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Author Topic: Yamaha G100-112 - Journey  (Read 2001 times)

dlbraly

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Yamaha G100-112 - Journey
« on: July 18, 2018, 08:16:58 PM »
This Yamaha had a think piece of plastic and some kind of thermal paste between a couple of the diodes and a big heat sink.

Do you just use CPU thermal paste?
They are mounted vertically, so if it was something runny it might run down the side.
« Last Edit: July 18, 2018, 11:14:55 PM by dlbraly »

Enzo

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Re: thermal paste for Diodes?
« Reply #1 on: July 18, 2018, 08:32:32 PM »
Photo?

dlbraly

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Re: thermal paste for Diodes?
« Reply #2 on: July 18, 2018, 08:46:57 PM »
guess I need to shrink the photo sizes

dlbraly

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Re: thermal paste for Diodes?
« Reply #3 on: July 18, 2018, 08:53:28 PM »
Try this again

dlbraly

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Re: thermal paste for Diodes?
« Reply #4 on: July 18, 2018, 08:58:27 PM »
wow thats huge
sorry about that

Testing attachment size

dlbraly

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Re: thermal paste for Diodes?
« Reply #5 on: July 18, 2018, 08:59:36 PM »
Note to self 780x585 is better

dlbraly

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Re: thermal paste for Diodes?
« Reply #6 on: July 18, 2018, 09:30:28 PM »
Should I stick to one post and change the subject to just Yamaha G100-112?

phatt

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Re: thermal paste for Diodes?
« Reply #7 on: July 18, 2018, 10:53:06 PM »
Should I stick to one post and change the subject to just Yamaha G100-112?
Yes that would be easier to follow. :tu:

Adding;
Those are not diodes,, them big suckers is Power transistors.
TR311 &TR312 on the schematic.
The white goo is thermal paste, Yes same for CPU's,, all the same stuff.

The plastic pad is a mica isolating washer which isolates the case (which is also the collector) from the heat sink.
The newer pads maybe synthetic types which are are not so brittle but mica works just as well.
The thermal paste is to help transfer the heat from the collector across to the heat sink,,, and Always use it!! :trouble

When you reinstall those power transistors with washer and paste check with meter to make damn sure that the both collectors (The transistor case) is actually isolated from the heat sink otherwise it will end in tears at switch on. :o
Phil.

dlbraly

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Re: thermal paste for Diodes?
« Reply #8 on: July 18, 2018, 11:13:47 PM »
Should I stick to one post and change the subject to just Yamaha G100-112?
Yes that would be easier to follow. :tu:

Adding;
Those are not diodes,, them big suckers is Power transistors.
TR311 &TR312 on the schematic.
The white goo is thermal paste, Yes same for CPU's,, all the same stuff.

The plastic pad is a mica isolating washer which isolates the case (which is also the collector) from the heat sink.
The newer pads maybe synthetic types which are are not so brittle but mica works just as well.
The thermal paste is to help transfer the heat from the collector across to the heat sink,,, and Always use it!! :trouble

When you reinstall those power transistors with washer and paste check with meter to make damn sure that the both collectors (The transistor case) is actually isolated from the heat sink otherwise it will end in tears at switch on. :o
Phil.

Thank You - Will do

dlbraly

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Re: Yamaha G100-112 - Journey
« Reply #9 on: July 18, 2018, 11:15:39 PM »
OK, so changed the subject so that everything will be one place.

dlbraly

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Re: Yamaha G100-112 - Journey
« Reply #10 on: July 18, 2018, 11:18:16 PM »
Some Pictures
Those first ones are the dirty PA board
Then The DC board before and after
« Last Edit: July 18, 2018, 11:21:54 PM by dlbraly »

dlbraly

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Re: Yamaha G100-112 - Journey
« Reply #11 on: July 18, 2018, 11:22:59 PM »
The MA board before and after I put everything back on

Enzo

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Re: Yamaha G100-112 - Journey
« Reply #12 on: July 19, 2018, 02:17:07 AM »
Um, blanking a board like that is not a good idea.  You run the risk of damaging parts in the process and making reassembly mistakes, soldering errors can occur as well.

dlbraly

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Re: Yamaha G100-112 - Journey
« Reply #13 on: July 19, 2018, 07:54:38 AM »
Um, blanking a board like that is not a good idea.  You run the risk of damaging parts in the process and making reassembly mistakes, soldering errors can occur as well.
LOL now you tell me.
Yeah, I'm learning a lot from my mistakes. I should have asked questions before starting was one HUGE mistake. Could have been a quick fix.

phatt

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Re: Yamaha G100-112 - Journey
« Reply #14 on: July 19, 2018, 09:10:58 AM »
Yes, tiss a bit like pulling out the engine because you found a loose wheel nut. :duh
Remember that just about any part on the pcb is replaceable,, except the pcb itself. :o
On old pcb's it easy to de-laminate the pads which can be a nightmare to fix.
So be very careful not to damage the traces and pads. :-X
Phil.