WHAT YOU SHOULD KNOW IF YOU NEED YOUR CBM HARDWARE REPAIRED latest updates or corrections 12-25-2021 * MY QUALIFICATIONS AS A REPAIR TECHNICIAN * REPAIR ESTIMATES & MY REPAIR PROCEDURES * A NEW REPLACEMENT POWER SUPPLY FOR YOUR C128 OR C64 * A RESET SWITCH FOR YOUR C64 (WARM AND COLD) * THE COMPUTER SAVER, A PROTECTION DEVICE FOR YOUR C64 * JIFFYDOS, A COMPUTER ENHANCEMENT AND DRIVE SPEEDUP CHIPSET * DRIVE SELECT SWITCHES AND WRITE PROTECT BYPASS MODIFICATION ************************************************************************* QUALIFICATIONS AS A REPAIR TECHNICIAN I've been a professional electronics repair tech all my adult life. I started back in the tube days fixing radios, TV's and many other consumer and industrial electronics devices. All of the shops are gone now because modern electronics is not considered repairable. I'm one of the few techs left that still service electronic equipment but my services are now limited to Commodore only. I began repairing Commodore gear and writing repair articles in 1986 when I bought my first C64 system. I joined several of the local Commodore clubs at that time. Since my retirement back in 2009, CBM 8 bit repair is all I do and it is more of a hobby than a business. I've collected lots of C= hardware over the years that I now use for parts. I don't routinely sell hardware or parts, just service, but I do make exceptions at times. The cause of a failure might seem like a particular bad component but could be something else. So, if I sell an IC in hopes it might fix the problem and it doesn't, I'm out that part (which are hard to get) and the customer has lost money. That's a lose-lose situation I try to avoid. I apparently have the only website dedicated to Commodore 8 bit hardware repair. If I can help you with simple problems, that's preferable to shipping it back and forth to have me do it. Email me at rcarlsen@tds.net and we can discuss the symptoms and possible solutions. Otherwise, I'll be happy to restore your hardware to factory condition. I also do upgrades and modifications. Before you send your equipment for repair, I suggest you read the instructions on my site regarding packing equipment for safe transport. I've seen too many items broken in transit due to improper packing or inadequate materials being used. I don't trust any shipper to pack goods properly... I do it myself! I use regular mail with tracking for most shipping unless requested to do otherwise. I add extra insurance if appropriate or if requested by the owner. Priority Mail costs more but packages don't always get there any quicker, and it doesn't offer any other benefits beyond $50 insurance unless you pay for extras. I rarely use UPS or FedEx for really expensive or one-of-a-kind items but I pack them myself and insure for more than they are worth to cover any possible loss or damage in transit, however unlikely. REPAIR ESTIMATES I can't know all the problems a computer or drive may have until I get it on the bench for tests, so exact estimates are impossible beforehand. Therefore, I usually "cap" repair charges for a C64, 1541, 1571, etc. at $50. Because the SX64 is much more complex as well as more compact and harder to work on, I would cap that computer repair at $100. Obviously the repair cost for both versions of the C128 will be more because it's much more complex and therefore harder to diagnose. Figure a cap at $100 for those as well. With this in mind, the repair for these devices could be less but will be no more unless agreed upon beforehand. I charge no more than what the repair calls for and I'll let you know the final cost so you can decide if it's worth it to you. To be honest, I essentially have to fix all the problems with a computer to find out all that's wrong with it. That said, if you decide it's not worth it, I stop there and you owe nothing because I don't charge for estimates alone. There are a few things that can push the cost higher. I check everything when I do a repair but I consider that a normal part of any work I do. You will not get your computer back with keys that don't work or some other fault even though the main problem is fixed. I've been on the receiving end of that kind of "service" before myself. Costs on any computer or disk drive would naturally go higher if special problems arise, if a drive has a bad head or I had to replace the computer SID (sound) chip, for example. Good SID chips are hard to find now and I've seen them priced at $35 and more. As of this writing, there is a substitute SID called the SwinSID Ultimate and another called the ARMSID. I have a small stock of these modules I can use for replacements during repairs to your computer. I charge only what those replacements cost me. Bad heads in a disk drive mean the mechanism must be swapped out since replacement heads are not available except from another drive. Another potential problem with the C64 is a computer severely damaged (many bad chips) by a failing power supply. Such damage makes that board uneconomical to repair, so I might just swap it out. Any device that has been tampered with by unqualified service persons may cost more to repair since I can't know what other problems may have been accidentally caused by such repair attempts. I used to insist the user send their power supply along with the computer, but there is still the risk that it will fail in the future and damage the computer. For that reason, if requested I can install my computer Saver circuit for a minimal charge in all C64's so they are safe with any PS from then on. Note that I also make an external Saver cable that plugs between the compter and PS. On all early version C64 boards, I also routinely install heat sinks on the chips that normally run hot to make them last longer. Regardless of what the hardware needs during repairs, I will keep you informed about anything that might push the cost higher. No "surprises". Of course upgrades like JiffyDOS and modifications like a reset switch would add