Re: My Lisa 2 got a defect Monitor

From: James MacPhail <uo957_at_email.domain.hidden>
Date: Mon, 8 Oct 2001 13:19:04 -0700

>i have no idea what you're talking about! Explain in plain english
>please. i know almost nothing about them and i just got them!!

Thomas made a very good attempt to translate into English, however if you are not familiar with the subject, it can be hard to interpret.

Thomas wrote:
>>I got a similar fault with one of my Lisas. The monitor kept being totaly
>>death, although the tube was fired with the whole low voltage, but not the
>>high-voltage from the HV-transformator at the left side under the tube, when
>>looking from top of it. Answer my question: does your HV-transformator
>>whistle or not? If not, it's probably dead like mine. You can plug it of
>>(the fat HV-cable to the tube and the 6 wire plug to the monitor board) and
>>change it (from another Lisa, perhaps) and try. In my case it works again
>>and since that time I'm looking for some parts to replace

Here is an attempt at a translation... probably still hard to understand.

"I had a similar problem with one of my Lisas. The monitor was dead. The tube was receiving low voltage power (so the filament would light up), but no high voltage from the flyback transformer (under the tube on the base of the chassis). Does your high voltage transformer whistle? If not, it is probably dead. You can unplug it (the fat HV cable to the tube and the 6 wire plug to the video board) and replace it. In my case, this solved the problem, so now I'm looking for spare parts."

My comments...

  1. Messing with the High Voltage can be lethal and deadly or even kill you, even with the line cord disconnected! If you are not familiar with working on TVs or Monitors, you should get someone who is experienced to help. If you are in a remote area and help is not available, ask for specific safety instructions.
  2. The whining of the flyback transformer is created by the switching current from the video board. No whining may mean the video board is defective or not receiving the correct power and signals, so I think that a bad flyback transformer is not the only cause of this symptom.
  3. In Alex's case, it seems unlikely that the flyback would be damaged by connecting an external monitor, however it may be a coincidence that it failed at that time, so the flyback may be bad anyway.

HTH, James

James MacPhail                   "Think not of engineering as art,
uo957_at_email.domain.hidden                 but of art as engineering"
Sigma Seven Systems Ltd.
james_at_email.domain.hidden        <>

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Received on 2001-10-08 13:29:45

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