Issue 6 board updates

[Popopo]

And now...
After getting axial capacitors, sockets for RAM and xtal X1 from China... long wait
I got a new doubt...
Often there are some thumbs on boards for oscillators or xtals that have a pin for GND... well... it happens to me that in some ZX boards when I connected them to this pin the system stop working, also in Commodore Amiga 500, so I shouldn't connect those Xtals to GND... but here we go... Issue6 replica had this pin connected to GND and I have no idea if I should connect the chassis to GND or not...
Here is a picture to illustrate the question:



Should I connect chassis to GND?

[Popopo]

Hi everyone...
after trying to document about when should a chassis oscilator be connected to GND or not... I got the answer for this particular case...
The answer is... DO NOT CONNECT!!! anyway! never XD

They were careful about and placed a piece of plastic between the oscillator and GND as it is shown in my Issue 5 board.

[klausfrank]

Hi,
As promised, here are the corrections posted by Tony Firshman.

Corrections by Tony Firshman.pdf

(683.65 KiB) Downloaded 248 times

Regards Klaus

[Pr0f]

For the crystals - I use a small air gap and then a blob of silicon or glue just under it, but avoiding the pads for the 2 crystal contacts - or if I have spare ones - the plastic spacers.

It's a good idea to have the crystal mechanically solid on the pcb and not rely on the leads to support it on their own. It also stops any possibility of the crystal acting like a microphone.

[Derek_Stewart]

Hi,

A slight digress from the thread, but Tony Firshman has a Trouble Shooting Guide on his web site:

http://tfs.firshman.co.uk/ql/trouble.htm

This might be worth looking at.

[Popopo]

Hi,
As promised, here are the corrections posted by Tony Firshman.Corrections by Tony Firshman.pdf
Regards Klaus

Thank you very much!

[Popopo]

For the crystals - I use a small air gap and then a blob of silicon or glue just under it, but avoiding the pads for the 2 crystal contacts - or if I have spare ones - the plastic spacers.

It's a good idea to have the crystal mechanically solid on the pcb and not rely on the leads to support it on their own. It also stops any possibility of the crystal acting like a microphone.

Good idea...
plastic seems great, sometimes I use this layer that women use for nails. Do you know what I mean? with acetone that is easy to remove if needed. But... plastic... so nice and easy.

[klausfrank]

The pages from Tony Firshman about troubleshooting “ QL Troubleshooting “ are also in my version of QL Service Manual amongst others.
Regards Klaus

[Derek_Stewart]

Hi,

I have OCRed the QL Service Manual, inserted Martyn's Appendix D5.

I have to update all the diagrams, from scanned images and updatd the QL board layout and schematics for Board issues 5,6 by Silvester.

I have an Issue 7 QL, which would nice to update the manual with the update, but this is a bit of work.

Here is the perliminary version, I will update the in due course.

QLSM01.zip

QL Service Manual in PDF & ODT formats

(6.63 MiB) Downloaded 143 times

[pjw]

Hi,

I have OCRed the QL Service Manual, inserted Martyn's Appendix D5. <>

Good job, Derek. It looks great. Thank you!