Commodore 3022 Printer - UK Vintage Radio Repair and Restoration Discussion Forum

ScottishColin · 17th Aug 2023, 1:26 pm

Onto the next thing.

I've cleaned this all up and checked the voltages and they look good. I've freed up all the mechanical bits and they move smoothly.

What's supposed to happen at powerup is that the carriage homes itself. Also, tere is a feed button on the front which when pressed lights the LED next to it but no feed occurs.

Anyone care to help get me started on this one?

Anyone fixed up any old printers?

TIA.

Colin.

https://archive.org/download/commodo...ce%20Guide.pdf

SiriusHardware · 17th Aug 2023, 1:49 pm

If there are mechanical issues then I think TonyDuell is going to be your man here, but:-

First thing I notice on the diagram is that there is a 'case closed' switch which presumably detects when the lid is open. Quite often, printers won't move or do anything while the lid is open or while they THINK the lid is open, so check that the switch is operating in the expected manner.

What happens if you try to invoke the self-diagnostic test? Starting with power off, press and hold down line feed, and while doing so, turn the power on? (Have some paper loaded in case it does do something).

ScottishColin · 17th Aug 2023, 2:38 pm

No self-test activity after putting it all back together. I couldn't see any switches near the case anywhere fyi.

It's worth noting that this printer is a 3022. I have linked to the 2022 manual as

1) I cannot find for love nor money any 3022 manuals and
2) I've been told that the 3022 and the 2022 are UK (European?) and US versions of the same device

I don't know that this is true, but it's all I have right now.

Also worth noting that I'm a little confused by the schematics in that document but that my motherboard is on page 19.

Colin.

ScottishColin · 17th Aug 2023, 3:42 pm

Here's the only other (inconclusive) thread I can find about a 3022.

https://forum.vcfed.org/index.php?th...-defect.57211/

Colin.

SiriusHardware · 17th Aug 2023, 3:45 pm

The mainboard being the same is a good start.

You say you have checked the supplies (including the +24V/25V supply?). I'll take your word for that and move on.

With very little in the way of expected activity, try approaching it as you would any other microprocessor system. Is it easy to get at the mainboard to make measurements from it while the power is on?

SiriusHardware · 17th Aug 2023, 3:53 pm

Ref: #4, there is a link in the first post which takes you to yet another possible circuit diagram. I think the first thing is going to have to be working out which of those available corresponds to your PCB.

If you think your PCB (and by the way, how many PCBs are there in the machine?) corresponds to the layout in the first manual you linked to then there is a good chance one of the diagrams in that manual does too.

SiriusHardware · 17th Aug 2023, 4:03 pm

If you can get to the mainboard while power is on, try measuring the frequencies on:
IC 3C pin 1 (8MHz?)
IC 3C pin 12 (500KHz?)
IC 3C pin 14 (1MHz?)

This is to establish whether your PCB does or does not correspond to one of the circuit diagrams.

Remember to use a significantly higher scope sampling frequency than the expected frequencies when looking at these pins.

ScottishColin · 17th Aug 2023, 4:16 pm

Attached is a photo of the motherboard.

There is a further small circuit board with (I think) just resistors/capacitor on it too.

Colin.

ScottishColin · 17th Aug 2023, 4:47 pm

Sampled at 48Mhz setting:

IC 3C pin 1 - 6MHz
IC 3C pin 12 - 500KHz
IC 3C pin 14 - 1MHz

Colin.

SiriusHardware · 17th Aug 2023, 5:02 pm

Not a bad start - the MHz value on Crystal CR1 on the circuit diagram is unreadable, but you should be able to read it off the crystal itself (Normally, crystals have their operating frequency marked on them). Edit: Ah, actually having now looked at your recent photos I see that it is a 6MHz crystal.

What frequency do you see on IC 8B (6504) pin 27?

Immediately after you switch the unit on, what state or activity do you see on IC 7A pin 10?

SiriusHardware · 17th Aug 2023, 5:13 pm

Regarding the other half hidden PCB, I see at least half a dozen transistors on there so I think that is going to be the motor control PCB, which corresponds to PDF page 20 of the manual you originally linked to.

At the moment I am going on the assumption that pages 18-21 (sheets 1-4 of 4) are the diagrams which are relevant to your version.

ScottishColin · 17th Aug 2023, 5:17 pm

1Mhz on pin 27 8B.

