Author Topic: dead pcw 8512  (Read 2175 times)

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Offline caver99

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dead pcw 8512
« on: 20:21, 26 August 20 »
i've been using my pcw 8152 for a few hours now playing with basic.
i downloaded some games on to my gotek and been trying them out then i loaded ace but when i went to reset the pcw i had to switch it off as
the normal reset didnt work, so i pressed the power button and turned it off then back on again, selected another image on my gotek and it loaded
as it should but the sceen didnt power back up
so i have a working system but no screen, the tube powers up at the rear on the neck but its dead.
any idea anyone what could be the cause.
i've not recapped anything yet but it seems to be on the hot side of the board as the low voltage side still works as the main pcw board is powering and running.

Offline P5ychoFox

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Re: dead pcw 8512
« Reply #1 on: 10:20, 27 August 20 »
It may be a power board issue but first I'd try re-inserting all the floppy cables and ensure the black ground cable is attached to the power board. I've had PCWs do weird things like this with a loose cable. That said, I have also had a power board die too.

Offline caver99

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Re: dead pcw 8512
« Reply #2 on: 14:03, 27 August 20 »
they have all been checked and removed and reinstalled but still the same and with checking it looks like the lopt might have given up the ghost as it has deat shorts which they shouldnt have as far as i can tell so looks like im buggered.
i ant find a replacement part anywhere or even an equivelent
or hopefully the STK7308 which you can get replacements for which i will test shortly
im so gutted now
« Last Edit: 14:16, 27 August 20 by caver99 »

Offline caver99

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Re: dead pcw 8512
« Reply #3 on: 14:28, 27 August 20 »
further checking it maybe the STK7308 as low reading on the transformer it feeds and c5005 is low
« Last Edit: 19:51, 27 August 20 by caver99 »

Offline caver99

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Re: dead pcw 8512
« Reply #4 on: 20:24, 03 September 20 »
ive replaced [size=0px]STK7308 but the screen is still dead.[/size]
[/size][size=0px]ive checked and double checked and even removed floppy cables including power so just power board and screen and main pcw board are connected.[/size]
[/size][size=0px]the heaters on back of screen power up but tube doesnt[/size]
[/size]

Offline Bryce

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Re: dead pcw 8512
« Reply #5 on: 20:58, 03 September 20 »
Can you feel any static charge on the surface of the screen? If not, the LOPT has failed.

Bryce.

Offline PCWPIP

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Re: dead pcw 8512
« Reply #6 on: 21:34, 09 November 20 »
There have been several attempts to consolise the PCW.  A hack exists to output to an external screen.
« Last Edit: 21:38, 09 November 20 by PCWPIP »

Offline JonB

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Re: dead pcw 8512
« Reply #7 on: 12:38, 16 November 20 »
A hack? Ha ha!

In this thread I explain to user radu14m how he can connect the PCW to a composite monitor using a video mixer I designed. The PCBs are tiny as can be seen, and are designed to plug directly onto the PCW's main board connector. Please review this thread - there are pictures of the board, how it is fitted to the PCW and of it working.

https://www.cpcwiki.eu/forum/nc100-nc200-pcw-pda600/pcw-wont-start-anymore/msg165254/#msg165254

I may be able to supply the bare board for you to build. Not sure I have any left. If not, however, I'll upload it to OSHPark and you can order a set of 3 for small money. Send me a PM if interested.

Cheers
JonB
« Last Edit: 12:44, 16 November 20 by JonB »

Offline robcfg

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Re: dead pcw 8512
« Reply #8 on: 14:33, 16 November 20 »

Offline PCWPIP

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Re: dead pcw 8512
« Reply #9 on: 00:30, 17 November 20 »
Perhaps 'hack' is the wrong word....'upgrade' is I think better?   ;D


If my monitor ever fails I would use one of these in a heartbeat.


Habi's board is rather impressive too.

Offline P5ychoFox

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Re: dead pcw 8512
« Reply #10 on: 20:28, 21 December 20 »
Can you feel any static charge on the surface of the screen? If not, the LOPT has failed.

Bryce.

I have an 8256 which has good fuses but no power, no static, no neck glow. Does this sound like a failed LOPT too? Thanks.

Offline Bryce

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Re: dead pcw 8512
« Reply #11 on: 20:59, 21 December 20 »
Is there any power on the PCB?

Bryce.

Offline P5ychoFox

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Re: dead pcw 8512
« Reply #12 on: 16:17, 22 December 20 »
Is there any power on the PCB?

Bryce.

I was just checking for any voltages when the computer came to life. It had been on for about a minute with no signs of life but then started up. I wonder if it's a capacitor issue and a minute's charging up is all it needed. It's ok for now but without regular use it'll probably go dead again.

Offline Bryce

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Re: dead pcw 8512
« Reply #13 on: 16:30, 22 December 20 »
More likely a dry joint or a dodgy connector.

Bryce.

Offline Sebastian Blanco

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Re: dead pcw 8512
« Reply #14 on: 20:02, 22 December 20 »
Converting the tiny board to run using any composite monitor was easyer than reparing my other dead 8256 at least for me.


https://www.cpcwiki.eu/forum/nc100-nc200-pcw-pda600/finally-got-my-spare-pcw-8256-board-installed-in-a-case/



https://ibb.co/Yh9gkzz

Offline P5ychoFox

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Re: dead pcw 8512
« Reply #15 on: 15:57, 27 December 20 »
Can you feel any static charge on the surface of the screen? If not, the LOPT has failed.

Bryce.

Thanks, this makes sense. I'll check all the joints, especially around high temperature components.

Offline P5ychoFox

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Re: dead pcw 8512
« Reply #16 on: 16:00, 27 December 20 »
Converting the tiny board to run using any composite monitor was easyer than reparing my other dead 8256 at least for me.


https://www.cpcwiki.eu/forum/nc100-nc200-pcw-pda600/finally-got-my-spare-pcw-8256-board-installed-in-a-case/



https://ibb.co/Yh9gkzz

Very nice solution. I did something similar a while back and put an 8256 with Gotek into a CPC 6128 case. It's on YouTube somewhere.