Replace the old leaky capacitors before (or after) they damage your precious vintage Macintosh motherboard. I'm am selling sets of new capacitors for reworking old Mac logic boards.
Tantalum capacitors will not leak corrosive goo onto the motherboard the way that conventional surface mount electrolytic caps do when they get old. Most of the caps I offer have slightly higher voltage ratings than the original caps. This does not affect operation and may yield a longer life time. Cost & Payment & Contact info: ============================== A set of fifteen (your choice of values) capacitors is $10 shipped in the USA. Additional capacitors beyond the first fifteen are $.50 each and do not add to the shipping cost. Folks outside the USA see the international instructions below. If you need more than fifteen, see the discussion below. My PayPal ID is quar...@prismnet.com. My email address is t...@prismnet.com. I also accept mailed payments. Choice of Capacitors: ============================== Different Models of Mac (and sometimes different Macs within the same model) contain different assortments of capacitors to replace. The best thing to do is to look in your Mac and count what you need. I offer the following capacitors and they encompass most of the capacitors found on vintage Mac logic boards: Surface Mount: ==================== 47 uF 16V AVX TAJD476K016R Size D 1 uF 35V KEMET T491B105M035 Size B 10 uF 20V AVX TAJB106M020RNJ Size B 100 uF 10V Vishay 293D107X9010D2T Size D Axial (with leads coming out the ends): ==================== 220 uF 35V Axial Electrolytic Capacitor 470 uF 16V, 105C Axial Electrolytic Capacitor (approx. 3/4" long X 3/8" diameter) 470 uF 50V, 105C Axial Electrolytic Capacitor (approx. 1" long X 1/2" diameter) Rectifiers ==================== MR824 400V, 5A, Fast Recovery (For Mac Plus Analog board. I happen to have a bunch of these.) Battery Holder ==================== 1/2AA Battery Holder $2.50 w/ capacitor order SE/30: ============== Every SE/30 for which we have a report has contained ten 47uF surface mount electrolytic capacitors, one 1uF surface mount electrolytic capacitor, and one each of the 220uF and 470uF axial capacitors. That's only thirteen, so a set of fifteen gets you a couple of extras. IIci: ============== The IIci contains either eight or eleven 47uF (you'll have to open it and count them) and two 10uF surface mount electrolytic capacitors and three 470uF and one 220uF axial electrolytic capacitors. If you have the model with eleven 47uF caps, that's actually seventeen total, so for a complete IIci set you would need to add two additional capacitors to the $10 set of 15 for a total of $11.00 for 17. Additional Caps: ==================== Additional capacitors beyond the first fifteen are $.50 and do not add to the shipping cost. If you need two sets, do not double the $10 per set cost, just add additional caps at $.50. So, for example, if you want 30 capacitors total, your cost is $10 for the first fifteen plus 15 X .50 = $7.50, for a total of $17.50 per 30. International Purchases: ==================== If you're outside the USA the cost will be $10 plus postage to your location by 1st Class international, which will usually be under $3, i.e. < $13 total. Helpful Instructions soldering instructions: ============================== You can find way more discussion and helpful suggestions in the forums at 68kmla.net. There are several ways of doing each of the steps below, but here are the methods I usually use: 1) Remove the old capacitors. In my experience, the easiest way to remove the old surface mount caps is to use two soldering pencils at one time. Be patient. Do not apply much force lifting the cap, nor attempt to pry it up. Using a pair of 15 watt pencils, removing a cap may take more than a minute. A pair of 25 watt pencils is probably a better choice, but Radio Shack sells a 15 watt grounded pencil for under $10. Be patient. Impatience lifts pads. The axial caps can be removed by snipping the leads and then desoldering the leads one at a time. Again, be patient. Do not attempt to pull out a lead which is still resisting. Applying a little liquid solder flux to the pads and holes may make desoldering easier. 2) Remove old solder from the pads (surface mount) and holes (axial). Desoldering braid works fine for this. The braid will work much more easily if you apply some liquid soldering flux to the solder to be removed. For stubborn axial holes, I sometimes heat one side with a pencil and insert a sewing pin from the other side. This pushes the molten solder out of the hole on the pencil side. After it cools it can be snipped off and the remainder cleaned up with braid. When you're done removing old solder the surface mount pads should be flat. The axial holes should be open. 3) Clean the board. You may use spray flux remover, or isopropyl alcohol (no additives such as colors or skin softeners) or even detergent and water. Some folks put the board in the dishwasher without detergent. You may wish to use an old toothbrush to remove stubborn deposits. 4) Rinse the board with distilled water and let dry. This gets rid of residue of whatever you used to clean the board. 5) Install new capacitors. Note that tantalum surface mount caps have a stripe on the positive terminal. The old electrolytic caps which you removed have a stripe on the negative terminal. See the helpful diagram at the bottom of this page: <http://home.earthlink.net/~gamba2/se30repair.html> Axial caps are easy. Insert the leads in the holes and then solder them to the pads. For the surface mount (SM) caps, tin (apply a little solder to) one pad and leave the other pad clean. Place a cap onto the pads with tweezers and hold it down with the blade of a small flat screwdriver or similar. While pressing the cap down with one had, solder the tinned pad with the other hand using a soldering pencil. After the cap sinks down to the pad through the molten solder, remove the pencil, wait a few seconds and then remove the screwdriver. The caps is now attached by one pad. Solder the other pad normally. Do not tin both pads. If you do so, the cap will not be able to sink down to the pad, as the cold hard solder on one side will keep the cap from bending down to the pad on the other side. Jeff Walther 8107 Hillrise Dr. Austin, TX 78759 t...@prismnet.com -- You received this message because you are a member of the LEM Swap group. To post to this group, send email to lemswap@googlegroups.com To unsubscribe, send an email *from your subscribed address* to lemswap+unsubscr...@googlegroups.com LEM-Swap is not a discussion list; it is for buying & selling Mac stuff. Reply directly to the person who posted, never to the list. Software piracy is illegal and not allowed on LEM Swap. Except for freeware and software originally provided with computers, no software is to be left on hard drives unless the original installer (not a burned copy) is included, along with any required registration number, password, etc. Shipments valued at US$100 or more should be insured, and shipments valued at US$25 or more should be shipped so they can be tracked. See the list FAQ http://lowendmac.com/lists/swap.html for guidelines on postings, feedback, and dispute resolution. Seller feedback at http://groups.google.com/group/swap-feedback
