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Post by drumace on Feb 8, 2024 1:53:20 GMT -5
Hi guys, Today I noticed my XPA-1L (gen2) does not have the standby amber light on and seemed like as it was shut down using the power button on the back (which it wasn’t). I also noticed the voltage detector led is barely on (like it’s not getting enough power). I opened up the chassis and noticed the control circuit has a few stains on it (blue and orange) around some resistors. I don’t see any leak from the big black capacitors. I checked the 2 fuses and they were fine. About a year ago I had a different problem with the amp (would go into standby a second after it is turned on and a blinking amber light) and received the schematics from Emotiva. The fix which was done by a professional technician locally was to adjust the bias. Before I send it to inspection (which has a cost involved), how complicated does this sounds like to fix?Hi guys, Today I noticed my XPA-1L (gen2) does not have the standby amber light on and seemed like as it was shut down using the power button on the back (which it wasn’t). I also noticed the voltage detector led is barely on (like it’s not getting enough power). I opened up the chassis and noticed the control circuit has a few stains on it (blue and orange) around some resistors. I don’t see any leak from the big black capacitors. I checked the 2 fuses and they were fine. Before I send it to inspection (which has a cost involved), how complicated does this sounds like to fix? Thank you. Attachments:
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Post by PaulBe on Feb 8, 2024 8:07:39 GMT -5
Hi guys, Today I noticed my XPA-1L (gen2) does not have the standby amber light on and seemed like as it was shut down using the power button on the back (which it wasn’t). I also noticed the voltage detector led is barely on (like it’s not getting enough power). I opened up the chassis and noticed the control circuit has a few stains on it (blue and orange) around some resistors. I don’t see any leak from the big black capacitors. I checked the 2 fuses and they were fine. About a year ago I had a different problem with the amp (would go into standby a second after it is turned on and a blinking amber light) and received the schematics from Emotiva. The fix which was done by a professional technician locally was to adjust the bias. Before I send it to inspection (which has a cost involved), how complicated does this sounds like to fix?Hi guys, Today I noticed my XPA-1L (gen2) does not have the standby amber light on and seemed like as it was shut down using the power button on the back (which it wasn’t). I also noticed the voltage detector led is barely on (like it’s not getting enough power). I opened up the chassis and noticed the control circuit has a few stains on it (blue and orange) around some resistors. I don’t see any leak from the big black capacitors. I checked the 2 fuses and they were fine. Before I send it to inspection (which has a cost involved), how complicated does this sounds like to fix? Thank you. I've never seen a resistor leak any color - they can turn black and char the circuit board in close proximity. The blue looks like copper corrosion. Leakage usually comes from electrolytic capacitors. Send it in for service. At this point, you have more going on than just the electrolytic caps. |
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KeithL
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Post by KeithL on Feb 8, 2024 14:33:32 GMT -5
Resistors don't leak... since they're quite solid. However, as someone mentioned, copper tends to corrode blue or green... What you've got there looks like something dripped onto the board from the top... Corrosion can occur quite rapidly if something conductive drips onto a board that has power on it... (Both the component leads, and the "foils" on and in the board, are usually copper... so they corrode blue or green.) It's POSSIBLE that simply cleaning the board well, being especially sure to remove the actual corrosion, and any remaining sticky traces of liquid, might solve the problem... (Both any liquid, and the corrosion itself, would be conductive, and could cause a fault.) Unfortunately, it's also possible that components have been damaged, or that board foils have been eaten away. (I've seen cases like this where whole foils were gone... or where components were entirely missing legs.) I hate to be gross but... - salt water will corrode like that - animal urine and vomit will corrode like that - so will the water that drips out the bottom of a flower pot after you water the plant - and so will some drinks like coffee and tea Hi guys, Today I noticed my XPA-1L (gen2) does not have the standby amber light on and seemed like as it was shut down using the power button on the back (which it wasn’t). I also noticed the voltage detector led is barely on (like it’s not getting enough power). I opened up the chassis and noticed the control circuit has a few stains on it (blue and orange) around some resistors. I don’t see any leak from the big black capacitors. I checked the 2 fuses and they were fine. About a year ago I had a different problem with the amp (would