Sony Receiver smells chemical  - Page 1
Forum section: electronics / repair

author: Benji01
author_rank: Contributor
timestamp: February 01, 2025, 08:47:37 pm
content: Hey Guys,I recently bought a Sony STR 7055. After repairing it, and after some preventive maintenance the receiver works really well.The only big problem that I encountered is that the receiver smells somewhat like a chemical plant.It's a salty and bad electronics smell, i have quite a lot of vintage electronics and none of them smell like that.When you are directly over the receiver you can't smell anything but the whole room smells like it.I washed out all PCB's and everything with two diffrent PCB cleaners and even 99% IPA but nothing seems to work.I even heated it up for a couple of hours but still no change.Does someone has an idea what could cause the smell or how to remove it?

author: m k
author_rank: Super Contributor
timestamp: February 08, 2025, 07:18:02 am
content: Divide it and put different parts to sealed bags.After few hours you should be able to sniff which bag has it.Ozonation is one process for removing odors.Pretty difficult if it's deep inside a wooden cover.

author: silly sausage
author_rank: Regular Contributor
timestamp: February 08, 2025, 07:21:04 am
content: caps pissed there pants?

author: Haenk
author_rank: Super Contributor
timestamp: February 08, 2025, 08:25:52 am
content: I agree, that's either components running hot (thermal camera to the rescue), burning away dust or insulation - or leaking caps.

author: Gyro
author_rank: Super Contributor
timestamp: February 08, 2025, 10:28:21 am
content: Quote from: silly sausage on February 08, 2025, 07:21:04 amLeaking electrolytic, or the previous owner had an old, incontinent cat. They like to sleep on warm objects!

author: RoGeorge
author_rank: Super Contributor
timestamp: February 08, 2025, 10:58:22 am
content: I've seen something similar with some furniture shelves, after 10-20 years of indoors use with no smell. At some point the lacquer started to develop a bad smell by itself (those shelves were empty, nothing was stored there). It was a smell that reminded of fish, maybe rotten meat and cheese brine, hard to describe. Overall, a very unpleasant smell, though the smell was obvious only when sitting less than a meter away. Washing the shelves did nothing. It was the lacquer itself that started to smell out of the blue.The only way to get rid of that smell was to replace the shelves.

author: Haenk
author_rank: Super Contributor
timestamp: February 08, 2025, 11:06:09 am
content: Quote from: RoGeorge on February 08, 2025, 10:58:22 amNever underestimate the amount of Formaldehyd and probably "some other evil stuff" released by 80s/70s/60s furniture. The lacquer or veneer only holds it back for a couple of years, eventually it is released into the air.Though decomposing lacquer is quite possible as well.

author: akku46
author_rank: Newbie
timestamp: February 08, 2025, 11:50:49 am
content: I have a benchtop power supply which emits horrible plastic-like smell when it warms up. When it was new it used to do that even when cold. It still does it after about 20 years when warm.It's so strong that I believe it might be bad for one's health.Your smell problem probably has a different source. But it is surprising how long some plastics or coatings keep oozing their additives out.

author: pbarton
author_rank: Frequent Contributor
timestamp: February 09, 2025, 08:20:01 pm
content: Class-X and Class-Y capacitors are safety-certified and generally designed and used in AC line filtering in many electronic device applications. These safety capacitors are also known by other names, including EMI/RFI suppression capacitors and AC line filter safety capacitors.RIFA X and Y safety capacitors are known to cause a bad chemical smell, once they age.The capacitors are constructed with self extinguishing properties and contain some foul chemicals.

author: Benji01
author_rank: Contributor
timestamp: March 02, 2025, 04:19:05 pm
content: Hi, thank you all for your replies.I disassembled the receiver and submerged the PCB's in techspray PCB cleaner.The cleaner discolored, and it looked yellowish but the smell still is there.As a last efford i submerged the PCB's in heated distilled water with a dishwasher tab. The cleaner started to eat away the soldermask.The smell reduced but the smell is still present and is still way to smelly to be used in a living room.The film caps paralled to the rectifier diodes burned at one point. So the next thing I will try is to destroy a capacitor of the same kind and will check if that caused the smell.So if you have any other things to try i'm happy to test them, but as of now i will throw the receiver away because the smell is too strong.