After you check the obvious brightness control you can look and see if you could get a look at the CRT neck and the socket, checking if the picture tube filament is actually lit. If it is, the next thing is to check to see if there is high-voltage, (using the proper tester of course) with probe and meter. If it has high voltage you should have a raster or some sort of brightness. I should be at the next workshop on Saturday ( if no hamfest is conflicting with that date) We recently had a person at the last workshop who had a COMPAQ portable and he too had a similar issue we had found that the power supply was not supplying the CRT board properly but with the correct voltages and he was looking up a schematic diagram. specifically it was like a 30 or 15 Volt supply issue Could be bad capacitors on the power supply board, not sure. Mike R. Sent from: My extremely complicated, hand held electronic device.
On Aug 1, 2019, at 1:24 PM, Dean Notarnicola via vcf-midatlantic <vcf-midatlantic@lists.vcfed.org> wrote:
I know it sounds obvious, but try the brightness control. Exactly which model is it?
On Thu, Aug 1, 2019 at 1:14 PM Douglas Perry via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
Excuse me if I'm coming off a bit over eager.
Now that I'm signed up for this months workshop I was hoping to get some tips on how to properly prepare (supplies needed, ect..)
I'm bringing a Compaq Portable which has only been owned by my family. It was stored in a guest room of a finished basement since 1993. Not sure where they kept it before that.
I testing I've done so far is to simply plug it in and turn it on (after giving it a week in a temp/humidity controlled room). The PSU and fan came to life nicely, the CRT is making a familiar hum but I get nothing on the screen not even a blinking cursor. I'm not sure if I should expect an error with no disk? I also don't hear any drive noise.(I have no disks)
I have a fairly decent toolkit for repairing current machines, as well as a soldering iron, and multimeter.
From my research I'm going to go ahead and assume the capacative pads for for the keyboard are bad and just order a new set.
I've searched fairly well and have not found a reputable place to buy a 5.25 floppy pre-loaded with MS-DOS 3.3 (which sounds like the best option).
So after that ramble here are my questions. Is there anything else you all would recommend me bringing?
When is the best time show up?
Is there anything else I should know or be doing to get ready?
Thanks, Doug P.