Search found 120 matches

by Vyper68
Thu Sep 10, 2020 6:35 am
Forum: Technical questions
Topic: Microdisc Service Manual
Replies: 17
Views: 1208

Re: Microdisc Service Manual

If you measure between the middle leg and the one nearest to RV1 on the board I'm getting .925. Make sure you have this little wire in place. Hi Steve can you post a picture as the whole of the underside of the Cumana PCB please. I hadn’t fitted the wire so that maybe why it’s hanging, but I can se...
by Vyper68
Wed Sep 09, 2020 3:22 pm
Forum: Technical questions
Topic: Microdisc Service Manual
Replies: 17
Views: 1208

Re: Microdisc Service Manual

... but power seems important !!! I'm fairly sure you do need power for it to work :D Is it variation in the grounding arrangements between the two boards (that whole thing on the Cumana schematic about cutting the ground track so that things AREN'T connected) -- maybe this is biting you in some wa...
by Vyper68
Tue Sep 08, 2020 3:53 am
Forum: Technical questions
Topic: Issue 2 Oric-1 Repair
Replies: 21
Views: 896

Re: Issue 2 Oric-1 Repair

I was thinking of setting the Internal 3” drive to be drive “B” using the dip switch and connecting my Gotek as drive “A” that way I could load Sedoric and see if I can get the internal drive to do a “DIR” or format a spare 3” disk I have from my CPC.
by Vyper68
Mon Sep 07, 2020 5:55 pm
Forum: Hardware hacks and extensions
Topic: TSN 1-2450A instead of LM7905
Replies: 20
Views: 1608

Re: TSN 1-2450A instead of LM7905

I fitted the 2450A regulator again and the Atmos does boot if you short the Reset pin so I fitted a 4.7uf cap and had no joy but when I fitted a 10uf Capacitor the Atmos boots up so thanks to Mikeb for the tip on replacing the Cap with a higher value. OK, so that shows you how slow the module is at...
by Vyper68
Mon Sep 07, 2020 4:40 pm
Forum: Technical questions
Topic: Issue 2 Oric-1 Repair
Replies: 21
Views: 896

Re: Issue 2 Oric-1 Repair

Chema wrote:
Mon Sep 07, 2020 4:33 pm
I also guess you checked for current consumption, just in case... you can find some reference values for both the 5 and 12v in standby and in operation in the manual linked in a previous post.
I haven’t done that but that is another thing to check :)
by Vyper68
Mon Sep 07, 2020 4:39 pm
Forum: Technical questions
Topic: Issue 2 Oric-1 Repair
Replies: 21
Views: 896

Re: Issue 2 Oric-1 Repair

I took the 3” Drive apart and disconnected the logic board. The Index light sensor was pushed down so I straightened it up. Reflowed the pin headers for the connectors. Refitted it all back together and stuck a disk in and saw the LED and heard it spin up. So I didn’t do a great deal but something I...
by Vyper68
Mon Sep 07, 2020 3:43 pm
Forum: Hardware hacks and extensions
Topic: TSN 1-2450A instead of LM7905
Replies: 20
Views: 1608

Re: TSN 1-2450A instead of LM7905

I am pleased I got to the bottom of it with Mikeb’s help. Sorry to hear about your Cumana Reborn issues HigashiJun, hope it works okay from now on.
by Vyper68
Mon Sep 07, 2020 3:38 pm
Forum: Technical questions
Topic: Issue 2 Oric-1 Repair
Replies: 21
Views: 896

Re: Issue 2 Oric-1 Repair

This 3” Drive is a direct drive model so no drive belts Chema. I have managed to get it to fire up and the LED’s light up correctly. All I get now is “ Insert system disk “ and after a while “ No operating system on disk “ so I have made some progress. Maybe the drive is out of alignment? I know my ...
by Vyper68
Mon Sep 07, 2020 12:12 pm
Forum: Hardware hacks and extensions
Topic: TSN 1-2450A instead of LM7905
Replies: 20
Views: 1608

Re: TSN 1-2450A instead of LM7905

I fitted the 2450A regulator again and the Atmos does boot if you short the Reset pin so I fitted a 4.7uf cap and had no joy but when I fitted a 10uf Capacitor the Atmos boots up so thanks to Mikeb for the tip on replacing the Cap with a higher value.
by Vyper68
Sun Sep 06, 2020 9:30 pm
Forum: Technical questions
Topic: Issue 2 Oric-1 Repair
Replies: 21
Views: 896

Re: Issue 2 Oric-1 Repair

Yeah my bad it’s a HFD-305S from a Microdisc and I had found a manual for the 305 and the Jumpers are set correctly. So I think I need to get my magnifying glass and check. The Microdisc is a friends and it was working for a short while and then started to have formatting problems then read and writ...
by Vyper68
Sat Sep 05, 2020 10:02 pm
Forum: Technical questions
Topic: Issue 2 Oric-1 Repair
Replies: 21
Views: 896

Re: Issue 2 Oric-1 Repair

Hey Mike have you ever had any experience troubleshooting the 3” drive in a Microdisc ( Hitachi HFD-305SE ) before? I have one here that spins up but in all other respects seems unresponsive. The logic board is sound as it works with my Gotek drive.
by Vyper68
Fri Sep 04, 2020 6:43 pm
Forum: Technical questions
Topic: Issue 2 Oric-1 Repair
Replies: 21
Views: 896

Re: Issue 2 Oric-1 Repair

Fixed the loudspeaker now ( dry solder joint ) so we have a working Oric-1 issue 2 :D
by Vyper68
Fri Sep 04, 2020 5:49 pm
Forum: Technical questions
Topic: Issue 2 Oric-1 Repair
Replies: 21
Views: 896

Re: Issue 2 Oric-1 Repair

Yeah! The Oric-1 lives BUT the loudspeaker is not working. I replaced the LM386 and 220uf capacitor so that’s not the problem. I thought it had let go when I couldn’t even hear the normal Oric background “noise” when plugged and sat idle. Anyone have a spare or know of a source of spares or failing ...
by Vyper68
Fri Sep 04, 2020 2:36 pm
Forum: Technical questions
Topic: Issue 2 Oric-1 Repair
Replies: 21
Views: 896

Re: Issue 2 Oric-1 Repair

Yes 11 and 13 were shorted by a tiny bit of solder across two tracks where the solder mask was missing :oops: The PCB is definitely laid out differently as some of the service mods like putting a 220Ohm resistor on pin 2 of IC21 the place where you cut doesn’t exist. The track is on the top and goes...
by Vyper68
Thu Sep 03, 2020 5:13 pm
Forum: Technical questions
Topic: Issue 2 Oric-1 Repair
Replies: 21
Views: 896

Re: Issue 2 Oric-1 Repair

Hi Mike I am not sure currently but the MA Lines from the ULA and Address Lines from the ROM all follow the schematic I have but on the "other" side of the 74LS257's going to the RAM I get the following... I think I am going to have to take the sockets off and check the tracks. I clipped the old RAM...