Search found 120 matches
- Thu Sep 10, 2020 6:35 am
- Forum: Technical questions
- Topic: Microdisc Service Manual
- Replies: 17
- Views: 2515
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...
- Wed Sep 09, 2020 3:22 pm
- Forum: Technical questions
- Topic: Microdisc Service Manual
- Replies: 17
- Views: 2515
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...
- Tue Sep 08, 2020 3:53 am
- Forum: Technical questions
- Topic: Issue 2 Oric-1 Repair
- Replies: 21
- Views: 2453
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.
- Mon Sep 07, 2020 5:55 pm
- Forum: Hardware hacks and extensions
- Topic: TSN 1-2450A instead of LM7905
- Replies: 20
- Views: 3317
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...
- Mon Sep 07, 2020 4:40 pm
- Forum: Technical questions
- Topic: Issue 2 Oric-1 Repair
- Replies: 21
- Views: 2453
- Mon Sep 07, 2020 4:39 pm
- Forum: Technical questions
- Topic: Issue 2 Oric-1 Repair
- Replies: 21
- Views: 2453
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...
- Mon Sep 07, 2020 3:43 pm
- Forum: Hardware hacks and extensions
- Topic: TSN 1-2450A instead of LM7905
- Replies: 20
- Views: 3317
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.
- Mon Sep 07, 2020 3:38 pm
- Forum: Technical questions
- Topic: Issue 2 Oric-1 Repair
- Replies: 21
- Views: 2453
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 ...
- Mon Sep 07, 2020 12:12 pm
- Forum: Hardware hacks and extensions
- Topic: TSN 1-2450A instead of LM7905
- Replies: 20
- Views: 3317
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.
- Sun Sep 06, 2020 9:30 pm
- Forum: Technical questions
- Topic: Issue 2 Oric-1 Repair
- Replies: 21
- Views: 2453
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...
- Sat Sep 05, 2020 10:02 pm
- Forum: Technical questions
- Topic: Issue 2 Oric-1 Repair
- Replies: 21
- Views: 2453
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.
- Fri Sep 04, 2020 6:43 pm
- Forum: Technical questions
- Topic: Issue 2 Oric-1 Repair
- Replies: 21
- Views: 2453
Re: Issue 2 Oric-1 Repair
Fixed the loudspeaker now ( dry solder joint ) so we have a working Oric-1 issue 2 

- Fri Sep 04, 2020 5:49 pm
- Forum: Technical questions
- Topic: Issue 2 Oric-1 Repair
- Replies: 21
- Views: 2453
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 ...
- Fri Sep 04, 2020 2:36 pm
- Forum: Technical questions
- Topic: Issue 2 Oric-1 Repair
- Replies: 21
- Views: 2453
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...
- Thu Sep 03, 2020 5:13 pm
- Forum: Technical questions
- Topic: Issue 2 Oric-1 Repair
- Replies: 21
- Views: 2453
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...