Topic: Need some help repairing an Oric 1, no keyboard input  (Read 1585 times)

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Offline Revo

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Need some help repairing an Oric 1, no keyboard input
« on: August 20, 2015, 05:44:47 PM »
Hi All

I just purchased an Oric 1 48K to add to my collection of vintage computers.
It didn't come with a power supply but I found a 9V 1A supply that fitted that came with an old broadband router (maybe it's not smoothed enough and is what is causing the problem).
I connected up to a TV and I get the  Oric screen showing "ORIC EXTENDED BASIC V1.0  47870 BYTES FREE   Ready" and a flashing cursor but when I type I get nothing.
I've already taken it apart and pressed in the socketed chips and checked the pins from the motherboard to the keyboard.
Has anyone any suggestions of what I could try next?

Thanks for looking ;)

Offline AndyRCM

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Re: Need some help repairing an Oric 1, no keyboard input
« Reply #1 on: August 20, 2015, 09:15:44 PM »
Hi Steve,
Hmmmm - One thing I do know (from experience) is that the Oric is a funny system when it comes to PSUs.
However I have also found that a ZXSpectrum PSU - WITH THE POLARITY CHANGED - is ideal - if you have a spare of course! ;)
If you are ever around the Leicestershire area please do pop it in so we can take a look for you? ;)
Cheers
A
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Offline Revo

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Re: Need some help repairing an Oric 1, no keyboard input
« Reply #2 on: August 20, 2015, 10:19:41 PM »
I'll try the Spectrum PSU thanks.

I found a wiring diagram for the keyboard and have found that the keys work when they are pressed.  I wonder if the 4015 chip has gone on the keyboard, I'm wondering if I can apply voltage to the chip and see if I get an output, I'm no expert on these things but I do have some knowledge and some equipment.

Offline carlsson

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Re: Need some help repairing an Oric 1, no keyboard input
« Reply #3 on: August 27, 2015, 11:29:16 PM »
Remember to reverse the Spectrum polarity so you get centre positive which is what the Oric will want.

I have an Oric on which certain keys lock up the machine when pushed. I got help replacing the 6522 previously, but I have understood that the raw decoding of the keyboard goes through the AY-3-8910 sound chip, also known as PSG. I haven't got to replace that one yet, but I hope when replacing it, my Oric will entirely spring to life. At least a majority of the keys register correctly on mine.

Offline Womble

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Re: Need some help repairing an Oric 1, no keyboard input
« Reply #4 on: September 04, 2015, 04:29:27 PM »
If you have a flashing cursor then the computer is running, so the PSU is fine.
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