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Vintage Computers Any vintage computer systems, calculators, video games etc., but with an emphasis on 1980s and earlier equipment.

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Old 3rd May 2024, 6:37 pm   #301
ScottishColin
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Default Re: Commodore 8026 printer / typewriter

It is a 327 on this board.

I'm struggling to read the capacitors though - they are going the same way as the others.

J1 is top left of the picture - 16 way connector with 4 pink, 4 yellow and 4 black. There's an extra connector on this board - on the right hand side of the main board with a black and purple cable. It looks at first sight that it comes from the PSU. There's also a connecting wire from the 39V point on the bottom right on the main board to the daughterboard (brown wire) which is not on the Commodore version.

Colin.


Quote:
Originally Posted by SiriusHardware View Post
The battery leak damage to the components just north of the batteries doesn't look quite as bad as on your original machine, so there's some hope that you might be able to read the number off what we've been calling the '327' to see what it actually is - also the values of those capacitors near the power input connector.

I notice there is indeed a serial UART IC (6850) just where Tony suggested there could be one.

Is the J1 connector you've been talking about the long black connector at the far left end of the upper edge of the PCB?
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Old 3rd May 2024, 7:09 pm   #302
SiriusHardware
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Default Re: Commodore 8026 printer / typewriter

Good to have the identity of the mysterious transistor confirmed once and for all, and a good call by all who suggested it might be a BC327. Shame about the caps but as originally said the value won't be too critical as long as they are appropriately voltage rated (which the ones you fitted in the other machine are).

If you were able to desolder one end of each of the different types of capacitors near the power input connector your new component tester box would tell you their values, but maybe wait until the desoldering iron arrives if you want to try that.

Quote:
J1 is top left of the picture - 16 way connector
OK, 16 way, and what pin spacing? Pull the connector off and line up one side of a larger DIP IC next to the pin row connector, is the pin spacing the same as the pin spacing on an IC?
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Old 3rd May 2024, 7:18 pm   #303
SiriusHardware
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Default Re: Commodore 8026 printer / typewriter

It occurs to me that if the J1 wiring loom is the same at both ends in both machines, you could 'borrow' the loom from this machine and fit it in the 8026 if you think the condition of the contacts looks any better.
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Old 3rd May 2024, 7:21 pm   #304
ScottishColin
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Default Re: Commodore 8026 printer / typewriter

This is a photo from the Commodore 8026 where I was playing with the idea of replacing the connector with individual DuPont connectors and soldering them to the wiring of the motor itself. I'd label them individually if I did this - hopefully that answers the question below.

Colin.

Quote:
Originally Posted by SiriusHardware View Post
Good to have the identity of the mysterious transistor confirmed once and for all, and a good call by all who suggested it might be a BC327. Shame about the caps but as originally said the value won't be too critical as long as they are appropriately voltage rated (which the ones you fitted in the other machine are).

If you were able to desolder one end of each of the different types of capacitors near the power input connector your new component tester box would tell you their values, but maybe wait until the desoldering iron arrives if you want to try that.

Quote:
J1 is top left of the picture - 16 way connector
OK, 16 way, and what pin spacing? Pull the connector off and line up one side of a larger DIP IC next to the pin row connector, is the pin spacing the same as the pin spacing on an IC?
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Old 3rd May 2024, 7:22 pm   #305
ScottishColin
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Default Re: Commodore 8026 printer / typewriter

Yes - that was my thought too. I'll check the state of the connector/contacts.

Colin.

Quote:
Originally Posted by SiriusHardware View Post
It occurs to me that if the J1 wiring loom is the same at both ends in both machines, you could 'borrow' the loom from this machine and fit it in the 8026 if you think the condition of the contacts looks any better.
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Old 3rd May 2024, 7:29 pm   #306
SiriusHardware
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Default Re: Commodore 8026 printer / typewriter

Re: #304, that suggests to me that they are 0.1" (2.54mm) pitch, which is one of the most common. Not long ago I could have instantly found you a polarised 16-way pin-row connector and a matching connector shell and crimp contacts but I don't think we have any left now.

I get the impression you are fairly determined to avoid having to change that connector pair so I guess you'll probably try swapping the cable loom, if possible, first.
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Old 3rd May 2024, 7:40 pm   #307
ScottishColin
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Default Re: Commodore 8026 printer / typewriter

The issue is that my confidence has decreased in my ability to desolder, particularly repeatedly, on these older boards.

My desoldering station has turned up but been whisked away from under my nose and given to my Mother-in-Law to give back to me on my birthday in 3 weeks or so. I'll try the other one first I think.

Colin.

Quote:
Originally Posted by SiriusHardware View Post
Re: #304, that suggests to me that they are 0.1" (2.54mm) pitch, which is one of the most common. Not long ago I could have instantly found you a polarised 16-way pin-row connector and a matching connector shell and crimp contacts but I don't think we have any left now.

I get the impression you are fairly determined to avoid having to change that connector pair so I guess you'll probably try swapping the cable loom, if possible, first.
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Old 3rd May 2024, 7:53 pm   #308
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Default Re: Commodore 8026 printer / typewriter

Its possible to get housings in multiples for dupont connectors, and you can release the contact from the singles and fit into the multiway connector so you don’t need a crimping tool.

https://www.aliexpress.com/item/1005006208001550.html
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Old 3rd May 2024, 9:24 pm   #309
ScottishColin
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Default Re: Commodore 8026 printer / typewriter

I've got a crimper and some 4/5/6/7 way housings which I can use.

