ash@hpindda.cup.hp.com (Art Harkin) (06/25/91)
My MacPlus (upgraded from a Mac 512K) seems to be having power supply problems. My screen brightness controller has to be set to its lowest setting to make the screen be at its correct brightness (otherwise, its too bright). Also, I was having modem problems (one of them my have burned out) and it may because of too high of a voltage being sent over the RS232? The modems work okay with another Mac. I tried to get readings off the power supply to see if its providing to much 5V or 12V, but it didn't seem so. But, I do not have a schematic or checkpoints to totally verify this. Is this a common problem in older macs? Is it fixable, the voltage adjustment knob did not seem to help too much. Is it possible to get an analog board for a Mac Plus at a reasonable cost anywhere (in south SF bay area)? Thanks in advance, (replying by email will be fine) Art Harkin ash@cup.hp.com
raoul@seattleu.edu (06/26/91)
ash@hpindda.cup.hp.com (Art Harkin) writes: > > My MacPlus (upgraded from a Mac 512K) seems to be having > power supply problems. My screen brightness controller has to > be set to its lowest setting to make the screen be at its > correct brightness (otherwise, its too bright). > Also, I was having modem problems (one of them my have burned > out) and it may because of too high of a voltage being sent > over the RS232? The modems work okay with another Mac. > > I tried to get readings off the power supply to see if > its providing to much 5V or 12V, but it didn't seem so. > But, I do not have a schematic or checkpoints to totally > verify this. > > Is this a common problem in older macs? > Is it fixable, the voltage adjustment knob did not seem > to help too much. > > Is it possible to get an analog board for a Mac Plus > at a reasonable cost anywhere (in south SF bay area)? > > Thanks in advance, (replying by email will be fine) > > Art Harkin > > ash@cup.hp.com This is ery common to early Macs. Get a new analog board/pwr supply and the problems will be gone. No cheaper way that I know. Jeff. -- The 23:00 News and Mail Service - +1 206 292 9048 - Seattle, WA USA PEP, V.32, V.42 +++ A Waffle Iron, Model 1.64 +++
cramer@Eng.Sun.COM (Sam Cramer) (06/27/91)
>>>>> On 26 Jun 91 01:51:59 GMT, halcyon!raoul@seattleu.edu said: ash@hpindda.cup.hp.com (Art Harkin) writes: ash> My MacPlus (upgraded from a Mac 512K) seems to be having ash> power supply problems..... ash> Is this a common problem in older macs? ash> Is it fixable, the voltage adjustment knob did not seem ash> to help too much. raoul> This is ery common to early Macs. Get a new analog board/pwr supply raoul> and the problems will be gone. No cheaper way that I know. These boards can be fairly easily repaired. You almost certainly do *not* need a new analog board, unless something has gone horribly wrong. For those who know how to use a soldering iron, Larry Pina's book entitled "Macintosh Repair and Upgrade Secrets" will tell you how to do it. Otherwise, there are places which do component level repair of the analog board; check with your local Mac users group, or take a look in the back of MacWorld/User/Week. One place that is often recommended is Soft Solutions, which can be reached at (503) 461-1136. Sam