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Re: General Stuff(tm)
Posted: 03 Feb 2024 12:49
by stephen_usher
OK, so the transistor Q1 tests bad. Unfortunately the can is corroded just where the part number is so I can only just see that it ands in "2A" which isn't very useful as many transistor numbers end in this combination.
Also, the PCB of the power supply is crumby. It's unsually double sided but the vias seem to be made of cheese. Just putting the Hakko on the legs of the component long enough to melt the solder lifted the pads.
Re: General Stuff(tm)
Posted: 03 Feb 2024 17:48
by stephen_usher
Loks like the transistor was a simple 2N2222A. I have some so I can try it.
Re: General Stuff(tm)
Posted: 03 Feb 2024 19:40
by stephen_usher
Nope. No change. Oh well.
I'd better order a Meanwell RT-85B as a replacement.
Re: General Stuff(tm)
Posted: 03 Feb 2024 20:06
by rubber_jonnie
stephen_usher wrote: 03 Feb 2024 12:00
It needs the PSU's 12V to power the display. I could potentially lash up a luminance+sync->composite sync cable but far better to get the PSU working.
It's quite possible that it's the Zener. I'll have to see.
I've had to go into work this morning as the virtual infrastructure lost connectivity to the new storage, on which all the VMs reside. The two Dell 10Gb switches had both reverted to an older set of settings for some reason and lost the new VLAN configuration I set six months ago and definitely saved.
Sometimes I really dislike modern technology...
Re: General Stuff(tm)
Posted: 03 Feb 2024 20:07
by rubber_jonnie
stephen_usher wrote: 03 Feb 2024 19:40
Nope. No change. Oh well.
I'd better order a Meanwell RT-85B as a replacement.
Power supplies, my other nemesis. Thank god for Meanwell.
Re: General Stuff(tm)
Posted: 03 Feb 2024 22:32
by PhilC
I think I’d ditch the old PSU as well once the tracks started lifting.
Re: General Stuff(tm)
Posted: 03 Feb 2024 22:37
by stephen_usher
PhilC wrote: 03 Feb 2024 22:32
I think I’d ditch the old PSU as well once the tracks started lifting.
Well, it's not the tracks as much as the vias dying. As I said, it's a two layer board, which is very unusual for a power supply.
Re: General Stuff(tm)
Posted: 04 Feb 2024 13:57
by stephen_usher
Hmm... Looks like the "power good" detection circuit in the OPD monitor's power supply is on the blink now. Need to investigate.
Re: General Stuff(tm)
Posted: 04 Feb 2024 14:35
by rubber_jonnie
stephen_usher wrote: 04 Feb 2024 13:57
Hmm... Looks like the "power good" detection circuit in the OPD monitor's power supply is on the blink now. Need to investigate.
Ahh Damn...
Re: General Stuff(tm)
Posted: 04 Feb 2024 14:39
by PhilC
The joys of owning retro computers. Broken, then
Fixed, shortly followed by broken again.