Re: Static PET PSU questions

On 10/6/09, M H Stein <dm561@torfree.net> wrote:
> Ah, so the 9" non-CRTC monitors are all the same frequency/polarity after
> all? That was certainly my understanding.

Mine as well.

> Clever and convenient, the way the power pins are arranged; I'll have to
> look at my 4032 & 8032 to see if they're the same.

AFAIK, they are the same - there's one 5-pin harness design and one
8-pin design with a key pin - all the way up to the SuperPET

> Make sure they're clean and good tension on the socket. Old PC power
> supply connectors work well when the PET one burns up...

Yep.  I've seen plenty of oxidized connectors.

> I never looked, but you're right; I've got two 2001-8s and one has the
> rectangular holes and the other the triangles. Didn't I send you any (8)
> washers with that board?

I have the 6-32 hardware for bolting down the 7805s, but since I
removed the drilled-out pop rivets just recently, I think I would have
noticed any thin washers.  I was _expecting_ thin washers there, but I
couldn't verify them from any photographs I could find on the web.

> I don't see any plastic washers, but there are
> thin (metal?) washers around the rivets between the heatsink and the PCB,
> lifting the heatsinks so they don't touch the pads (although there's still
> very little clearance around the leads).

Right.  Just lifting the heatsink a wee bit off the board would take
care of the issue.

> The board with rectangular holes
> is a little later than the triangle one, so maybe they did have a few boards
> come back that had had 9V Vcc on them...

Perhaps.  As I said, the same style of heat sink is on the video board
from this later (2001N/3032) PET with the rectangular hole.  I did
find a photo of a 2001-8 with rectangular holes in the heat sinks, and
they are identical in proportion to the ones in my present monitor.

> Sounds like you're almost there; good luck with that video issue.

I think so.

> Let me know if I can help (with waveforms or whatever).

I will let you know.  I do have other working TTL-video PETs, so I can
do a side-by-side comparison of the video chain to backtrace where
things go off the rails, but essentially, I need to spend more time
understanding the video timing chain anyway.

-ethan

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