LumaFix for the C64 (fwd)

[RobertBe]

(Ray wants to spread the word on this.)

----------------------- Original Message -----------------------
Subject: LumaFix
From: Ray Carlsen
Date: Fri, July 6, 2018 1:23 pm
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I noticed nothing about heat sinks was mentioned in the instructions for installation of a Lumafix module. Running a VIC chip with no sink will destroy it. Notice ALL C64's including the SX have a sink on the VIC. One guy said he installed a Lumafix, and his computer kept shutting down. The VIC was of course overheating after the original metal shield was removed. There are other IC's that need protection, and excessive heat will shorten their lives as well. A few weeks ago I installed Lumafix for a customer in his white case C64C (long board, not a true C short board) and I fabricated and installed a sink for the VIC.

...I put up some info with photos on my website in the C64 directory under Lumafix.

http://personalpages.tds.net/%7Ercarlse ... 4/LUMAFIX/

[eslapion]

(Ray wants to spread the word on this.)

----------------------- Original Message -----------------------
Subject: LumaFix
From: Ray Carlsen
Date: Fri, July 6, 2018 1:23 pm
----------------------------------------------------------------

I noticed nothing about heat sinks was mentioned in the instructions for installation of a Lumafix module. Running a VIC chip with no sink will destroy it. Notice ALL C64's including the SX have a sink on the VIC. One guy said he installed a Lumafix, and his computer kept shutting down. The VIC was of course overheating after the original metal shield was removed. There are other IC's that need protection, and excessive heat will shorten their lives as well. A few weeks ago I installed Lumafix for a customer in his white case C64C (long board, not a true C short board) and I fabricated and installed a sink for the VIC.

...I put up some info with photos on my website in the C64 directory under Lumafix.

http://personalpages.tds.net/%7Ercarlse ... 4/LUMAFIX/

This is true of the 6567 (all revisions) and the 6569 (all revisions). The 8562 and 8565 used on boards 250469 do not use 12V and require no heat sink.

[groepaz]

not all C64s had a heatsink on the VICII either - there are even boards that dont have the metal cage at all.

(does he seriously advice to use epoxy to mount a heatsink? /o\)

[cbmeeks]

(does he seriously advice to use epoxy to mount a heatsink? /o\)

I wouldn't use epoxy for a heat sink. However, what do you recommend? I have normal thermal paste but that won't keep the heat sink from sliding off.

[groepaz]

there is special glue for that (no idea what the proper english term for it is)

[ral-clan]

There is thermally conductive epoxy that will transfer heat from chip to the heat sink. It's made for doing this sort of thing.

Here's a quick example I Googled, although I would not buy it at that price:
https://www.amazon.ca/Arctic-Alumina-Th ... B0009IQ1BU

https://www.overclockers.com/need-therm ... -your-own/

Cheaper:
https://www.ebay.ca/itm/Arctic-Silver-A ... SwXRxasutU

[groepaz]

yeah that kind of stuff. (however that textfile only says "epoxy" - which is a terrible idea)

[eslapion]

not all C64s had a heatsink on the VICII either - there are even boards that dont have the metal cage at all.

... in Europe ...

Prior to the C64c (board 250469 specifically), all C64 sold in Canada/U.S. either had a small metal shield around the VIC-II area or a large metal cover all over the entire board. Both were designed to touch the VIC-II to dissipate heat.

Using a 6567 without a heat sink results in the IC exceeding 60C very rapidly.

Some 6569 appear to be made using a different technology. I have a PAL 250425 with a 6569R3 dated 5185 and it dissipates about the same amount of heat as the 8565 used on the PAL 250469. It's a 12V VIC-II but only heats as much as the 5V one.

Obviously, Ray lives in the U.S. and rarely encounter European C64s.