Search found 7 matches

by ozzybetts
Tue Jun 16, 2020 11:48 am
Forum: Hardware
Topic: MZ 80K repair project
Replies: 24
Views: 8385

Re: MZ 80K repair project

Sorry, that's beyond my skills. Not at all; thank you for your support so far. Very much appreciated Sounds like the horizontal synch has failed. Check test points 13 to 21 on the video board with an oscilloscope, ( see page 40 of the MZ80K Service Manual) and compare with traces on pages 19/20. I ...
by ozzybetts
Sat Jun 13, 2020 2:46 pm
Forum: Hardware
Topic: MZ 80K repair project
Replies: 24
Views: 8385

Re: MZ 80K repair project

Replaced the 4 blue tantalum capacitors with new electrolytic caps. It works!!! :D All output votlages correct! I noticed in the DexterTechLab video that the larger capacitors that I was having trouble finding, were replaced with different ones of a slightly higher capacity and that clearly works! S...
by ozzybetts
Thu Jun 11, 2020 9:57 am
Forum: Hardware
Topic: MZ 80K repair project
Replies: 24
Views: 8385

Re: MZ 80K repair project

Ah yes! You are probably right about the F401 fuse having already blown beforehand. Althought I had removed the PSU, I had not checked the fuses before the first powerup, and did not see which fuse(s) blew as the case was on, just saw the flash :) I will report back when I have replaced the blue tan...
by ozzybetts
Thu Jun 11, 2020 5:56 am
Forum: Hardware
Topic: MZ 80K repair project
Replies: 24
Views: 8385

Re: MZ 80K repair project

Interesting enough, several researches about MZ-80 K PSU failures are related to tantalum caps (four blue ones) issues. by replacing the blue capacitors which are part of the voltage setting circuit I'm replacing those today; here's hoping! That gunk is probably just kind of glue used during assemb...
by ozzybetts
Tue Jun 09, 2020 11:34 am
Forum: Hardware
Topic: MZ 80K repair project
Replies: 24
Views: 8385

Re: MZ 80K repair project

Thanks for the link to that file. Looks very interesting. Here are links to the original resolution images already posted : https://drive.google.com/file/d/15zwgyCOwT9KyCMqOsr8ofB2jU2kIgvPV/view?usp=sharing https://drive.google.com/file/d/163l0QxQEbBHo4H79c6IsuDTUdFnASkg7/view?usp=sharing https://dr...
by ozzybetts
Tue Jun 09, 2020 9:18 am
Forum: Hardware
Topic: MZ 80K repair project
Replies: 24
Views: 8385

Re: MZ 80K repair project

Thanks for your reply, and also for passing it onto others :) One answer from Melissa Wells for the worst case: "i replaced mine with a meanwell one and it works a treat". It is great news that others have had success using modern power supplies to run these computers; very promising. May ...
by ozzybetts
Sun Jun 07, 2020 2:34 pm
Forum: Hardware
Topic: MZ 80K repair project
Replies: 24
Views: 8385

MZ 80K repair project

Hi all, First time posting here. Hoping you are all well. I recently aquired a MZ80K with the hope of getting it working, so my students can have a go with using it. Apart from being filthy, the 'first' problem I have found is that the PSU does not work. https://1.bp.blogspot.com/-Uz0U6CrH40k/Xtz2Rq...