Author Topic: 6128 very nearly alive  (Read 1214 times)

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Offline geeb

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6128 very nearly alive
« on: 01:25, 17 December 17 »
Hi

I read with some interest last night about cleaning the power switch which set me thinking about having a go with a 6128 that has been busted for a very long time. I was partly successful and have made this picture blog of how far I got. The problem now, having successfully got the machine to fire up is getting the drive working again. That is where my challenge is at a halt. I am thinking it's a locked up drive motor or busted one.

All help appreciated. Here is a picture post of the efforts thus far.

http://www.scuzzscink.com/amiga/scuzzblog_december17/scuzzblogddecember17_1601.htm

scuzz

Offline tjohnson

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Re: 6128 very nearly alive
« Reply #1 on: 11:12, 17 December 17 »
Hi

I read with some interest last night about cleaning the power switch which set me thinking about having a go with a 6128 that has been busted for a very long time. I was partly successful and have made this picture blog of how far I got. The problem now, having successfully got the machine to fire up is getting the drive working again. That is where my challenge is at a halt. I am thinking it's a locked up drive motor or busted one.

All help appreciated. Here is a picture post of the efforts thus far.

http://www.scuzzscink.com/amiga/scuzzblog_december17/scuzzblogddecember17_1601.htm

scuzz
Hi, is that a disk missing error you are getting?  That would appear to be that the drive isn't recognising the disk is inserted.  There is some kind of sensor mechanism for that, i think it varies between an optical mechanism and a mechanical one depending on the drive.   i would assume that it just sends a high or low signal to the controller chip upon sending a disk is inserted.

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Offline geeb

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Re: 6128 very nearly alive
« Reply #2 on: 16:25, 17 December 17 »
Interesting. Thing is there is no drive activity so I assumed the motor wasn't kicking in. I'll have a nose around and see what else I can find out about that. Thanks.

The disk is from a working 6128 and so there shouldn't be a problem with it.

scuzz
http://www.scuzzscink.com/amiga/a_amiga_inframe.htm

Offline tjohnson

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Re: 6128 very nearly alive
« Reply #3 on: 18:52, 17 December 17 »
Interesting, does the drive spin, can you hear it whirring away when you type cat?  You do have 12v plugged in too as without it the drive won't operate and you get the symptoms you have.  I cant remember the internal connections but could you have disconnected the 12v header inside the machine  (im assuming it has a header somewhere)

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Offline geeb

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Re: 6128 very nearly alive
« Reply #4 on: 19:46, 17 December 17 »
No drive activity and the 12v is connected through the monitor. The drive power light is on but no drive activity or noise. Feels to me like the motor is locked up or broken. I recently repaired a drive on a PCW9512 and the unit gave out a mighty thump as is powered up after being idle for so long. This drive hasn't been used for ten years.

I'll look back inside again and strip down the drive and see if anything has come adrift.

Feels like the old Norwegian Blue [ Monty Python ]

Offline gerald

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Re: 6128 very nearly alive
« Reply #5 on: 20:11, 17 December 17 »
Can you check that you actually have 12V on the drive ?
The 12V from the monitor is controlled by a pair of transistors on the motherboard.

Offline tjohnson

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Re: 6128 very nearly alive
« Reply #6 on: 20:27, 17 December 17 »
No drive activity and the 12v is connected through the monitor. The drive power light is on but no drive activity or noise. Feels to me like the motor is locked up or broken. I recently repaired a drive on a PCW9512 and the unit gave out a mighty thump as is powered up after being idle for so long. This drive hasn't been used for ten years.

I'll look back inside again and strip down the drive and see if anything has come adrift.

Feels like the old Norwegian Blue [ Monty Python ]
The led light is from the 5v not the 12v even if the main spindle motor was jammed the head seek might still move.

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Offline geeb

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Re: 6128 very nearly alive
« Reply #7 on: 00:05, 18 December 17 »
The led light is from the 5v not the 12v even if the main spindle motor was jammed the head seek might still move.

