MicroVAX II Always in Language Mode

[leaknoil]

I was playing with my mv2 today and all of a sudden it will only boot in language mode. The mode where it asks you for a language before going anywhere. It never did before.

The switch isn't in language mode and no change exercising it. Ribbon cables are fine and I didn't touch anything in there anyway. They test fine for continuity. All have been reseated several times.

Both normal and language mode do the same thing. Language mode. Loopback mode setting acts as loopback mode usually does.

The only thing bad that happened today was a couple of sudden power outages. However it booted up fine after. It was only after I shut it down for awhile later and booted it up again that it's stuck in language mode.

Any ideas ? Obviously not a big deal on a computer I only play with once in awhile but, it's bugging me.

 

[gslick]

Is the battery good? I have removed the batteries on all of my Microvax bulkheads before they leak everywhere, so I get that prompt on every power up.

 

[leaknoil]

Ahh that is probably it then. It must have died if that's what happens when there is no battery. Probably a good idea to toss it before it leaks anyway.

They still sell these batteries ?

 

[gslick]

Those packs are made of (3x) AAA Ni-Cads. You used to be able to order a set of (3x) AAA Ni-Cads bonded together to custom order from Digi-Key, but Panasonic doesn't appear to make AAA Ni-Cads anymore. You might be able to get AA Ni-Cads but then you would have to work up a non-standard way to mount then.

 

[Chuck(G)]

Just go over to eBay and search on "3.6V battery". You'll get lots of choices--both Nimh and NiCd. They're still used in a lot of devices and they're stupid cheap from China.

 

[RSX11M+]

You might want to try your luck with a BFC. Digikey lists lots of them, sizes over 1F and 5V. I've switched lots of consumer electronics and ancient computers over to these. Gets you out of worries about corrosion altogether.

 

[leaknoil]

I've never used a supercap before. How long to they hold a charge for ? I don't turn this MicroVAX on very often.

You might want to try your luck with a BFC. Digikey lists lots of them, sizes over 1F and 5V. I've switched lots of consumer electronics and ancient computers over to these. Gets you out of worries about corrosion altogether.

 

[RSX11M+]

Is a BFC appropriate?...

Is a BFC appropriate?...

This is a hard question to answer directly, not knowing the MicroVAX II intimately. [is this a BA123?]

Let me answer generally...

• Most systems that employ NiCad memory backup, trickle charge them while powered off, but connected to AC. If this is the case, a BFC is most ideal because it only supports the memory (and/or RTC) while power is absent. In most cases I'm aware of, a suitable BFC can support these for a week or two.

More if it's only memory or if it's a particularly miserly circuit.
​

• If however, the system only charges the NiCad while it's operating, and you leave it off for significant periods, a BFC will likely need to be pretty big, but not impossible - to be practical.

So, if it were me, I'd try to determine which case the MicroVAX II is. If you're handy with a voltmeter, it will give you the most direct answer. My read of the BA123 User Guide is that it is indeed the former type, and that it's Battery Backup Unit (BBU) is a 3-cell side-by-side pack that should be easily replaced with a more standard wired type. [aka portable phone handset] You may need to transfer the connector and do a little soldering.

But from my read, I wouldn't hesitate to try a BFC. You'll need to check the open-circuit charging voltage to size the BFC appropriately. Other than that, it's just a polarity check and packaging exercise. [even so for the battery]

 

[leaknoil]

This is a hard question to answer directly, not knowing the MicroVAX II intimately. [is this a BA123?]

It is. I'll probably just stick something a little more common in there but, the supercap is an interesting bit of tech. Might be great for current pc's where it is used every day. I'd love to see those coin batteries go away.