Sinclair ZX80 / ZX81 / Z88 Forums

Both of mine have video problems...caps?

gammaray wrote: ↑Wed Nov 21, 2018 12:03 am Both of mine have video problems...caps?

Symptoms?

Mark

Keeping in mind that the units have both a RF and a composite output,
and that I used the same power supply.

TS-2068-ONE has no color but does black and white cartridges just fine.

TS-2068-TWO shows vertical bars and other video failure symptoms.

Checking for the powersupply:
http://www.old-computers.com/museum/com ... st=1&c=634
says "DVE power supply, 15 V at 1 Amp DC, and with the outside sleeve of the plug positive and the inside negative."

Also asking someone locally here about their power supply...

In contrast, the Spectrum failed when I used 12V so I went to a 9V 2A switching power supply.

For Timex Sinclair 2068 you should use a 15Vdc/1A power supply, 9V supply is too low.

Maybe why it was inconsistent. I believed I used a 12V PSU.

I was getting ready to wash in the dishwasher or replace all the caps.

Fixes Apple Macintosh boards from cap leakage. See YT videos.

Gammaray,

What is your PSU's voltage reading, from your multimeter's view? Maybe your PSU have a problem with blown diode(s). Does your PSU smell burnt? Do you have an oscilloscope?

I have my TS2068 and a PSU with its label. DVE Model No. DV-141A "FOR USE WITH COMPUTER".

DesSony

That is the issue. I used the PSU that was in the original box without checking that it was the right one. Now no telling since it probably was the wrong one, unless I misplaced it. So far nothing that I have is 15V and still looking.

Gammaray,

Can we find a schematic for the TS2068?

DesSony

Found this.

Excerpt...

Gammaray,

After a few minutes of using a search box, I also found the schematic with its lines cleaner. And only a page.

https://8bit-museum.de/scans/timex/ts2068schematic.jpg

However, we still can use both of these drawings.

Cheers,
DesSony