Pictures of 48k ZX Spectrums Showing the Important Voltages

1024MAK

Pictures of 48k ZX Spectrums Showing the Important Voltages

First, a issue two board:

(click for the full size picture showing the details clearly)

Connect the negative (black) lead to the metal heat sink for all of these voltage tests.

• The +5V should be between +4.75V and +5.25V
• The +9V should be between +8V and +12V
• The +12V (for the "lower" 4116 16k RAM chips, bottom left of the board) should be between +11V and +13V
• The +12V (for the LM1889N colour encoder chip) should be between +10.8V and +13V
• The -5V should be between -4V and -5.5V

Mark

Note to moderator, it would be good if this was made a sticky :D
I will add some other issue boards next week.

TheTurnipKing

Issue 6 would be appreciated. I have a board showing some weirdness.

dreamscape

Very helpful indeed! Thank you!

Should be a sticky imo

schombi

That?s handy! Thanks for posting.