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Re: Downright Criminal RAM
- Subject: Re: Downright Criminal RAM
- From: heuser.marcus@freenet.de
- Date: Sat, 08 Sep 2007 07:41:12 -0700
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On Sep 8, 11:20 am, Tristan Mumford <xtristan.xmumf...@xgmail.xcom>
wrote:
>
> Besides that the power supply was reading erratic voltages.
> Most notably on -5 and -12v.
>
> The 4116 RAMs use just about every voltage rail available. Both
> positive an negative. Apart from possibly -12v. To be honest I
> couldn't be bothered checking.
According to the Mostek datasheet the 4116 indeed uses +5V,
-5V and +12V. The datasheet also says that the chip accepts
tolerances of +/- 10%.
> One day during a poweron, or powercycle or something one
> of the 4116 RAMs developed an internal short. They are quite
> old after all.
Sounds possible.
> The shorting of the 4116 caused the internal potential of the other 4116
> RAMs to change because of the clobbering / positive energising of the
> negative rails (or it just shorted out into the address / databus). The
> shift in voltages caused more to fail and so on.
Maybe. Did you try to pinpoint the damages chips?
bye
Marcus