R205 100 ohm resistor in SR98 starting to get hot and smell

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Re: R205 100 ohm resistor in SR98 starting to get hot and smell

Post by exxos » Fri Nov 16, 2018 11:18 am

Icky wrote:
Fri Nov 16, 2018 11:14 am
Question for Exxos - there is one cap left on the board C206 that does not have a replacement (see cap with dot on top in pic).
Does that also need replacing or is it worth replacing with a new one?
There is a huge thread on this somewhere, basically is purposely not changed..

I think the bottom line was, I tried ceramics, and all sorts on there, and mostly everything I did seem to make it worse if I remember rightly..

So oddly, it is actually better to leave that alone...
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Re: R205 100 ohm resistor in SR98 starting to get hot and smell

Post by Icky » Fri Nov 16, 2018 11:20 am

exxos wrote:
Fri Nov 16, 2018 11:18 am
So oddly, it is actually better to leave that alone...
Thanks - "Don't fix what ain't broke" :)

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Re: R205 100 ohm resistor in SR98 starting to get hot and smell

Post by Icky » Fri Nov 16, 2018 11:23 am

You got to watch those clips on the rectifier and heatsink. Mine just pinged off whilst applying pressure and hit the ceiling.

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Re: R205 100 ohm resistor in SR98 starting to get hot and smell

Post by exxos » Fri Nov 16, 2018 11:29 am

Icky wrote:
Fri Nov 16, 2018 11:23 am
You got to watch those clips on the rectifier and heatsink. Mine just pinged off whilst applying pressure and hit the ceiling.
Sweet! :lol:
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Re: R205 100 ohm resistor in SR98 starting to get hot and smell

Post by Icky » Fri Nov 16, 2018 11:46 am

Just a note - the large rectifier the legs are a little too wide for the holes. Had to drill the original holes a fraction bigger to get the component in.

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Re: R205 100 ohm resistor in SR98 starting to get hot and smell

Post by exxos » Fri Nov 16, 2018 11:48 am

Icky wrote:
Fri Nov 16, 2018 11:46 am
Just a note - the large rectifier the legs are a little too wide for the holes. Had to drill the original holes a fraction bigger to get the component in.
psu.JPG
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4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

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Re: R205 100 ohm resistor in SR98 starting to get hot and smell

Post by Icky » Fri Nov 16, 2018 11:50 am

exxos wrote:
Fri Nov 16, 2018 11:48 am
Icky wrote:
Fri Nov 16, 2018 11:46 am
Just a note - the large rectifier the legs are a little too wide for the holes. Had to drill the original holes a fraction bigger to get the component in.
psu.JPG
Thanks Exxos - You are always one step ahead :)

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Re: R205 100 ohm resistor in SR98 starting to get hot and smell

Post by Icky » Fri Nov 16, 2018 12:19 pm

DONE - Recapped and re-metal filmed

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Re: R205 100 ohm resistor in SR98 starting to get hot and smell

Post by Icky » Fri Nov 16, 2018 12:21 pm

Icky wrote:
Tue Nov 13, 2018 11:10 pm
Power lines under load before metal film resistor replacement:

+5V line= 4.85V
+12V line= 11.26V

Power lines under load after metal film resistor replacement:

+5V line = 4.84V
+12V line = 11.23V

More importantly R205 is not getting really hot and smelling. Thus have solved the heat and smell problem.
Finished measurements (under load) with metal film resistor replacement and recap:

+5V line = 4.92V
+12V line = 11.09V

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Re: R205 100 ohm resistor in SR98 starting to get hot and smell

Post by exxos » Fri Nov 16, 2018 12:34 pm

Icky wrote:
Fri Nov 16, 2018 12:19 pm
DONE - Recapped and re-metal filmed
:bravo:
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
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