No activity at all on pin 10 of 7A - no waveform, no voltage, no frequency.

Colin.

Quote:

Originally Posted by SiriusHardware

Not a bad start - the MHz value on Crystal CR1 on the circuit diagram is unreadable, but you should be able to read it off the crystal itself (Normally, crystals have their operating frequency marked on them). Edit: Ah, actually having now looked at your recent photos I see that it is a 6MHz crystal.

What frequency do you see on IC 8B (6504) pin 27?

Immediately after you switch the unit on, what state or activity do you see on IC 7A pin 10?

ScottishColin · 17th Aug 2023, 5:22 pm

The printer mechanism is an Epson 3110 - their tech reference manual is here which includes details of the other PCB:

https://archive.org/download/commodo...del%203110.pdf

Colin.

SiriusHardware · 17th Aug 2023, 5:25 pm

Quote:

No activity at all on pin 10 of 7A - no waveform, no voltage, no frequency.

Whenever you see no activity, always remember to say what state you see instead.

I'm actually expecting it to be in one state for a very short time after switch-on, then to see it change to the opposite state shortly afterwards. Are you seeing that?

The circuit formed by those two gates of IC 7A is the power-on reset circuit, it does the same job as UD16 in the PET you have just been working on.

SiriusHardware · 17th Aug 2023, 5:29 pm

Re: #13, what a great manual that is - only seems to describe the mechanical side of the printer but does it really, really well. Let's hope we don't need it though.

ScottishColin · 17th Aug 2023, 5:31 pm

Pin 10 of 7A is exactly the same after power on as it is in a powered off state. No change.

Colin.

Quote:

Originally Posted by SiriusHardware

Quote:

No activity at all on pin 10 of 7A - no waveform, no voltage, no frequency.

Whenever you see no activity, always remember to say what state you see instead.

I'm actually expecting it to be in one state for a very short time after switch-on, then to see it change to the opposite state shortly afterwards. Are you seeing that?

The circuit formed by those two gates of IC 7A is the power-on reset circuit, it does the same job as UD16 in the PET you have just been working on.

SiriusHardware · 17th Aug 2023, 5:34 pm

And...

...what state is it in please, when the power is on?

(High, or Low?)

ScottishColin · 17th Aug 2023, 5:44 pm

A picture tells a thousand words (I hope). Here's two as I'm not really sure how to answer the question - apologies.

Colin.

Quote:

Originally Posted by SiriusHardware

And...

...what state is it in please, when the power is on?

(High, or Low?)

SiriusHardware · 17th Aug 2023, 5:47 pm

So, Low.

I'll let you do a bit of thinking as my tea is imminent.

Where does the signal from 7A / (10) go to?

What state does that line need to be in, High, or Low, in order for the system to run?

ScottishColin · 17th Aug 2023, 5:54 pm

OK - that's the RESET pin of the 6504 which I believe needs to go low for a short period of time and then go high.

Is that right?

Colin.

17th Aug 2023, 1:49 pm	#2
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,089	Re: Commodore 3022 Printer If there are mechanical issues then I think TonyDuell is going to be your man here, but:- First thing I notice on the diagram is that there is a 'case closed' switch which presumably detects when the lid is open. Quite often, printers won't move or do anything while the lid is open or while they THINK the lid is open, so check that the switch is operating in the expected manner. What happens if you try to invoke the self-diagnostic test? Starting with power off, press and hold down line feed, and while doing so, turn the power on? (Have some paper loaded in case it does do something).

17th Aug 2023, 2:38 pm	#3
ScottishColin Octode Join Date: May 2012 Location: Perth, Scotland Posts: 1,604	Re: Commodore 3022 Printer No self-test activity after putting it all back together. I couldn't see any switches near the case anywhere fyi. It's worth noting that this printer is a 3022. I have linked to the 2022 manual as 1) I cannot find for love nor money any 3022 manuals and 2) I've been told that the 3022 and the 2022 are UK (European?) and US versions of the same device I don't know that this is true, but it's all I have right now. Also worth noting that I'm a little confused by the schematics in that document but that my motherboard is on page 19. Colin.

17th Aug 2023, 3:45 pm	#5
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,089	Re: Commodore 3022 Printer The mainboard being the same is a good start. You say you have checked the supplies (including the +24V/25V supply?). I'll take your word for that and move on. With very little in the way of expected activity, try approaching it as you would any other microprocessor system. Is it easy to get at the mainboard to make measurements from it while the power is on?

