but it'd be better if I used a little desoldering wick?
I've made sure to get good joints over A5, IA (on the circuit board), but there's still nothing showing when I do a resistance check over A5. Is this expected/safe to turn on/anything else I can be checking to try and find the dodgy joint/component (should one exist)
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Ok, I found something interesting: My 150KΩ that's in R2 (B side) is coming up as ~30KΩ, whilst all the other resistors are showing up as their correct values.
I'm guessing I'm going to have to replace that resistor now?
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This would be a pretty unusual situation, and would really only result in very bright LED's.
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This would be a pretty unusual situation, and would really only result in very bright LED's.
I just did a double check and after leaving the probes on either side it slowly climbed. In about 30 seconds it went for 30 to 65, and I only assume that it'll reach the 150 eventually. However, I can't get a reading over A5 or B5 now. Are there any readings I can check on the board itself so I can make sure it's safe to turn on again?
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Right, scrap everything about the resistor; that seems to be ok-ish.
I've done some more tests:
From the red wire to the 3 prongs of the MJE5731A transistor on the B side I get a reading of 0 ohms. However, on the A side (the side that links to A5) I have a reading of 0 on the middle prong, but then no reading on the left nor right prongs. I've re-soldered all 3 prongs with no luck. Is it worth trying to swap them over?
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The A side MJE is reading correctly. Sounds like the B side MJE is shorted. It is either blown or you have solder bridging the three pins.
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The A side MJE is reading correctly. Sounds like the B side MJE is shorted. It is either blown or you have solder bridging the three pins.
I took careful precaution when resoldering yesterday and saw no bridges, so maybe it went when the LED blew originally. I'll take another look when I get home, though.
For now, the only options I've found have a "G" at the end (see: eBay (http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=281207771249&ssPageName=ADME:L:OC:GB:3160)). The model on the board has the "G" at the end, so I'm assuming these will be suitable replacement parts?
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The G just means its a lead free version to keep the tree huggers happy, other than that its the same part.
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If the 5731A is blown then the accompanying 2N2907 may also be blown. Do the same test, measure resistance across each possible pair combination of the three 2907 leads and see if you read 0s or very low resistance (under 100 ohms) on any pair. That will mean it is shorted.
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If the 5731A is blown then the accompanying 2N2907 may also be blown. Do the same test, measure resistance across each possible pair combination of the three 2907 leads and see if you read 0s or very low resistance (under 100 ohms) on any pair. That will mean it is shorted.
I seem to be getting some off readings, so whilst I'm at, I might as well just replace those, too. I've ordered some of these (http://www.ebay.co.uk/itm/5x-2N2907A-PNP-Silicon-Small-Signal-Transistor-2N2907-/180817151730?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item2a198ac6f2#shpCntId). When I get the 5731A replaced I'll do another check and if I'm still getting odd readings then I'll replace the 2N2907 (I know the 5731A won't make a difference, but it will give me some time away")
Thanks for all the help, as usual! :)
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Please do swap out both transistors at once, just to be on the safe side.
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Right, I've replaced the 5731A and 2N2907 transistors and I've still having issues getting any sort of readings. Once I removed the 5731A it seemed to be working as expected when I performed my resistance checks, which seemed a little odd. I've tested the resistors and as I said previously they seem to be ok. I also cannot find any other areas that seem to raise concern.
I'm hesitant to do much more soldering on it since I'm worried that I might start damaging the board after removing/replacing/reflowing so much.
I'm not sure what my next steps could be other, other than getting a replacement kit or simply removing the C4S and getting hold of some of the old resistors and putting them back in place. I'm still hoping that there's something silly that's gone wrong, but after replacing so many components it's just getting more and more confusing.
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Right, I've replaced the 5731A and 2N2907 transistors and I've still having issues getting any sort of readings. [...] I performed my resistance checks, which seemed a little odd.
You can post what you're seeing. "any sort of readings" and "odd" aren't really enough for us to be helpful.
It would probably help to put the 150K resistors back in to be sure the amp is still functional.
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Right, I've replaced the 5731A and 2N2907 transistors and I've still having issues getting any sort of readings. [...] I performed my resistance checks, which seemed a little odd.
You can post what you're seeing. "any sort of readings" and "odd" aren't really enough for us to be helpful.
