archive.worldofdragon.org

Try lighter fuel to take away the seals without breaking them, and tell us which motherboard part number it has.

Thanks Robcfg, that certainly a good tip that I'll try.

Well it is this version of the Dragon 32 Motherboard:

http://archive.worldofdragon.org/index. ... ssue5).jpg

Mine had a few labels on some of the chips.

It has Z105226 on a stamped piece of paper just above IC26.

It had a long sticker with a handwritten AT on it across IC 14, IC27, IC29, IC31, and IC33. Is that the ROM?

It also has a small circular sticker with a handwritten 31 on it on top of IC35.

There is a sticker in the bottom right hand corner RACE M 105226.

I left her switched on for 20 minutes or so and then tried to determine if any chips seemed hotter than others. I'm assuming the RAM is the group of 16 ICs at the top right.
If so, I found that the top row was definitely warmer than the bottom row. It was hard to isolate just one warmer chip, but I would say that the vicinity of C3, C4, and C5 was the warmest area.

Hopefully this can be of some help to someone, and maybe somebody could repair my poor broken Dragon 32.

It would be a shame to not have it properly working. I always thought it looked like a good computer back in the 80s, despite eventually getting a VIC 20. I was surprised at the time when they went bust. Having one now (actually this broken one is the first time I've ever used a Dragon), I can see that they deserved better than the fate they had. I would certainly like to give a home to a working example in my collection.
Plus I have just got a book of type ins that I want to type in and upload to share, if they're any good. If they don't work, maybe we could work on them together to figure out where the bugs are?

Here's hoping anyway. Thank you all for your help so far.

The schematics don't show the second bank (IC36 - IC43). My guess is the faulty one is IC42 or IC7 (check pin 2 is connected between those two, I'm guessing at the order of the second bank).

Maybe you want to have a look at:
viewtopic.php?f=8&t=3144

I expanded my D32 and I've still got the original 16K RAMs.
Where you from (->shipping costs)?

sixxie wrote:The schematics don't show the second bank (IC36 - IC43). My guess is the faulty one is IC42 or IC7 (check pin 2 is connected between those two, I'm guessing at the order of the second bank).

Hi Sixxie. I clicked on the link in my post and realised that it actually doesn't even work! Not sure why that is.

As hopefully you were able to deduce it was the Dragon MkII issue 5 board.

When I mentioned C3, 4, and 5, I actually meant IC 3, 4, and 5; I just didn't have my reading glasses on at the time!

I shall certainly open the Dragon up again in the morning and check the connection that you are referring to.

Rolo wrote:Maybe you want to have a look at:
viewtopic.php?f=8&t=3144

I expanded my D32 and I've still got the original 16K RAMs.
Where you from (->shipping costs)?

Hi Rolo. That is certainly an impressive project that you undertook there!
I'm very interested in those RAM chips that you have. I am in the UK. When you speak of shipping do you mean for the chips, or would you be able to carry out the surgery on the poor, sick Dragon?

Thank you everybody for your interest and support in this. One thing is clear in my mind; I am determined that this Dragon 32 will be saved. It is in far too good condition not to be saved. The motherboard was lovely and clean; unlike nearly every ZX Spectrum that I have ever had. Mostly they have even contained dead creepy crawlies and flaking/bubbling of the tracks. None of that in the Dragon.
The case and keyboard was rather dirty, but after a clean up, it's all in good order. No breakages, no missing keys and they all work, so this is a computer that needs to be saved.

Absolutely!

And when you start realizing all the Dragon can do, you'll be amazed. It really is an awesome machine!

Well I took the whole motherboard out and had a look at Side 1. There was a fair bit of bubbling and flaking there, but it mostly looks OK. Like I said earlier I have seen far worse in Sinclair Land. All looks the same with IC7 and IC42, except that the soldering on IC7 doesn't look quite so good, that is it is flat to the board rather than like a nipple. I wonder if it could be a bad solder joint?