powertowerpro225

In principle, there are three things that can affect the behaviour of a computer after storage: battery, oxide/corrosion and electrolytic capacitors. You have changed the battery. Boards and memory modules have been cleaned. Have all cable connectors been disconnected and reconnected? You may want to inspect all boards with a magnifying glass; look for corroded areas and signs of leaking/bulging/discoloured/cracked electronic components.

Have you tried to remove/disconnect all parts/devices not immediately required? That could be the hard drive, the floppy drive or the CD-ROM drive (depending on boot method), anything but basic RAM, and all not essential PCI cards.

Are the 5 V and 12 V DC voltage levels OK?

Regarding the startup sound, does hard drive activity indicate that the computer is fully starting up? If yes, has the speaker itself or a headphone jack (switch/contact) been checked?

In your original post under Desktop Computers/Power Mac, you mentioned that two computers have the same "no video" problem. If so, is there possibly some kind of external common denominator (power, keyboard, monitor, etc)?

Jan

helmut,

Your original post of 28 Feb on this subject is in the PowerMac forums here:

hi i have a powertowerpro 225 built in1996 its been in storage for 12 yrs was working fine then it boots up but no im…

and has some responses. No need to start a new thread.

Helmut,

>and 14 in screen with a 15 pin connector but it only has 10 pins is that a problem ??

It may or may not be a problem. Is it a VGA (three rows) or Mac (two rows) plug? If you study pinouts (try a web search for something like "VGA pinout" and "Mac monitor pinout"), you will notice that not all pins are used/needed. For a VGA plug, it is not unusual to see at least one pin missing. Without knowing exactly how/if the pins in your monitor plug are connected, it is not possible to say whether the arrangement is OK or not. Could you perhaps test the monitor with another computer?

Now when you get the startup sound, you may want to try a PRAM reset a couple of times as well.

>I don't know how 2 ck the voltage

You would need a multimeter to check the 5 V DC and 12 V DC. The multimeter must be set to an appropriate V DC range. 5 V DC and 12 V DC can be found at various places in a computer (on boards or in low-voltage cable connectors). If in any doubt about how to do this, please ask someone with the necessary knowledge to help you. Do not open the power supply unit! Do not carry out any high-voltage (AC) measurements! Do not open the monitor!

Jan

Hello again,

Do not expect too much from a visit to a computer store. The staff may not be familiar with these older machines.

What about testing a plain old (PC-style VGA) CRT monitor (not a modern flat-screen model) connected to the PowerTower 225 VGA port (15 pins in three rows)?

With the computer turned off, try once again to disconnect and reconnect all internal cards/modules and cable connectors. To begin with, do not reconnect anything that is not absolutely required (such as extra RAM). Also, study the boards with a magnifying glass again (there may be leaking/bulging electrolytic capacitors, or other faulty components, that are not easy to detect).

Under your other topic, you mentioned a Power Macintosh 7200. Did you try to just replace the hard drive in the Power Macintosh 7200 with the one from the PowerTower Pro 225? If necessary (if the 7200 would not start up from the new internal hard drive), do you not have access to any other startup disc (CD) or disk (such as a Disk Tools floppy)?

https://discussions.apple.com/thread/6853290?start=15&tstart=0

Does your Mac monitor work when connected to the 7200?

Jan

As far as I know, a Starmax 3000/200 has an IDE/ATA internal hard drive (even though SCSI would be available, at least for the external port). A PowerTower Pro 225 (and a Power Macintosh 7200) would have an internal SCSI hard drive.