C64 Restore and Repair

The venerable Commodore C64 is my favorite thing to repair and restore. It happens but I rarely find one that I can't get going again. 

There are many ways to go about Commodore 64 including modern emulators. My interest is restoring C64s with as many original components as possible. 

I will not sale a known non-working model and I go through a lot of testing to ensure the product is up to specifications and that the product description is accurate. 

I always include authentic VICii, SID, CPU, ROM, RAM, and CIA chips in the products I restore. I may option to use an FPGA PLA chip as those are very fragile and I have not had an issue with comparative performance in place of those. All the products I product on my site will clearly indicate what main chips are on the board.

 

I live in the USA so most boards are NTSC instead of PAL and I will ensure the board and chips match for the correct output. I will also list in the product page the case and board specifications. Most of my projects are C64 breadbin with 250407 boards as they tend to be the most easily sourced. 

I don't have anything against FPGA chips and use them in my modern board designs (c64 reloaded and sixty clones). There are some advantage of FPGA chips including less heat and power draw and maybe more life. However, I feel like most people wanting a vintage C64 likely want the original chips (especially the SID chip). It is rare that I have matching serial numbers, chip dates, or cases but that is something that does not bother me much. 

If all this C64 chip discussion is overwhelming do not worry about it, just know I will select the right chips for the board and ensure it works. 

My more than 40-point diagnostic and repair process: 

1. Case and board clean up including ports and switch.

2. Case stand offs and clip inspection and repair if required.

3. Voltage check on the main regulators and at important chips, user port, and rail locations.

4. Oscilloscope check of clock frequencies on VIC and PLA chips and other points if required.

5. Timer circuit and logic chip test.

6. Reset signal check on PLA chip.

7. Dead test (black screen) if not working.

8. Full diagnostic and SID sound test.

9. Repair or replacement of faulty components.

10. Add heat sinks to components that typically get hot.

11. Keyboard test

12. Cartridge and serial port test

13. BASIC startup test.

I do not typically recap the entire board as I have not found that to be required and try to keep as much as possible original. However, some boards may require it and will be indicated as such in the product page. 

Pricing Transparency

Repairing electronic devices requires a significant investment in knowledge and equipment such as multimeters, soldering skills, desoldering skills, sockets, components, oscilloscopes, function generators, and patience. My investment in this activity started with amateur radio electronics and later in other products such as cameras and retro computers. My goal is to use my knowledge and equipment investments to help others attain these great retro products.

Power Supplies

Please never use the original C64 PSUs with these unless you also have a power saver. If you do not have a modern PSU I will provide links to some options. The original C64 power supplies were known to fail 40 years ago and are prone to failing on the DC side with high DC current. The C64 uses a 9 volt AC and 5 volt DC source. Once in the board the 9VAC is regulated to 12vDC and 5vDC for the video and audio section and the original 5vDC goes to the other chips. They are very sensitive and a PSU failing above 5.4 volts can permanently damage them. I try to keep a few new modern power supplies as well and when I will list the product with and without the power supply. I have had good success with the Electroware C64 and Keelog C64 power supplies but the best in my opinion is the custom power supplies by Ray Carlson. 

And of course, these are 40 plus years old now and can stop working after I test them. I will test the C64 prior to shipping and if it arrives not working contact me immediately for troubleshooting and I will gladly accept returns for full refund within 30 days as long as the unit is in the same condition and has not been used with an improper or original power supply. 

AV Cables and Connectors (How do I connect this to a video source?)

You will need a monitor or TV with component video in (the yellow, red, and white RCA jacks) or S-video input and an S-video cable. You will need an AV or S video to HDMI upscaler or use the composite (yellow, red, white inputs) work fine and many TVs still have them.

The C64 also has an RF out but honestly you will have a harder time finding a TV with an RF input and they are a pain now that most new TVs are digital, not to mention the RF input isn't as good. 

My advice is to purchase a very affordable 14-to-20-inch TV from Amazon or your local box store that has composite video inputs.

Ok, I am in I really want an original C64 but I have no software or floppy drive what can I do?

Glad you asked and I will provide more details on this on the site but there are many options for interface devices for the C64. Honestly this is why the C64 did as well as it did in the 1980s. Unlike the Atari or some other devices, the C64 has multiple input output ports including its well-known cartridge port, tape port, user port, and serial port. Today these have been exploited further to accept interfaces such as SD and USB memory devices and more.

Many of the 8-bit games and software are available online for free or a very small price for use. You simply download them put them on the memory device (like a USB drive that you can put thousands of 8-bit software on) and then use a device that emulates the original floppy or tape drive.

While it is a more expensive option my recommendation is the Ultimate II. It emulates the cartridges as well as tape and floppy drives all in one and you can even get on Bulletin Boards over the internet with it. But, if you have an original floppy drive or tape drive that is working...you can use that too...which is very cool; slow, but cool. And let's face it, you are doing this for the nostalgia but also the cool factor. 

AND there are still new games being produced ONLY for the C64. One recent example that is very popular that I like is the game "A Pigs Quest" 

Do I have to learn more about using the C64 if I have never used one?

Yep! But this is the whole point of most people's interest in retro computing to learn and enjoy the era that ushered in our current knowledge of computing. 

Flaskback!!!!!>>>>>> (that is why this site is called Flashback Fix, imagine some awesome theme music playing now and some really impressive graphics of you being sucked into a time space worm hole to 1980)

In the mid 1970s most average people had only heard of computers. In fact, 1972 was the first year that color TVs outsold black and white televisions. In 1982 the C64 was not the first home computer but it was the first where the capabilities, cost, and distribution in retail stores made it the most sold personal CPU of all time. 

However, this was long before plug and play and graphical user interfaces (think Windows), (however there is some very interesting history between Microsoft (Bill Gates and the original C64 BASIC and the evolution of computer software we know today). Do a YouTube search for the Altair 8800 if you are interested in how all this got started around the 6502 chip that was the precursor to the 6510 CPU chip for the C64. Most all of the early computers and gaming systems such as Atari and Commodore were the result of the innovation associated with this chip set. 

Early home computers demanded more intelligence of the user to interact with the computer. Assembly language had not evolved so you had to remember some code and commands to interact with the C64. But it's not hard, and the internet is plentiful with information. For example, when you load a floppy on a C64 you can't just insert it and it start running. You use a command such as:

LOAD "*" ,8, 1

...where 8 is the address of the drive and 1 is the address of the first program on the drive. It takes some getting used to but imagine how impressed your friends will be and how much more intelligent you will be compared to them!

Cartridges are easier, just plug them in and power on the C64.

Repairs

Have a C64 that is not working? I may be able to help. Message me and if you live in the U.S,A  I can work with you on getting it to me for diagnostics and I can give you a quote on the repair before repairs are initiated. If I can't fix it, you just pay the shipping both ways. Do not send the product to me before contacting me to ensure my availability and when contacting me please include as much information as possible about what the machine is doing (or not doing). 

 

Disclaimer: For informational purposes only. Other vendors' products or services referenced are for informational purposes only. Flashback Fix does not formally endorse, warrant, or have a financial or marketing interest in them.