Sent from my E5823 using Tapatalk

Well done and many thanks. When I put the belt in I didn't remove the second power to the circuit board as it was hidden by the side bracket holding the drive. So after your post I decided to take the thing apart and check the connector. As you hinted the connector was not connected. When I bought the computer it was dead in the water and has been sitting there collecting dust. After I read here about the power switch , only then did I strip the computer down and fit the belt. Why the previous owner removed the belt I can never know. But when he/she did they reconnected the one connector to the board but not the smaller one on the other side.

Suffice to say I reconnected the power and she worked first time. Just magical to see the computer back on its feet after all these years. A big thankyou and a big thankyou to the post about the power switch. I have captured the moments in pictures and include the link.

http://www.scuzzscink.com/amiga/scuzzblog_december17/scuzzblogddecember17_1704.htm

I'm so happy.

scuzz


Offline Vyper68

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Re: 6128 very nearly alive
« Reply #8 on: 14:24, 18 December 17 »
Hi,

I was amazed that just by cleaning those tiny little contacts inside the switch itself would result in a working CPC6128 but Bryce knows his onions. I wonder how many were scrapped when this is all it needed to fix them.
Paul Woakes - Genius & Programmer

Thank you for Mercenary Paul

Offline geeb

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Re: 6128 very nearly alive
« Reply #9 on: 21:59, 18 December 17 »
Hi,

I was amazed that just by cleaning those tiny little contacts inside the switch itself would result in a working CPC6128 but Bryce knows his onions. I wonder how many were scrapped when this is all it needed to fix them.

He certainly does. I have a dead CPC664 with the same symptoms and I am planning on checking out the switch. Fingers crossed.

scuzz

Offline Bryce

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Re: 6128 very nearly alive
« Reply #10 on: 09:38, 19 December 17 »
Hi geeb,
    they are really great hi-res pictures of the switch. I don't think we have any pics of this quality on the Wiki, maybe we can use them?
Glad you got your 6128 and drive working again, Christmas is saved! :D
While you are checking those drives, always check for dry solder joints on the drive PCB as well. The most common spots are the power connector socket and the sockets that connect the motors to the PCB. If there's any sign of cracks in the solder then re-flow them.

Bryce.

Offline geeb

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Re: 6128 very nearly alive
« Reply #11 on: 01:29, 20 December 17 »
Hi geeb,
    they are really great hi-res pictures of the switch. I don't think we have any pics of this quality on the Wiki, maybe we can use them?
Glad you got your 6128 and drive working again, Christmas is saved! :D
While you are checking those drives, always check for dry solder joints on the drive PCB as well. The most common spots are the power connector socket and the sockets that connect the motors to the PCB. If there's any sign of cracks in the solder then re-flow them.

Bryce.

Always happy for anyone to use images from the site if it keeps computers alive.

I was singing your praises again today as the same technique restored a CPC464 from the dead. Bit of a sad state this machine and I now have to fix the drive belt to the cassette.

http://www.scuzzscink.com/amiga/scuzzblog_december17/scuzzblogddecember17_1902.htm

I shall certainly check out the other tips you gave. I guess I now know why on some of the CPCs you hear a little elctrical discharge at the switch.

I was well on the way to checking out a 664 but lost the wires to the switch they just broke off when I was putting the switch back. This one had a good amount of oil in the switch. Need to solder the wires back. Sadly there seems only just enough wire to get to the switch. No doubt update when I get further along.

http://www.scuzzscink.com/amiga/scuzzblog_december17/scuzzblogddecember17_1901.htm

Many many thanks... cus of your advice we have two more working Amstrads. Hopefully more soon.

scuzz


Offline Bryce

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Re: 6128 very nearly alive
« Reply #12 on: 09:33, 20 December 17 »
Yes, I've been reading your blog and watching progress. For the cracks in the 464 case I'd recommend this stuff: https://www.ebay.de/itm/Tamiya-87003-Tamiya-Cement-Plastikkleber-40-ml-NEU/112622953980

Clean the surfaces, put a very thin layer of the "glue" into the crack and push together and wipe off the excess. It's a solvent so it's actually melting the plastics back together, but it won't cause discolouring like superglue would and it's as strong as the original plastic.

And by the way - Pedantic mode.... The third wire to the switch is a ground, not an earth.

Bryce.

