Some Faulty CPC6128 Faults ( Info Only )

[Audronic]

Hi All

This is just for Information.

Over the last couple of weeks i had 2 Easy Faults on CPC6128's

1) The Z80 Was Unwell, Replaced.                   Now the Unit works well. Screen Displayed Nothing, Temperatures on chips were all Normal (Cold)

2) The 16 MHz Crystal did not work, Replaced. Now the unit works well. Screen Displayed Nothing, Temperatures on chips were all Normal (Cold)

If anybody else has Hardware problems or Fixes Please Post,  as it helps Others with Hardware problems that may have.


@Bryce
I have replaced the IC 117 from a 74HCU04 with a 74HC04 (Clock) do you think that this is Suitable ??


Thanks

Ray



PS:- Added Screen and Temperature Info.

[VincentGR]

Should be pinned!

[ASiC]

Hi Ray,


Can you remember what the CPC was displaying on each case before the fix please?
It could help other people troubleshooting similar faults.


From what I recall, when my cpc had a blown RAM, I was getting a black border with a grey screen (or was it a green screen?).


It could also help if you've noticed any unusual heat coming off the dodgy components.


Cheers

[Audronic]

@ASiC




I will add screen display and temperature info in first post.
Thanks for the Thought


Ray

[Bryce]

The 74HCU04 is an unbuffered version of the HC04. It is specifically designed for use in oscillator circuits. The HC04 may work, but it's not guaranteed to work as the buffer may disrupt oscillation. I would swap it for a proper HCU part when you can.

@ASiC: The problem with lists of: "Computer showed X, problem was Y" is that they are not certain. A grey box with a green border could be a RAM problem, but it could also be a CPU problem, a logic problem or many other things. It is better to understand what's happening than blindly following a list. Following lists like that usually result in many components being needlessly replaced.

Bryce.

[Audronic]

@Bryce


Ok Thanks


Ray

[Audronic]

@All


Picked up an other CPC6128 yesterday (Unknown condition)(Not tested)
Powered it up :- No Light - Nothing
Problem :- Power Switch Open circuit, Dismantled Cleaned contacts,
Power up The unit works.
|A Drive not ready.
Replaced belt.
Thats it for an untested CPC 6128 it now works very well.


Ray