Home |
Search |
Today's Posts |
|
Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
#1
Posted to sci.electronics.repair
|
|||
|
|||
When yellow glue goes brown ...
Sounds a bit like one of those late night cable programs "When Good Snakes
Go Bad" :-) We have discussed this topic on here a number of times, and one thing that usually comes up is how you get the stuff off. There's a switcher that I do which has a pair of small radial electrolytics 'folded over' and glued down on top of a whole bunch of surface mount components on the small drive / control sub-board. Some of the components that are under the glue run quite hot - a zener for instance - and this has a double whammy effect on the board in that first it turns the glue brown, which then becomes conductive, and then it also does a nice job of conducting the heat into the caps, to ultimately **** those as well. The glue gets right down between the pins of the PWM / driver IC amongst other places, and is an absolute bitch to remove, without damaging assorted gnat's-bollock sized support components in the vicinity. Well, today, quite by accident, I discovered that my favoured flux removal chemical - Servisol Deflux 160 aerosol - does a nice job of softening the glue up. Not quite to the point of actually dissolving it, but enough that it can then be fairly easily picked off with a fine scalpel blade, and then scrubbed off with an old toothbrush, once you've got the thick of it off. Arfa |
#2
Posted to sci.electronics.repair
|
|||
|
|||
When yellow glue goes brown ...
On Tue, 11 Sep 2012 17:42:06 +0100, "Arfa Daily"
wrote: Well, today, quite by accident, I discovered that my favoured flux removal chemical - Servisol Deflux 160 aerosol - does a nice job of softening the glue up. Nice find. http://www.farnell.com/datasheets/1323625.pdf Looks like it's mostly naptha (white gas, Coleman fuel, etc) and ether. I vaguely recall finding that the yellow crud is an acrylic, which is attacked by both naptha and ethers. MEK or acetone would work better but would probably wreck other parts on the PCB. http://www.alibaba.com/product-gs/482344777/One_component_solvent_resistant_flame_retardant.ht ml http://www.aliexpress.com/store/product/accept-sample-order-wholesale-flame-retardant-yellow-adhesive-free-shipping-for-you/906248_439369255.html http://www.sonycid.jp/en/products/mc4/sc121.html -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#3
Posted to sci.electronics.repair
|
|||
|
|||
When yellow glue goes brown ...
"Arfa Daily" wrote in message ... Sounds a bit like one of those late night cable programs "When Good Snakes Go Bad" :-) We have discussed this topic on here a number of times, and one thing that usually comes up is how you get the stuff off. There's a switcher that I do which has a pair of small radial electrolytics 'folded over' and glued down on top of a whole bunch of surface mount components on the small drive / control sub-board. Some of the components that are under the glue run quite hot - a zener for instance - and this has a double whammy effect on the board in that first it turns the glue brown, which then becomes conductive, and then it also does a nice job of conducting the heat into the caps, to ultimately **** those as well. The glue gets right down between the pins of the PWM / driver IC amongst other places, and is an absolute bitch to remove, without damaging assorted gnat's-bollock sized support components in the vicinity. Well, today, quite by accident, I discovered that my favoured flux removal chemical - Servisol Deflux 160 aerosol - does a nice job of softening the glue up. Not quite to the point of actually dissolving it, but enough that it can then be fairly easily picked off with a fine scalpel blade, and then scrubbed off with an old toothbrush, once you've got the thick of it off. Arfa Thanks, I've a pair of Tannoy powered monitors caked in the stuff. As luck would have it I've just finished a can of Deflux 160. These Tannoy still have a lot of the original yellow in it, I was wondering WTF I was going to do about it because it does not want to shift easily at all. They have used it everywhere. Cheers, Gareth. |
#4
Posted to sci.electronics.repair
|
|||
|
|||
When yellow glue goes brown ...
