Search found 612 matches

by 1024MAK
31 Jul 2020 01:29
Forum: HARDWARE
Topic: No picture.
Replies: 91
Views: 4081

Re: No picture.

I *think* that listing is the larger conductor size. But the smaller conductor size would be fine as well.

I’m going on the current rating in the details section.

Mark
by 1024MAK
30 Jul 2020 19:45
Forum: HARDWARE
Topic: No picture.
Replies: 91
Views: 4081

Re: No picture.

Looks okay. Shame the listing is a little vague on which conductor size it is. But the overall size is the same, so if the larger conductor size is supplied, it should not be a problem.

Mark
by 1024MAK
29 Jul 2020 23:17
Forum: HARDWARE
Topic: No picture.
Replies: 91
Views: 4081

Re: No picture.

Steven.G wrote:
29 Jul 2020 19:07
OK, any particular specifications or recommendations?

Steve..
I have used this cable from Rapid https://www.rapidonline.com/kabeltronik ... 61-49-0478 in the past. But it’s now discontinued:-(

But anything similar should be fine.

Mark
by 1024MAK
29 Jul 2020 16:20
Forum: HARDWARE
Topic: No picture.
Replies: 91
Views: 4081

Re: No picture.

If the cable has started to fail, I recommend renewing it completely.

Mark
by 1024MAK
29 Jul 2020 13:08
Forum: HARDWARE
Topic: No picture.
Replies: 91
Views: 4081

Re: No picture.

Rather than trying to hold a meter probe on pin 16, it’s far easier to use the case of the modulator ;)

Mark
by 1024MAK
29 Jul 2020 13:05
Forum: GENERAL DISCUSSIONS
Topic: MTX 512 (debugging thread)
Replies: 61
Views: 9372

Re: MTX 512 (debugging thread)

Apart from the data in (D) and data out (Q) pins (2 & 14), ensure by continuity testing (or by using the 200 ohm resistance range) using a multimeter that all like numbered pins on each video DRAM socket are connected to all the other video DRAM sockets. So pin 3 on one video DRAM socket should have...
by 1024MAK
29 Jul 2020 00:42
Forum: HARDWARE
Topic: No picture.
Replies: 91
Views: 4081

Re: No picture.

No, there is no need to do the light bulb test anymore.

You can test all the voltages on any of the 4116 DRAM chips.
Over on Sinclair ZX World there is a topic with the pin-out of the 4116 DRAM chips, click here ;)

Mark
by 1024MAK
28 Jul 2020 20:16
Forum: HARDWARE
Topic: No picture.
Replies: 91
Views: 4081

Re: No picture.

Other recommendations: Capacitor C53 should be renewed as a preventative measure. The voltages on the +12V, +5V and -5V supplies should be tested to confirm that they are all now within specification. +5V should be within +/-5% (+4.75V to +5.25V). +12V should be within +/-10% (+10.8V to 13.2V) but a...
by 1024MAK
28 Jul 2020 20:01
Forum: HARDWARE
Topic: No picture.
Replies: 91
Views: 4081

Re: No picture.

It’s generally undesirable to try to fuse the outputs of a mulitapped transformer where multiple taps are in use to feed rectifier circuits. That exactly describes the situation with the MTX. The trouble with putting a fuse between the transformer and the rectifier diodes, is that the current can st...
by 1024MAK
23 Jul 2020 21:19
Forum: HARDWARE
Topic: No picture.
Replies: 91
Views: 4081

Re: No picture.

A method of testing that limits the fault current is to use a normal light bulb (I recommend a 40W or 60W, you can try a 100W at your own risk, whatever the wattage it MUST be a filament type only). Beware that this will be at mains voltage. Connect up as per the diagram below:- https://stardot.org....