to the cost but I'm not pushing any of that on you. My website describes all the mods I can do, but you decide what you want. Upgrades or mods would cost less if part of a repair job but not much more if that's all you want done. Before you send equipment for repair, let me know via email what the symptoms are and, if you're inclined, perhaps you can fix the equipment yourself. That's actually why my Commodore repair website was created. If the remedy is something simple such as cleaning the R/W head in a disk drive and the website doesn't tell you what you need, I'll be happy to talk you through it and perhaps save you the cost of shipping your hardware back and forth. REPLACEMENT POWER SUPPLY Since the original CBM power supplies for the C64 and "flat" C128 are dual voltage units and one source is 9 volts AC, there are few commercial off-the-shelf replacements made now. The world has moved on to +5VDC and +12VDC for electronic devices. A manufacturer would have to tool up for a limited market and that's not likely to happen. That's why I'm making a single universal replacement supply that can be used with any Commodore 64 or 128, even if they have a power hungry REU, RAMlink or carts connected. The 9VAC 1 Amp part of my PS is just a small transformer; nothing unique about that except that the one I use can easily be wired to work in Europe and Australia where the line voltage is 230 volts instead of 120 volts as in the USA and Canada. Because there are many different types of power plugs used in other parts of the world, I install an IEC socket on overseas power supplies. Then the user can obtain the appropriate AC cord locally that fits their mains. For the USA and Canada, I install a standard 3 wire power cord on my PS. The 5 volt source is a prefabricated "switching" type rather than the linear design used in the "bricks". It's either a 3 or 5 Amp capacity (depending on the PS model) with automatic short-circuit and over-voltage shutdown protection. A single power cable out of the PS case connects to a C64 and I can add a C128 plug to that cable in a Y configuration. If you buy a C64-only PS, a short adapter can be used to power the Plus/4 via a square 4 pin connector. A RESET SWITCH FOR THE C64: TWO TYPES, WARM AND COLD I can install a push button for a warm reset that will clear any BASIC program in memory and return the computer to its opening screen. However, a warm reset will not clear a ML program. The screen will freeze but you must turn the computer off and on again to completely clear it. As an alternative, I can install a simple cold reset circuit. It is implemented by use of a three-way center-off switch, normally placed on the lower left case side. Pushing the switch one way provides a warm reset and the other way a cold reset. The only drawback I've found to the cold reset is that an EPYX FastLoad cart may not work. All other carts I tried work fine and JiffyDOS is OK with it. Which reset modification you choose will depend on how you normally use your C64. For example, if you use a freezer or other cart with reset already on it, you will not need that mod. If your usage requires many off/on cycles, a reset switch is handy and saves wear and tear on the power switch. THE COMPUTER SAVER: A PROTECTION DEVICE FOR THE C64 A failing power supply such as the original Commodore black or white "brick" can do a lot of damage to a computer, making it uneconomical to repair. I hand-make small batches of what I call the Saver in three different versions. A Saver module can be installed in any C64, Plus/4 or late version VIC20CR to protect those computers from PS damage. That mod is normally done during repairs but could be installed at any time. Shipping back and forth for that upgrade alone would cost more than the mod itself but I can install it during any repair job. I also sell a completed module that the user can install in their own computer. Lastly, I make two external versions that plug between the computer and its PS. I don't have a regular sales outlet or use Ebay. I'm a repair tech (now Commodore-only after retirement) and now do this mostly as a hobby. JIFFYDOS: A COMPUTER ENHANCEMENT AND DRIVE SPEED UPGRADE JiffyDOS is a chipset that, when installed in a C64 or 128 (VIC20 and other versions also available) allows many one-button commands such as: press F1 for a disk directory listing and F5 to load a ML program. An additional JD chip in a CBM disk drive will allow faster access. I can install JiffyDOS in your computer and/or drive in one of two ways. You can buy the chipset modules for your devices and send them to me with the hardware for installation or, with Commodore hardware only in hand, I can program and install chips myself after I buy the codes from an authorized source such as Jim Brain. The final cost for you is about the same but if I program chips and install them, turnaround time is less. I also make switchless JiffyDOS modules that don't require holes drilled in the computer case. Such a computer boots in Jd unless a button is held down during power up or reset. DRIVE SELECT SWITCH INSTALLATION AND WRITE PROTECT BYPASS WITH SWITCH From the factory, a drive such as the 1541 is hardware wired as device 8. I can install a switch on your 1541 or equivalent disk drive or C128DCR to enable you to easily change the device number of the drive. Note that the 1541-II, 1571 and 1581 disk drives already have device select switches on them. With an added switch, the 1541 or DCR drive can be changed 8/9 or 8/9/11 with a multiple position toggle switch. A four position slide switch (or two toggle switches) can be installed to select any device number from 8 through 11. A switch and simple circuit installation in a disk drive will enable you to write to write-protected disks without notching them first or removing the WP tab. A switch on the front of the drive is recommended so that you can easily see the WP status (normal or bypassed) and not accidentally overwrite a valuable disk. Ray