Arfa Daily wrote: Sounds a bit like one of those late night cable programs "When Good Snakes Go Bad" :-) We have discussed this topic on here a number of times, and one thing that usually comes up is how you get the stuff off. There's a switcher that I do which has a pair of small radial electrolytics 'folded over' and glued down on top of a whole bunch of surface mount components on the small drive / control sub-board. Some of the components that are under the glue run quite hot - a zener for instance - and this has a double whammy effect on the board in that first it turns the glue brown, which then becomes conductive, and then it also does a nice job of conducting the heat into the caps, to ultimately **** those as well. The glue gets right down between the pins of the PWM / driver IC amongst other places, and is an absolute bitch to remove, without damaging assorted gnat's-bollock sized support components in the vicinity. Well, today, quite by accident, I discovered that my favoured flux removal chemical - Servisol Deflux 160 aerosol - does a nice job of softening the glue up. Not quite to the point of actually dissolving it, but enough that it can then be fairly easily picked off with a fine scalpel blade, and then scrubbed off with an old toothbrush, once you've got the thick of it off. Is there a MSDS for that chemical? |
#5
Posted to sci.electronics.repair
|
|||
|
|||
When yellow glue goes brown ...
p.s.
I also find Deflux 160 great for removing permanent marker etc from mixing desks. (the usual precautions to be applied with plastics) Gareth. |
#6
Posted to sci.electronics.repair
|
|||
|
|||
When yellow glue goes brown ...
Gareth Magennis wrote: p.s. I also find Deflux 160 great for removing permanent marker etc from mixing desks. (the usual precautions to be applied with plastics) I use a citrus based solvent for that. 'Goo Gone Pro Power' http://googone.com/GG-Browse-Products/Goo-Gone-Quart http://googone.com/c.983960/site/gg/..._Pro_Power.pdf |
#7
Posted to sci.electronics.repair
|
|||
|
|||
When yellow glue goes brown ...
"Michael A. Terrell" wrote in message news Arfa Daily wrote: Sounds a bit like one of those late night cable programs "When Good Snakes Go Bad" :-) We have discussed this topic on here a number of times, and one thing that usually comes up is how you get the stuff off. There's a switcher that I do which has a pair of small radial electrolytics 'folded over' and glued down on top of a whole bunch of surface mount components on the small drive / control sub-board. Some of the components that are under the glue run quite hot - a zener for instance - and this has a double whammy effect on the board in that first it turns the glue brown, which then becomes conductive, and then it also does a nice job of conducting the heat into the caps, to ultimately **** those as well. The glue gets right down between the pins of the PWM / driver IC amongst other places, and is an absolute bitch to remove, without damaging assorted gnat's-bollock sized support components in the vicinity. Well, today, quite by accident, I discovered that my favoured flux removal chemical - Servisol Deflux 160 aerosol - does a nice job of softening the glue up. Not quite to the point of actually dissolving it, but enough that it can then be fairly easily picked off with a fine scalpel blade, and then scrubbed off with an old toothbrush, once you've got the thick of it off. Is there a MSDS for that chemical? Yes, several at the bottom of this page http://uk.farnell.com/servisol/10001...0ml/dp/3821470 One little 'rider' that I should attach to this, as there seems to be more than a little interest, is that the choice of toothbrush is quite important. Cheapo clear coloured plastic supermarket jobs are a no-no with Deflux 160. The bristles just fall out in very short order. I always use a 'Reach' brand which is white plastic with rubber grips built into the handle. These are completely untouched by the '160, and last until the bristles are worn down to stubs. Actually, this one http://www.boots.com/en/Reach-Interd...othbrush_1235/ Arfa |
#8
Posted to sci.electronics.repair
|
|||
|
|||
When yellow glue goes brown ...
