Discussion
I've just opened up my ECU to see if there were any loose joints or anything that could be causing a really nasty flat spot around 3000rpm that I get in the Chimaera after I hit a kurb particularly hard or have an excursion from the island. Couldnt find anything but...
...i have found a mark, almost like a scorch mark on the casing (highlighted by the black splodge of a marker pen) which ties in with the position of the tail from one of the components on the PCB. I've now added a sheet of plastic to try and insulate the component from the caseing.
Just wondering if anyone else had experienced a similar thing?
Also noticed that a capaciter had been touching once of the chips...
Regards
Iain
...i have found a mark, almost like a scorch mark on the casing (highlighted by the black splodge of a marker pen) which ties in with the position of the tail from one of the components on the PCB. I've now added a sheet of plastic to try and insulate the component from the caseing.
Just wondering if anyone else had experienced a similar thing?
Also noticed that a capaciter had been touching once of the chips...
Regards
Iain
The other side of the coin is to wonder whether it'll be able to lose more heat by conduction to the capacitor than by convection to the atmosphere inside the box... but with the particular components indicated, it's not going to be a problem either way. That chip is not going to be generating any significant heat.
Pigeon said:
The other side of the coin is to wonder whether it'll be able to lose more heat by conduction to the capacitor than by convection to the atmosphere inside the box... but with the particular components indicated, it's not going to be a problem either way. That chip is not going to be generating any significant heat.
I thought the chip touching the capacitor was something independent from the scorch mark?
pistol pete said:
chassis 33 said:
...I've now added a sheet of plastic to try and insulate the component from the caseing....
Iain, I hope it's anti-static plastic (probably pink in colour), otherwise you are asking for trouble...
You either want it to conduct or not surly?
As the suspected problem is arcing I'd put an insulator between the component and the metal case.
Cheers guys, sorry for not replying earlier, a lightning strike took out our router at home...and everything connected to a phone line at the office apart from the the router...
The marker pen was put on the scortch mark on the case because the mark didnt show up to well.
What about if I used one of those bags that computer memory and CPU's come in to insulate things?
Regards
Iain
The marker pen was put on the scortch mark on the case because the mark didnt show up to well.
What about if I used one of those bags that computer memory and CPU's come in to insulate things?
Regards
Iain
No, you don't want an anti-static bag, you want something definitely non-conductive that is hard and won't creep. A small square of PET cut from a plastic fizzy drink bottle would do fine.
I thought the chip touching the capacitor was something independent from the scorch mark?
Doh, didn't read your previous post properly. Forget I spoke
Matthew C said:
Pigeon said:
The other side of the coin is to wonder whether it'll be able to lose more heat by conduction to the capacitor than by convection to the atmosphere inside the box... but with the particular components indicated, it's not going to be a problem either way. That chip is not going to be generating any significant heat.
I thought the chip touching the capacitor was something independent from the scorch mark?
Doh, didn't read your previous post properly. Forget I spoke
The component you suspect of scorching the casing is a diode. Quite a few of the components on the board seem to have long tails, including this one. They are in quite close proximity to the case when assembled. If you try to insulate the tails with plastic, they will either pierce the plastic, or, if it is thick enough or strong enough, put the board under strain when you tighten up the casing screws. Obviously this is not desirable. Simply trim the tails (there's a couple of millimetres in some of them). It was designed to be assembled without any such insulation and shouldn't need it. The cover of the casing should have a foam rubber dust seal in it, but this is not always there. Although it does compress when the case is assembled, if it's missing it may well have caused the diode tail to short against the casing, especially after a bump.
The vertically mounted IC next to the electrolytic capacitor in your third picture is not quite vertical on mine and touches the capacitor. It's also been like that since manufacture, as the two components are stuck together with lacquer. This should not cause a problem.
Another tip when reassembling the case: the screws are locking screws with a triangular thread (viewed end on). They tend to create fine aluminium swarf on removal. Make sure none of this is left inside the casing as it really could create havoc in there.
The vertically mounted IC next to the electrolytic capacitor in your third picture is not quite vertical on mine and touches the capacitor. It's also been like that since manufacture, as the two components are stuck together with lacquer. This should not cause a problem.
Another tip when reassembling the case: the screws are locking screws with a triangular thread (viewed end on). They tend to create fine aluminium swarf on removal. Make sure none of this is left inside the casing as it really could create havoc in there.
Gassing Station | Engines & Drivetrain | Top of Page | What's New | My Stuff