senderow@janus.Berkeley.EDU (Dan Senderowicz) (08/29/90)
My old kaypro II just died of old age. The cpu board works but there is no video. The crt gun is cold, indicating probably that the tube is bad (filament) or something is wrong with the power supply (maybe the transformer). I would really appreciate it if anybody has the service manuals to lend thme to me so I can get a better insight of the hardware. I called Kaypro but they don't longer have anything for that machine. Thanks. Dan.
callisto@blake.acs.washington.edu (Finn) (08/29/90)
In article <38499@ucbvax.BERKELEY.EDU> synchrods!daniel@janus.Berkeley.EDU (Dan Senderowicz) writes: >My old kaypro II just died of old age. The cpu board works but >there is no video. The crt gun is cold, indicating probably that >the tube is bad (filament) or something is wrong with the power >supply (maybe the transformer). I would really appreciate it if >anybody has the service manuals to lend thme to me so I can get >a better insight of the hardware. I called Kaypro but they don't >longer have anything for that machine. Thanks. You are in luck! The Kaypro machines are totally generic.. meaning they used the standard stuff of the era (except for the keyboard) and much like disk drives and PC power supplies are today, you can plug in almost anything and have it work. Specificly, the Kaypro used the Ball monitor. Not that they bought the monitors from Ball, but bought whatever was cheapest that week. You want to look closely at the card edge plug on the monitor in your machine.. you'll see there are 10 contact points and a slot cut near one end. Your local computer parts supply and junque dealer may not still know what a Ball monitor is, but if it has that same connector, it's going to work 99 times out of a hundred. Now the only trick is finding one the right size for your case.. although I have built Frankenkaypros fom junk parts and used everything from ultra small cash machine style monitors to huge 16 inch monitors. Last I bought one of these things ( a couple of years ago) the going rate was $25 for a used or grungy but workable monitor, about $40 for new surplus stuff and real nice ones maybe as high as $65. The above is an assumption that your monitor has packed it in.. the power supply is a simple 5 and 12 volt switching supply and it is pretty unlikely that it would keep the motherboard and drives happy and fail to deliver the 12 volts to the monitor only. Just to be safe, before spending any money on the monitor, make sure you have +12 on pin 7 on the monitor connector. (The connector may not be numbered, but the notch is between 9 and 10) If you are interested the connector on the monitor is as follows: 1 Ground 2 3 4 Brightness pot on 2 & 3 with wiper to 4 5 Arc Gnd (often not used) 6 Horz. Sync. 7 + 12 8 Video 9 Vert. Sync. Notch 10 Ground If your power supply is NOT making 5 and 12 volts, then it will also run you $30 - $40 if you shop around. You can use almost any reasonably rated switching power supply that will fit into the case. You may or may not have to re-do the power supply connector. Usually the outputs on power supplies are well labled. It is important to get the same voltages into the same wires. Check everything twice, then have someone else check it for you. (I once toasted 2 drives at once by sending 12 volts down a wire that turned out to want 5 volts.)
mike@DRD.Com (Mike Rovak) (08/30/90)
synchrods!daniel@janus.Berkeley.EDU (Dan Senderowicz) wrote: } My old kaypro II just died of old age. The cpu board works but } there is no video. The crt gun is cold, indicating probably that } the tube is bad (filament) or something is wrong with the power } supply (maybe the transformer)... I just recently unloaded a II here in Tulsa. Fortunately for me, my video died earlier, and my local Kaypro dealer replaced the video board and the tube. My understanding of the kaypro II video is that there are several types of tubes in II's, each requiring a matching video board. Therefore, the first thing I would do would be to try to find an exact replacement tube from an electronics parts place, assuming that a voltmeter says that your filament voltage and high voltage are still intact. If this fails, there is an outfit which advertised in the Kaypro mags called ERAC which carried spare parts, especially video. Sorry, I don't have any further information about them, except to say that you might try calling Microsphere in Oregon to get additional hardware type help or phone numbers. --Mike ------------------------------------------------------------------------ Disclaimer: My opinions do not necessarily reflect those of my employer. ======================================================================== ------------------------------------------------------------------------ mike@DRD.Com uunet!apctrc!drd!mike ========================================================================
gary@cdthq (gary) (09/02/90)
mike@DRD.Com (Mike Rovak) writes: > synchrods!daniel@janus.Berkeley.EDU (Dan Senderowicz) wrote: > } My old kaypro II just died of old age. The cpu board works but > first thing I would do would be to try to find an exact replacement tube > from an electronics parts place, assuming that a voltmeter says that your > filament voltage and high voltage are still intact. Note that measuring the high voltage on a tube requires a special HV meter. You're trying to test something in the area of 8-9KV here, at very low current levels. Do NOT try to measure it with your average VOM; it's not designed for it. FYI, a color tubes' HV is generally 20KV or higher. Don't poke around with it unless you have the proper tools and someone standing by to shut off power in emergencies. Gary Heston, at home....