go into standby a second after it is turned on and a blinking amber light) and received the schematics from Emotiva. The fix which was done by a professional technician locally was to adjust the bias. Before I send it to inspection (which has a cost involved), how complicated does this sounds like to fix?Hi guys, Today I noticed my XPA-1L (gen2) does not have the standby amber light on and seemed like as it was shut down using the power button on the back (which it wasn’t). I also noticed the voltage detector led is barely on (like it’s not getting enough power). I opened up the chassis and noticed the control circuit has a few stains on it (blue and orange) around some resistors. I don’t see any leak from the big black capacitors. I checked the 2 fuses and they were fine. Before I send it to inspection (which has a cost involved), how complicated does this sounds like to fix? Thank you. |
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Post by marcl on Feb 8, 2024 14:37:40 GMT -5
Resistors don't leak... since they're quite solid. However, as someone mentioned, copper tends to corrode blue or green... What you've got there looks like something dripped onto the board from the top... Corrosion can occur quite rapidly if something conductive drips onto a board that has power on it... (Both the component leads, and the "foils" on and in the board, are usually copper... so they corrode blue or green.) It's POSSIBLE that simply cleaning the board well, being especially sure to remove the actual corrosion, and any remaining sticky traces of liquid, might solve the problem... (Both any liquid, and the corrosion itself, would be conductive, and could cause a fault.) Unfortunately, it's also possible that components have been damaged, or that board foils have been eaten away. (I've seen cases like this where whole foils were gone... or where components were entirely missing legs.) Hi guys, Today I noticed my XPA-1L (gen2) does not have the standby amber light on and seemed like as it was shut down using the power button on the back (which it wasn’t). I also noticed the voltage detector led is barely on (like it’s not getting enough power). I opened up the chassis and noticed the control circuit has a few stains on it (blue and orange) around some resistors. I don’t see any leak from the big black capacitors. I checked the 2 fuses and they were fine. About a year ago I had a different problem with the amp (would go into standby a second after it is turned on and a blinking amber light) and received the schematics from Emotiva. The fix which was done by a professional technician locally was to adjust the bias. Before I send it to inspection (which has a cost involved), how complicated does this sounds like to fix?Hi guys, Today I noticed my XPA-1L (gen2) does not have the standby amber light on and seemed like as it was shut down using the power button on the back (which it wasn’t). I also noticed the voltage detector led is barely on (like it’s not getting enough power). I opened up the chassis and noticed the control circuit has a few stains on it (blue and orange) around some resistors. I don’t see any leak from the big black capacitors. I checked the 2 fuses and they were fine. Before I send it to inspection (which has a cost involved), how complicated does this sounds like to fix? Thank you. But as I learned during one of my Coop jobs in school, assembling data recorders at RCA .... resistors do burn quite well, with a flame that can put a hole in a circuit board, and with quite impressive smoke!!  |
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Post by leonski on Feb 8, 2024 17:46:23 GMT -5
Doesnt' look like it got HOT, which will turn the resistor or UNDER it to charcoal. Black and crisp, anyway?
Something dripping from above makes a certain twisted sense, too......Thanks Keith.....I wouldn't have thought that!
Sort of does look like something 'ran' which was wet or liquid? AND it appears to be in 2 places, NOT connected...
so it was 2 events if 'dripping'......
But ONE thing which is just slightly possible? Tech used a solder with a corrosive / acidic flux.
As for cleaning?
First? Make certain it is UNPLUGGED for at least an hour or more. This'll give the large caps a chance to self-discharge.
Next? WEAR EYE PROTECTION. Get PLENTY of light on the subject. LOTS of light to the edge of needing sunglasses.
Again? Use Q-tips. Try a variety of solvents. I'd start with 90% or better Isopropyl.....(Rubbing Alcohol)
MIGHT end up trying Nail Polish remover. But THAT is a last resort.
GET a Hand Magnifier for closeup looks.
UNPLUG the connectors with colorful wires first. They only go in one way, but keep your pics handy for reassembly.
Change Q-Tips frequently as they get contaminated and than use a hair dryer on LOW to force-air dry.......Sniff for fumes coming off the
assembly and do NOT cook it......
If Iso doesn't clean it? Try some FLUX REMOVER......That'll confirm my idea or not.....Which I HOPE is just gas.....
I'd ALSO carefully look at the case top over where the defects are. Look for a glass 'ring' where a soda or something was placed....
Also inspect under the cover for the same kind of evidence.
PRETEND you are Sherlock Holmes.....