Arfa Daily wrote: "Michael A. Terrell" wrote in message news Arfa Daily wrote: Sounds a bit like one of those late night cable programs "When Good Snakes Go Bad" :-) We have discussed this topic on here a number of times, and one thing that usually comes up is how you get the stuff off. There's a switcher that I do which has a pair of small radial electrolytics 'folded over' and glued down on top of a whole bunch of surface mount components on the small drive / control sub-board. Some of the components that are under the glue run quite hot - a zener for instance - and this has a double whammy effect on the board in that first it turns the glue brown, which then becomes conductive, and then it also does a nice job of conducting the heat into the caps, to ultimately **** those as well. The glue gets right down between the pins of the PWM / driver IC amongst other places, and is an absolute bitch to remove, without damaging assorted gnat's-bollock sized support components in the vicinity. Well, today, quite by accident, I discovered that my favoured flux removal chemical - Servisol Deflux 160 aerosol - does a nice job of softening the glue up. Not quite to the point of actually dissolving it, but enough that it can then be fairly easily picked off with a fine scalpel blade, and then scrubbed off with an old toothbrush, once you've got the thick of it off. Is there a MSDS for that chemical? Yes, several at the bottom of this page http://uk.farnell.com/servisol/10001...0ml/dp/3821470 One little 'rider' that I should attach to this, as there seems to be more than a little interest, is that the choice of toothbrush is quite important. Cheapo clear coloured plastic supermarket jobs are a no-no with Deflux 160. The bristles just fall out in very short order. I always use a 'Reach' brand which is white plastic with rubber grips built into the handle. These are completely untouched by the '160, and last until the bristles are worn down to stubs. Actually, this one http://www.boots.com/en/Reach-Interd...othbrush_1235/ I like the nylon brush in this set. It is like the old typewriter brushes. http://www.harborfreight.com/3-piece...set-40439.html |
#9
Posted to sci.electronics.repair
|
|||
|
|||
When yellow glue goes brown ...
Arfa Daily wrote:
Sounds a bit like one of those late night cable programs "When Good Snakes Go Bad" :-) We have discussed this topic on here a number of times, and one thing that usually comes up is how you get the stuff off. There's a switcher that I do which has a pair of small radial electrolytics 'folded over' and glued down on top of a whole bunch of surface mount components on the small drive / control sub-board. Some of the components that are under the glue run quite hot - a zener for instance - and this has a double whammy effect on the board in that first it turns the glue brown, which then becomes conductive, and then it also does a nice job of conducting the heat into the caps, to ultimately **** those as well. The glue gets right down between the pins of the PWM / driver IC amongst other places, and is an absolute bitch to remove, without damaging assorted gnat's-bollock sized support components in the vicinity. Well, today, quite by accident, I discovered that my favoured flux removal chemical - Servisol Deflux 160 aerosol - does a nice job of softening the glue up. Not quite to the point of actually dissolving it, but enough that it can then be fairly easily picked off with a fine scalpel blade, and then scrubbed off with an old toothbrush, once you've got the thick of it off. Arfa I hate that stuff, and anybody that ever decided to use it. that silicone caulk they use these days is even more obnoxious. Some seem to have huge amounts of a tough filler. All electronic junk with that stuff should be dumped into the drinking water suppplies in the country that produced it. |
#10
Posted to sci.electronics.repair
|
|||
|
|||
When yellow glue goes brown ...
En el artículo , Arfa Daily
escribió: Well, today, quite by accident, I discovered that my favoured flux removal chemical - Servisol Deflux 160 aerosol - does a nice job of softening the glue up. I've used IPA (isopropanol) and a half-inch paintbrush with all but an inch of the bristles cut off for years. No scraping needed. -- (\_/) (='.'=) (")_(") |
#11
Posted to sci.electronics.repair
|
|||
|
|||
When yellow glue goes brown ...
"Mike Tomlinson" wrote in message ... En el artículo , Arfa Daily escribió: Well, today, quite by accident, I discovered that my favoured flux removal chemical - Servisol Deflux 160 aerosol - does a nice job of softening the glue up. I've used IPA (isopropanol) and a half-inch paintbrush with all but an inch of the bristles cut off for years. No scraping needed. I reckon you must be using either different IPA than me, or dealing with a different yellow glue then ! Before this week's discovery that Servisol 160 has at least a 'softening' effect, and loosens its attachment to the board and the components that it has stuck to, I've never found anything readily to hand that as much as touches it - and I use loads of electronics grade IPA for board and general cleaning. Have I just been unlucky ? Has anyone else found that they can get the stuff off with IPA ? There has been a lot of discussion over the years on this glue, and the effects of it ageing and turning brown, and one of the recurring questions in the threads has always been how to get the stuff off without inflicting damage on the board, hence the reason that I thought it worth passing on this latest finding ... Arfa |
#12
Posted to sci.electronics.repair
|
|||
|
|||
When yellow glue goes brown ...