Offline CraigsBar

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Re: 6128 very nearly alive
« Reply #13 on: 22:37, 20 December 17 »
Hi,

I was amazed that just by cleaning those tiny little contacts inside the switch itself would result in a working CPC6128 but Bryce knows his onions. I wonder how many were scrapped when this is all it needed to fix them.
I conducted open switch cleaning on Shaun's cpc 464 last Sunday. Much the same result. Clean contacts and all working. Also reserrected his tape counter with some cleaning, sanding down of the case and lubrication.

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Offline Vyper68

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Re: 6128 very nearly alive
« Reply #14 on: 07:31, 21 December 17 »
I conducted open switch cleaning on Shaun's cpc 464 last Sunday. Much the same result. Clean contacts and all working. Also reserrected his tape counter with some cleaning, sanding down of the case and lubrication.

Sent from my ONEPLUS 3t using Tapatalk

It's like i said, i would never have thought to actually take the power switch apart and do that. I was sceptical at the time but i thought what have i got to loose it's worth a shot, and then i flicked the switch and bingo a working 6128. I must have only taken a few microns off the contacts it just seems amazing such a small detail can have such a dramatic effect.
Paul Woakes - Genius & Programmer

Thank you for Mercenary Paul

Offline Bryce

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Re: 6128 very nearly alive
« Reply #15 on: 13:05, 23 December 17 »
Yes, but they are non-conducting microns :)

Bryce.

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Offline geeb

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Re: 6128 very nearly alive
« Reply #16 on: 18:21, 24 December 17 »
Funny how stuff just comes around. I had kinda given up on an Amstrad Notebook I have with an empty screen. Then yesterday I was trying to get another Notebook working and this too had an empty screen and no power. I then replaced the 2032 in yet another Notebook that was working and I got an error saying the new battery was low on power and I should replace it. Anyway following the discussion here I decided to clean the battery contact and like magic it sprang back into life. So I then did the same with the other and that too worked fine. So I then moved to the busted Notebook and like magic it also sprang into life. Anyway charged with success I had a go at a TRS-80 Pocket with four batteries that was dead and it too worked. Also cleaned up an Acorn Pocket Book the same way.

So if you have any old computers that appear to be dead I would suggest checking the switch or battery connections first. Seems to be the main cause of issue for me.

Thanks for that.

By the way the CPC464 worked with the cassette drive rubber replaced. Was more the heads needing cleaning in truth.

http://www.scuzzscink.com/amiga/scuzzblog_december17/scuzzblogddecember17_2301.htm

scuzz

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Re: 6128 very nearly alive
« Reply #17 on: 11:29, 12 January 18 »
I kind of collect old calculators and you would be amazed to see how many are listed as "for parts or not working" on e-bay due to battery compartment problems  :D

Offline Vyper68

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Re: 6128 very nearly alive
« Reply #18 on: 12:02, 12 January 18 »
I kind of collect old calculators and you would be amazed to see how many are listed as "for parts or not working" on e-bay due to battery compartment problems  :D

Off-Topic:
I still have my Casio FX-100 that was given to me by my Father for my 13th Birthday when i started my 'O' Level Maths course in '81
Paul Woakes - Genius & Programmer

Thank you for Mercenary Paul

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Re: 6128 very nearly alive
« Reply #19 on: 16:47, 12 January 18 »
Nice machine!  :) I tend to use VDF display calculators, I love it.  At work, for example, I use a Commodore GL-979D  :D

Offline Vyper68

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Re: 6128 very nearly alive
« Reply #20 on: 19:01, 12 January 18 »
Nice machine!  :) I tend to use VDF display calculators, I love it.  At work, for example, I use a Commodore GL-979D  :D

Off-Topic:
My Dad used to have an old Commodore calculator -something like this.
Paul Woakes - Genius & Programmer

Thank you for Mercenary Paul

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Re: 6128 very nearly alive
« Reply #21 on: 20:04, 12 January 18 »
Ah! That is a 886D, with LEDs, I have a few at home  :) . It is a very robust machine but goes through the batteries like crazy, probably due to the IC. You would expect the VDF models to be more power hungry but with very early models that is not always the case. Those were very nice, though, with the leds behind little magnifying glasses  :laugh: