PET 6540 ROM operating temperature

[Josh Dersch]

On Wed, Nov 19, 2014 at 11:44 PM, John Kaur <digitgraph at gmail.com> wrote:

> My general rule, is if cannot hold your finger on for a count of five, you
> need fan directly on it (or sink, Robertson said), & experience has told
> me, that one-two years life!!
> John Kaur. in AZ where its hot>
>
> On Wed, Nov 19, 2014 at 10:39 PM, John Robertson <pinball at telus.net>
> wrote:
>
> > On 11/19/2014, 5:47 PM, Josh Dersch wrote:
> >
> >> Hey all --
> >>
> >> A quick one -- what's the normal operating temperature for the old
> MPS6540
> >> ROMs used in the original Commodore PETs?  I noticed last night after
> >> running mine for ~30 minutes that the ROMs were very hot, to the point
> of
> >> being painful to touch.
> >>
> >> The machine is running fine as far as I can tell -- though I haven't
> >> verified the contents of the ROMs, BASIC runs without any apparent
> issues.
> >> Voltages are normal (just a shade under 5V).
> >>
> >> I've not experienced ROM chips that run so very hot -- is this normal?
> >>
> >> Thanks,
> >> Josh
> >>
> >>  A fan is a good idea on older electronics. the cooler they run the
> > longer they last. A heat sink epoxied to the top of hot ceramic devices
> is
> > not bad either...
>


Oh, very much understood.  I don't really want to bandage over a problem,
though -- if these ROMs aren't *supposed* to be running hot then I'd like
to know so I can address the issue properly.  If this is normal behavior
then I'll probably do something to help reduce the heat and prolong the
(already limited) life of these 6540s.

Does anyone with direct experience with 6540s have any input here?

Thanks,
Josh



> >
> > John :-#)#
> >
> > --
> > John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
> > Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
> >                  www.flippers.com
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> >
> >
>