It would probably help to put the 150K resistors back in to be sure the amp is still functional.
Sorry, maybe the "odd" comment wasn't well formatted. I meant that it was odd that when I removed the 5731A the 5731A itself seemed to be working as expected (i.e. the resistance checks were showing the same as the new one I'd just received)
By "any sort of readings" I mean that I'm unable to get a reading (0 or more) from the OB to either of the side connectors of the 5731A, which is problem that I was having before I replaced the 5731A.
Edit: Sorry, forgot to add: I was going to try and replace the original resistors, but I was struggling to get them out originally so I cut them. I've only had a quick chance to look but I was unable to find replacements that looks suitable. I will take another look, but right now, I cannot replace them. All the resistance checks, other than B5 (the one on the left when it's unsdie-down, not sure if it's A or B), show as they should be from the original S.E.X. manual.
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Right, so here's where I'm at now:
I've taken the 150K resistors from the C4S board and put them back in the main circuit, leaving out the C4S board completely. I've done my checks, turned it on, and am having no issues, so I'm going to installed the Output Transformer Switched kit since I've got some speakers arriving (hopefully) pretty soon.
I can't find any replacements for the 150K resistors so I'm planning on tackling the C4S kit again in a few days.
I took at look at just buying another C4S kit because it feels like starting over again might help, but the postage to the UK is $40. Is there any chance of getting that price down? The kit's fairly light and small and $40 seems a little high?
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I think we could do a USPS Priority flat rate box at the small size, which is still around $25.
The 150K resistor can actually vary quite a bit in value. The maximum resistance that I would recommend would be 330K, and the minimum would be 120K. At 330K, a 1W resistor is OK, at 120K, a 2W resistor will be necessary.
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I think we could do a USPS Priority flat rate box at the small size, which is still around $25.
The 150K resistor can actually vary quite a bit in value. The maximum resistance that I would recommend would be 330K, and the minimum would be 120K. At 330K, a 1W resistor is OK, at 120K, a 2W resistor will be necessary.
If I can get the shipping for $25 then I'll just get a new C4S kit and not bother getting any replacement resistors. How do I go about ordering a new C4S kit with the $25 shipping?
Quick question regarding the Output Transformer Kit: On page 14 it states, when discussing the wires leading from the binding posts to the boards: "Carefully confirm that each black wire is aligned to its respective transformer". How I do I know which transformer each wire should go in to? My kit came with 4 black covers (rather than 2 black and 2 red) so I can't say "the red/black side goes in to the left/right board". It seems to me that it would make sense if the black wire from the left binding post goes in to the left board, and the right in to the right, but I just wanted to confirm that.
Whilst I'm double-checking things, the picture on page 8 has the resistor in the reverse order that the bands are noted as. Do I do that for the resistor that I use? I've got it going "brown, gold, yellow, black, blue" when the board is the right up, from left to right.
Thanks, again, for all the help you guys have provided!
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My kit came with 4 black covers
Your binding posts have colors... Each set of binding post goes to the transformer it is closest to.
Whilst I'm double-checking things, the picture on page 8 has the resistor in the reverse order that the bands are noted as.
Resistors are not directional parts, this doesn't matter. (But still good that you're paying attention)
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My kit came with 4 black covers
Your binding posts have colors... Each set of binding post goes to the transformer it is closest to.
Whilst I'm double-checking things, the picture on page 8 has the resistor in the reverse order that the bands are noted as.
Resistors are not directional parts, this doesn't matter. (But still good that you're paying attention)
Yeh, the actual binding posts do, but the little plastic covers on either side of the plate are all black, so I couldn't mention the colours that they have. Thanks for the clarification. I'll go over and finish the job now so I can do all the tests.
I'd noticed that resistors seemed to be put in any direction, but thanks for confirming that that applies for all of them!
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I got the Transformer Kit installed and working, and after the "practice" on the C4S board, it was a lot easier to solder! :)
I'm a bit more convinced that I should be able to (successfully) complete the C4S kit, so how do I go about getting the reduced postage costs?
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I would e-mail the request to Eileen and she can send you a Paypal invoice.
-PB
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I would e-mail the request to Eileen and she can send you a Paypal invoice.
-PB
Thanks for all the help! I think we're nearly there :)