Arfa Daily wrote in message
... "Mike Tomlinson" wrote in message ... En el artículo , Arfa Daily escribió: Well, today, quite by accident, I discovered that my favoured flux removal chemical - Servisol Deflux 160 aerosol - does a nice job of softening the glue up. I've used IPA (isopropanol) and a half-inch paintbrush with all but an inch of the bristles cut off for years. No scraping needed. I reckon you must be using either different IPA than me, or dealing with a different yellow glue then ! Before this week's discovery that Servisol 160 has at least a 'softening' effect, and loosens its attachment to the board and the components that it has stuck to, I've never found anything readily to hand that as much as touches it - and I use loads of electronics grade IPA for board and general cleaning. Have I just been unlucky ? Has anyone else found that they can get the stuff off with IPA ? There has been a lot of discussion over the years on this glue, and the effects of it ageing and turning brown, and one of the recurring questions in the threads has always been how to get the stuff off without inflicting damage on the board, hence the reason that I thought it worth passing on this latest finding ... Arfa You've omitted the biggest problem , itself or its breakdown product going conductive over time. |
#13
Posted to sci.electronics.repair
|
|||
|
|||
When yellow glue goes brown ...
En el artículo , Arfa Daily
escribió: I reckon you must be using either different IPA than me, or dealing with a different yellow glue then ! Possibly. I'll look up the RS part number when I get back into work and post back here with it. Just gentle scrubbing with the paintbrush and plenty of IPA, leave it a while, go back and it (the brown/yellow goo) falls off. It doesn't dissolve. The silicone-based stuff is another story, however... hence the reason that I thought it worth passing on this latest finding ... Hell yeah, tips always welcome :-) -- (\_/) (='.'=) (")_(") |
#14
Posted to sci.electronics.repair
|
|||
|
|||
When yellow glue goes brown ...
In article , Mike Tomlinson
writes Possibly. I'll look up the RS part number when I get back into work and post back here with it. This is the stuff that works http://uk.rs-online.com/web/p/precis...luids/0180847/ The main constituent seems to be cyclohexane. -- (\_/) (='.'=) (")_(") |
#15
Posted to sci.electronics.repair
|
|||
|
|||
When yellow glue goes brown ...
"Mike Tomlinson" wrote in message ... In article , Mike Tomlinson writes Possibly. I'll look up the RS part number when I get back into work and post back here with it. This is the stuff that works http://uk.rs-online.com/web/p/precis...luids/0180847/ The main constituent seems to be cyclohexane. -- (\_/) (='.'=) (")_(") Noted. Cheers Arfa |
#16
Posted to sci.electronics.repair
|
|||
|
|||
When yellow glue goes brown ...
"Mike Tomlinson" wrote in message ... In article , Mike Tomlinson writes Possibly. I'll look up the RS part number when I get back into work and post back here with it. This is the stuff that works http://uk.rs-online.com/web/p/precis...luids/0180847/ The main constituent seems to be cyclohexane. -- (\_/) (='.'=) (")_(") Ah. So are you saying that it's not in fact IPA that you are using ? Arfa |
#17
Posted to sci.electronics.repair
|
|||
|
|||
When yellow glue goes brown ...
En el artículo , Arfa Daily
escribió: Ah. So are you saying that it's not in fact IPA that you are using ? Yes, apologies. I have both IPA and the above stuff on my bench. The 'stuff' is what works to get rid of the brown goop. -- (\_/) (='.'=) (")_(") |
#18
Posted to sci.electronics.repair
|
|||
|
|||
When yellow glue goes brown ...
