Path: utzoo!attcan!uunet!seismo!dimacs.rutgers.edu!aramis.rutgers.edu!paul.rutgers.edu!njin!spcvxb.spc.edu!terry
From: terry@spcvxb.spc.edu (Terry Kennedy, Operations Mgr)
Newsgroups: comp.sys.dec
Subject: Re: More MVII Hardware Help
Message-ID: <1990Oct9.195516.598@spcvxb.spc.edu>
Date: 9 Oct 90 19:55:16 GMT
References: <8810@pitt.UUCP>
Organization: St. Peter's College, US
Lines: 26

In article <8810@pitt.UUCP>, jcd@pitt.UUCP (Jim Durham) writes:
> Second...if
> the MVII is dusty, check the voltage on the bus. The connectors from
> the power supply to the bus are cheesy and you can get over a volt
> of drop in the +5 supply. TTL doesn't work well on 4 volts. I've
> been through this one, too. If you have an extender card, pull
> some module, put it on the extender, and measure with a digital
> voltmeter from ground to +5 on some chip. If you don't have
> at least 4.9 volts, better clean up the power suppply/bus connectors.
> I hope this helps someone to not lose as much cranial hair as I did.

  If you're getting 4V there, it isn't dust 8-(.

  Seriously, if you have a BA23 master box (with front panel halt and restart
buttons), you should have the power harness checked. The old harness can catch
on fire. The way to tell if you have the proper harness is to open the BA23
up and look in the drive bays. The good harness is DEC part number 17-01311-01
and uses white connectors and various colored wires. If you have yellow con-
nectors or a webbed cable (rather than individual wires) you have a potential
safety hazard. Again, this *only* applies to BA23 boxes. If you're not comfort-
able with doing this yourself, you can get DEC to look at it (which will cost 
you if you don't have a contract).

	Terry Kennedy		Operations Manager, Academic Computing
	terry@spcvxa.bitnet	St. Peter's College, US
	terry@spcvxa.spc.edu	(201) 915-9381