Date   : Thu, 09 Nov 2006 11:47:44 -0000
From   : BBCMailingList@... (Ian Wolstenholme)
Subject: BBC Master AIV - Overheating

I've used my Domesday Master (Master 128 + Acorn
SCSI interface + 65C102 co-processor + VFS ROM rather
than "actual" Master AIV) for over 18 hours non-stop
doing copying from the Domesday discs without any
serious overheating.  I left it on overnight (what a sleepless
night that was!!) at one point but I took the lid off
to keep it a bit cooler.

The power supply got warm but my BBC Model B (Station 128)
gets a lot warmer in a shorter time.

If you haven't had the lid off then you might find it's the
terminator in the SCSI board that's generating the heat.  These
do get very hot in my experience, I think the combined wisdom
of the mailing list kind of agreed that this was probably 
"acceptable" if not normal for the Ohms, Amps, Volts etc.
associated with it.

If it's been badly handled in transit then it could be that either
the co-processor or the SCSI board have become loose.  I
would check this out before turning it on again.  I have put
detailed instructions on how to fit the SCSI board
correctly here:

http://www.beebmaster.co.uk/Domesday/Test1-0.html

Best wishes,



Ian

----- Original Message -----
From: Paul J [mailto:peterbilt@...]
To: bbc-micro@...
Sent: Thu, 9 Nov 2006 00:06:43 +0000
Subject: [BBC-Micro] BBC Master AIV - Overheating

Hi Group,

Having some problems with a master AIV with the 6502 co-pro card and SCSI
card fitted. I can't get the machine to boot, but the power light comes on
ok. One problem I found unpacking the machine is the moulded power plug was
cracked, and one of the pins bent. Looks like the machine was dropped
heavily on route, and landed on the plug bending the pin.

Having problems booting the machine, have left it switched on for about an
hour, and noticed the power supply seemed much hotter compared to a standard
master. The case near the power supply feels warm and touching the plate
near the power switch feels hot. Is this normal for a domesday master, have
heard about heating problems, but did not expect the power supply to feel so
hot.

Could it be something to do with bent pin on the power socket, in hindsight
I should not have plugged it in with that plug, but was eager to see if the
computer was ok. I paid a fair amount for the machine and really hacked off
Royal Mail have mishandled it, was sent special delivery too, having a bad
day.

Paul.