On 9/11/2012 11:42 AM, Arfa Daily wrote:
Sounds a bit like one of those late night cable programs "When Good Snakes Go Bad" :-) We have discussed this topic on here a number of times, and one thing that usually comes up is how you get the stuff off. There's a switcher that I do which has a pair of small radial electrolytics 'folded over' and glued down on top of a whole bunch of surface mount components on the small drive / control sub-board. Some of the components that are under the glue run quite hot - a zener for instance - and this has a double whammy effect on the board in that first it turns the glue brown, which then becomes conductive, and then it also does a nice job of conducting the heat into the caps, to ultimately **** those as well. The glue gets right down between the pins of the PWM / driver IC amongst other places, and is an absolute bitch to remove, without damaging assorted gnat's-bollock sized support components in the vicinity. Well, today, quite by accident, I discovered that my favoured flux removal chemical - Servisol Deflux 160 aerosol - does a nice job of softening the glue up. Not quite to the point of actually dissolving it, but enough that it can then be fairly easily picked off with a fine scalpel blade, and then scrubbed off with an old toothbrush, once you've got the thick of it off. Arfa Seems like word would have got around about glue on PCB's. I remember Sony having a service letter about problems caused by glue on 3/4" Umatic VCR machines in the 70's. "or was that the 1/2" reel to reel video recorders" :-) Mikek |
#19
Posted to sci.electronics.repair
|
|||
|
|||
When yellow glue goes brown ...
"Mike Tomlinson" wrote in message ... En el artículo , Arfa Daily escribió: Ah. So are you saying that it's not in fact IPA that you are using ? Yes, apologies. I have both IPA and the above stuff on my bench. The 'stuff' is what works to get rid of the brown goop. -- (\_/) (='.'=) (")_(") OK. That makes sense then, Mike. I thought I wasn't going mad ! I use a lot of IPA, and I was certain that it didn't touch the yellow glue. Seems like the stuff from RS that you are using, acts on it in much the same way as the Servisol 160 - that is that it sort of softens it to 'marzipan', and breaks its bond to whatever it's stuck to. Not perfect by any means, but better than trying to just pick the stuff off ... Arfa |
#20
Posted to sci.electronics.repair
|
|||
|
|||
When yellow glue goes brown ...
"amdx" wrote in message ... On 9/11/2012 11:42 AM, Arfa Daily wrote: Sounds a bit like one of those late night cable programs "When Good Snakes Go Bad" :-) We have discussed this topic on here a number of times, and one thing that usually comes up is how you get the stuff off. There's a switcher that I do which has a pair of small radial electrolytics 'folded over' and glued down on top of a whole bunch of surface mount components on the small drive / control sub-board. Some of the components that are under the glue run quite hot - a zener for instance - and this has a double whammy effect on the board in that first it turns the glue brown, which then becomes conductive, and then it also does a nice job of conducting the heat into the caps, to ultimately **** those as well. The glue gets right down between the pins of the PWM / driver IC amongst other places, and is an absolute bitch to remove, without damaging assorted gnat's-bollock sized support components in the vicinity. Well, today, quite by accident, I discovered that my favoured flux removal chemical - Servisol Deflux 160 aerosol - does a nice job of softening the glue up. Not quite to the point of actually dissolving it, but enough that it can then be fairly easily picked off with a fine scalpel blade, and then scrubbed off with an old toothbrush, once you've got the thick of it off. Arfa Seems like word would have got around about glue on PCB's. I remember Sony having a service letter about problems caused by glue on 3/4" Umatic VCR machines in the 70's. "or was that the 1/2" reel to reel video recorders" :-) Mikek Indeed. It's been discussed on here many times over the years, and the fact that it goes brown, and breaks down into something else that is both conductive and apparently hygroscopic, is well known amongst service engineers. Yet still manufacturers use it in places where it is definitely not to be recommended, such as sources of heat and high voltage, which seem to exacerbate the problems it causes. Arfa |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
O.T. How to mix yellow, cyan, magenta refill ink to get black/brown? | Home Repair |