17th Aug 2023, 3:53 pm	#6
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,089	Re: Commodore 3022 Printer Ref: #4, there is a link in the first post which takes you to yet another possible circuit diagram. I think the first thing is going to have to be working out which of those available corresponds to your PCB. If you think your PCB (and by the way, how many PCBs are there in the machine?) corresponds to the layout in the first manual you linked to then there is a good chance one of the diagrams in that manual does too.

17th Aug 2023, 4:03 pm	#7
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,089	Re: Commodore 3022 Printer If you can get to the mainboard while power is on, try measuring the frequencies on: IC 3C pin 1 (8MHz?) IC 3C pin 12 (500KHz?) IC 3C pin 14 (1MHz?) This is to establish whether your PCB does or does not correspond to one of the circuit diagrams. Remember to use a significantly higher scope sampling frequency than the expected frequencies when looking at these pins.

17th Aug 2023, 1:26 pm	#1
ScottishColin Octode Join Date: May 2012 Location: Perth, Scotland Posts: 1,604	Commodore 3022 Printer Onto the next thing. I've cleaned this all up and checked the voltages and they look good. I've freed up all the mechanical bits and they move smoothly. What's supposed to happen at powerup is that the carriage homes itself. Also, tere is a feed button on the front which when pressed lights the LED next to it but no feed occurs. Anyone care to help get me started on this one? Anyone fixed up any old printers? TIA. Colin. https://archive.org/download/commodo...ce%20Guide.pdf

17th Aug 2023, 3:42 pm	#4
ScottishColin Octode Join Date: May 2012 Location: Perth, Scotland Posts: 1,604	Re: Commodore 3022 Printer Here's the only other (inconclusive) thread I can find about a 3022. https://forum.vcfed.org/index.php?th...-defect.57211/ Colin.

17th Aug 2023, 4:47 pm	#9
ScottishColin Octode Join Date: May 2012 Location: Perth, Scotland Posts: 1,604	Re: Commodore 3022 Printer Sampled at 48Mhz setting: IC 3C pin 1 - 6MHz IC 3C pin 12 - 500KHz IC 3C pin 14 - 1MHz Colin.

17th Aug 2023, 5:02 pm	#10
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,089	Re: Commodore 3022 Printer Not a bad start - the MHz value on Crystal CR1 on the circuit diagram is unreadable, but you should be able to read it off the crystal itself (Normally, crystals have their operating frequency marked on them). Edit: Ah, actually having now looked at your recent photos I see that it is a 6MHz crystal. What frequency do you see on IC 8B (6504) pin 27? Immediately after you switch the unit on, what state or activity do you see on IC 7A pin 10?

17th Aug 2023, 5:13 pm	#11
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,089	Re: Commodore 3022 Printer Regarding the other half hidden PCB, I see at least half a dozen transistors on there so I think that is going to be the motor control PCB, which corresponds to PDF page 20 of the manual you originally linked to. At the moment I am going on the assumption that pages 18-21 (sheets 1-4 of 4) are the diagrams which are relevant to your version.

17th Aug 2023, 5:22 pm	#13
ScottishColin Octode Join Date: May 2012 Location: Perth, Scotland Posts: 1,604	Re: Commodore 3022 Printer The printer mechanism is an Epson 3110 - their tech reference manual is here which includes details of the other PCB: https://archive.org/download/commodo...del%203110.pdf Colin.

17th Aug 2023, 5:29 pm	#15
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,089	Re: Commodore 3022 Printer Re: #13, what a great manual that is - only seems to describe the mechanical side of the printer but does it really, really well. Let's hope we don't need it though.

17th Aug 2023, 5:34 pm	#17
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,089	Re: Commodore 3022 Printer And... ...what state is it in please, when the power is on? (High, or Low?)

17th Aug 2023, 5:47 pm	#19
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,089	Re: Commodore 3022 Printer So, Low. I'll let you do a bit of thinking as my tea is imminent. Where does the signal from 7A / (10) go to? What state does that line need to be in, High, or Low, in order for the system to run?

17th Aug 2023, 5:54 pm	#20
ScottishColin Octode Join Date: May 2012 Location: Perth, Scotland Posts: 1,604	Re: Commodore 3022 Printer OK - that's the RESET pin of the 6504 which I believe needs to go low for a short period of time and then go high. Is that right? Colin.