C64 Repair Help

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Zippy Zapp
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Re: C64 Repair Help

Post by Zippy Zapp »

I just picked up one of these:



I used it last night on a C64 board that I had previously removed 2 RAM chips from with a combination of tools including my Hakko solder station, radio shack de-solder iron, solder wick and solder sucker. While the first one went ok with this method it took a long time and was far from easy.

I used the station linked above and had the remaining 6 RAM chips out in less then 10 minutes with no damage to the RAM pins or the motherboard. The station was set to 275C and 310C for the ground pins and it was easy. I couldn't believe what I had been missing! Sometimes it is about the right tools!

My first SMD work was last week on an ISA Ensoniq sound card that needed 22 SMD caps removed and replaced. I managed to remove them with hot air but broke off 1 pad and lifted another. I did my best to repair the destroyed one by using a resistor lead piece and soldering it to the cap and a nearby via that connected to the pad. All caps back in and I am going to test it this weekend. If I borfed it, thats ok as it was free and was more for practice before I have to do the process on an Amiga 1200. I found that challenging as I don't really know if I had the temp right and all that. Some of them I could tell melted when I lifted them off some didn't...


Commodore - Changing the world 8 bits at a time.
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eslapion
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Re: C64 Repair Help

Post by eslapion »

Zippy Zapp wrote:... I couldn't believe what I had been missing! Sometimes it is about the right tools!
Its always like that.

I can't count how many times some noob on "you know where" told me that I wasted my money buying an Hakko 808 or a 1k$ programmer (BK Precision 866B back in 2008), solder fumes remover and lab power supply. They always seem to have a better 2.5 cents solution that's sooo much better but they always ruin the stuff they have in front of them.

Guess why...
Wealth, like happiness, is never attained directly. It comes as a by-product of providing a useful service. -Harland D. Sanders
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motrucker
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Re: C64 Repair Help

Post by motrucker »

eslapion wrote:@motrucker
I have a more expensive solution because I do a lot of desoldering and there are many good yet inexpensive solutions out there; A hot air gun is NOT among them unless it is equipped with an accurate temperature control system which ensures you reach an adequate temperature for soldering/desoldering without causing damage to the circuit board and components.

Using hot air is fantastic with surface mounted components, not so with through-hole components which may have mechanical hold on the PCB which encourages the technician to overheat the board until the component drops-off even when held in place by something other than solder.
I am "just" an electronics hobbyist. My main line of work was/is an Antique Restoration Tech, or conservator specializing in Furniture, and keyboard instruments. I studied electronics at NRI Just after I got my first real computer back in the late '70s. So, I still don't need such sophisticated equipment. I do buy equipment when I see a really good deal, like the soldering station I bought about a year back. I am extremely glad that I studied Electronics, so I know what I am looking at when I open a computer, and understand at least the basics of the circuits. Every hobbyist should learn at least that much, rather than just thinking they know what's what.
C-64, C-128, and Amiga A2000 user
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eslapion
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Re: C64 Repair Help

Post by eslapion »

motrucker wrote:I am "just" an electronics hobbyist
Yeah but apparently you "just" have in excess of 40 years experience... so I guess like Ray Carlsen you must "just" be a walking encyclopedia of tricks, tips and various gems of accumulated knowledge... 8-)

I have to admit I am in need of better tools than most because I may have a good ability for details but I have relatively poor manual dexterity. I have to compensate somehow.

A tech with good experience and manual ability may not require what I need.

Trouble brews when ordinary unexperimented people try to use your tricks without first trying on stuff they can sacrifice and without supervision.
Wealth, like happiness, is never attained directly. It comes as a by-product of providing a useful service. -Harland D. Sanders
JaseSerre
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Re: C64 Repair Help

Post by JaseSerre »

Hi...i am a new user here. As per my knowledge Overheating any epoxy/fiberglass circuit board will cause carbonisation of the epoxy and render it semiconductive, just like a resistor. So now, all around your PLA are resistors causing small amounts of current to flow between all communication lines of the PLA socket.If that's what happened then your board is effectively permanently damaged. This is the sort of thimng that will cause all sorts of random erratic behavior and data corruptions.
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eslapion
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Re: C64 Repair Help

Post by eslapion »

JaseSerre wrote: Tue Jan 24, 2017 4:58 pmHi...i am a new user here. As per my knowledge Overheating any epoxy/fiberglass circuit board will cause carbonisation of the epoxy and render it semiconductive, just like a resistor. So now, all around your PLA are resistors causing small amounts of current to flow between all communication lines of the PLA socket.If that's what happened then your board is effectively permanently damaged. This is the sort of thimng that will cause all sorts of random erratic behavior and data corruptions.
You got it!
Wealth, like happiness, is never attained directly. It comes as a by-product of providing a useful service. -Harland D. Sanders
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