I just need to stop prevaricating and make a decision...

Colin.

Quote:
Originally Posted by Mark1960 View Post
Its possible to get housings in multiples for dupont connectors, and you can release the contact from the singles and fit into the multiway connector so you don’t need a crimping tool.

https://www.aliexpress.com/item/1005006208001550.html
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Old 3rd May 2024, 9:48 pm   #310
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Default Re: Commodore 8026 printer / typewriter

As you are in the hitherto highly improbable position of possessing an identical(?) spare cable loom I would probably try that first, as long as you are sure it is wire-for wire, point-to-point identical to the one on the 8026 - bearing in mind that they are not identical devices.
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Old 4th May 2024, 2:29 am   #311
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Default Re: Commodore 8026 printer / typewriter

Quote:
Originally Posted by ScottishColin View Post
This is a photo from the Commodore 8026 where I was playing with the idea of replacing the connector with individual DuPont connectors and soldering them to the wiring of the motor itself. I'd label them individually if I did this - hopefully that answers the question below.

Colin.

Quote:
Originally Posted by SiriusHardware View Post
>>
>>
Quote:
J1 is top left of the picture - 16 way connector
OK, 16 way, and what pin spacing? Pull the connector off and line up one side of a larger DIP IC next to the pin row connector, is the pin spacing the same as the pin spacing on an IC?

Well the white connector on the photo attached to that (#304) post, has an unusual latching tab at the top of one of the long sides and is similar to those used in older TV's - but usually with a rather-larger pitch (particularly with ones on HV scan-coils)

It isn't clear if the 16w black J1 one is a similar one, especially with all those individual sockets inserted.
- Did you ever find any markings on the original 16way socket-housing?
A photo of that may be usefu to help identify it.
Plus taking a look at this useful website, to see if there's one that looks the same: https://www.mattmillman.com/info/crimpconnectors/
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Old 4th May 2024, 4:31 am   #312
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Default Re: Commodore 8026 printer / typewriter

Quote:
Originally Posted by ScottishColin View Post
There's an extra connector on this board - on the right hand side of the main board with a black and purple cable. It looks at first sight that it comes from the PSU.
Colin.
My guess is that that carries one or both of the +/-12V supplies for the RS232 driver. Or some voltage they could be produced from.
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Old 4th May 2024, 10:22 am   #313
ScottishColin
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Default Re: Commodore 8026 printer / typewriter

OK - photo attached of the two motors which are marked slightly differently, although the connectors/wiring are the same.

The left hand motor marked "2x380/0,236" is the original Commodore motor. The right hand motor marked "2x370/0,236" is the one from the Olympia printer.

I have plugged in the Olympia motor to the Commodore printer and attached all other connectors.

At power on, I get a short beep every time.

About 50% of the time, the motor in question is free, 50% of the time I get a small movement then it locks.

Colin.
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Old 4th May 2024, 11:26 am   #314
ScottishColin
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Default Re: Commodore 8026 printer / typewriter

Additionally, none of the keys produce any activity. Also moving the print carriage manually to the left still triggers the sensor correctly which then triggers the motor in question correctly.

Colin.
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Old 4th May 2024, 12:18 pm   #315
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Default Re: Commodore 8026 printer / typewriter

When you say 'triggers the motor in question correctly', what do you mean? The motor runs? The motor locks?
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Old 4th May 2024, 12:24 pm   #316
ScottishColin
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Default Re: Commodore 8026 printer / typewriter

The motor runs in a consistent direction until I move the carriage slightly to the right manually.

Colin.

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When you say 'triggers the motor in question correctly', what do you mean? The motor runs? The motor locks?
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Old 4th May 2024, 12:43 pm   #317
TonyDuell
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Default Re: Commodore 8026 printer / typewriter

Well, that means the motor driver transistors and the processor are all working, otherwise the motor could not turn.
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Old 4th May 2024, 1:12 pm   #318
ScottishColin
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Default Re: Commodore 8026 printer / typewriter

I assume it also means that the optical sensor on the small PCB on the carriage is working too, along with (at least some of) the cable connecting the carriage PCB to the main board.

Colin.
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Old 4th May 2024, 1:39 pm   #319
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Default Re: Commodore 8026 printer / typewriter

Yes, it must be detecting something.

Is this in the Commodore unit?

I think you need to repair that broken gear. Is there a good one in the Olympia typewriter that you could borrow. For a more permanent repair I'd probably get a gear of a suitable type (this was discussed many messages ago) and make a spindle/hub to put it on, but it is likely you'd need a lathe. You've suggested 3D printing, which may well be worth a try.
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Old 4th May 2024, 1:47 pm   #320
ScottishColin
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Default Re: Commodore 8026 printer / typewriter

It is the Commodore unit.

The 'new' Olymipa gear has the same problem sadly.

Right now, the motor connected to J1 is out of the printer so it is not affected by the broken gear but I agree, I need to make one.

Colin.

Quote:
Originally Posted by TonyDuell View Post
Yes, it must be detecting something.

Is this in the Commodore unit?

I think you need to repair that broken gear. Is there a good one in the Olympia typewriter that you could borrow. For a more permanent repair I'd probably get a gear of a suitable type (this was discussed many messages ago) and make a spindle/hub to put it on, but it is likely you'd need a lathe. You've suggested 3D printing, which may well be worth a try.
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