And FINALLY? Blue? Copper Phosphate is that color. And can be formed IF soda got spilled into the unit. Soda has Phosphoric
Acid which will react with Copper.....
Got any KIDS who drink soda and play the stereo? Neighbors or friends who would do such a thing?
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Post by leonski on Feb 12, 2024 16:53:31 GMT -5
Drumace!
Please update?
I see in one pic the philips head screw (black oxide?) SEEMS to be missing part of the washer under it.....
And is very 'blue' which may mean acidic attack.....
I'd love to know how this turns out.....
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KeithL
Administrator
Posts: 10,261
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Post by KeithL on Feb 12, 2024 17:46:38 GMT -5
From the picture it does look like that edge of the washer is gone. (Although it could just be obscured under some of the gunk.) However, generally, when you see corrosion that heavy, it is the result of electrical activity through a conductive liquid. Basically, current flows between components, through the liquid, which causes a sort of accelerated corrosion via a process similar to electroplating. There are no acids present inside an amplifier that would cause that sort of corrosion... (Also, the screw is steel; that blue corrosion came from something copper, like a component leg, or a foil trace.) Drumace! Please update? I see in one pic the philips head screw (black oxide?) SEEMS to be missing part of the washer under it..... And is very 'blue' which may mean acidic attack..... I'd love to know how this turns out..... |
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Post by leonski on Feb 12, 2024 19:27:24 GMT -5
'Blue' copper is one of the reaction products from Phosphoric Acid. (Copper Phosphate) This is used in the process of manufacture / bottling of stuff like PEPSI and COKE. Both of those sodas are GREAT Chome Cleaners on old-school cars. That and the SUGAR is a guaranteed income for your Dentist..... www.ncbi.nlm.nih.gov/pmc/articles/PMC4808596/#:~:text=Phosphoric%20acid%20is%20added%20to,and%20functions%20as%20a%20preservative. How's it GET there is of course, the question. Spill a drink and don't tell the boss? A little 'over spill' when pouring in the first place? In ANY event, if I catch anyone using my stereo as a drink coaster, they'll be lucky to just get a few broken fingers as a reward. Any 'conductive liquid' which IS in a conductive state must be grounded at one end, methinks? The philips head screw may be grounded.....and connected to a big copper ring trace on the board......Than into the chassis? What is common practice? I worked on Acid Processors for years....long after they should have been in a toxic landfill. Entire connectors of Molex type (remember them?) would be eaten away. I'd get the thing on the bench, and while wearing elbow length latex gloves and a face shield, spritz the connectors down with a solution of baking soda and DI water. Same thing I do THESE days if I get roped into changing a car battery...... AWFUL toxic mess. Rebuilding a male / female pair of Molex connectors is an awful afternoon.... I could settle some of this in 30 seconds with some PH Paper and distilled water. IF the OP was paying attention, we could learn more after His investigation. Even using a toothpick to scrape away some of the bad stuff Might help? Me? I'd START by undoing the philips head screw. I'd want to see what's UNDER it...... |
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Post by drumace on Feb 12, 2024 20:10:48 GMT -5
I gave the amp to my local technician and he also think this is a result of some liquid spill. This is a mystery to me because I never allow any foods or drinks in my theater room.
The only explanation I have is perhaps the carpet deep cleaning machine which might have somehow sprayed a few drops right in that particular area. While this seems unlikely to me, I honestly have no other explanation. The cleaning solution in the carpet cleaning machine is mostly water with about 10% vinegar, which might explain the rust.
I’m hoping the technician will be able to fix the board without too much trouble…
I’ll keep posting with any updates.
Thank you all.
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Post by leonski on Feb 13, 2024 2:13:06 GMT -5
Vinegar has a ph in the 2->3 range, which is in line with coke or pepsi.
But you'd have a dilute solution......which is to the good as far as 'acidity' goes.
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Post by drumace on Mar 7, 2024 20:21:05 GMT -5
Apologies for the very late response. The amp is back to life. The technician cleaned the board, replaced a few small parts like diodes. The cost was less than what I expected (about $120 USD).
If anyone is looking for a technician in Manitoba Canada, please PM.
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Post by leonski on Mar 8, 2024 1:37:35 GMT -5
Now? Who set WHAT on top of the amp?
Glad this worked out and for a reasonable sum.......
Carry On!
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