That is exactly the function of the relay, and much joy has been had in the past with giving it a tap. I've also found in the past with my machines that powering the unit up and getting the blocks then doing a fast power off and back on often resolved this issue, at least for the moment. (I have to do something similar with my Matrix 6r)
Sent from my HAL 9000 in transit to Jupiter
toggle quoted message
Show quoted text
-----Original Message-----
From:
[email protected] [mailto:
[email protected]] On Behalf Of Frank D via groups.io
Sent: Monday, January 25, 2021 10:47 PM
To:
[email protected]Subject: Re: [K1000-K1200] 1000PX - not booting
OK, I went back in...
The 4.3vdc readings at the power supply are present when the PS is connected to the motherboard. If I pull the Molex connector from J4, 5vdc is present at the same pins. Seems that the power supply works correctly when not connected.
Looking at the PS schematic from k1000.net, I can not see any reference to pins 9 and 10. The rest of it is a bit hard to read. I also found a small AC voltage present at pin 9. 4.3 v is reaching the CPU at pin 14.
Here's what I have at the connector:
Pin# - VDC disconnected - VDC connected
1. gnd gnd
2. gnd gnd
3. +5 +4.3
4. +12 +12
5. -12 -12
6. -0.5 0
7. +5 +5 (backup)
8. +5 +4.3
9. +1.9 (2.2vac) +1.2 (1.5vac)
10. +5 +4.3
If anyone can interpret this or give any suggestions, I would truly appreciate it. Many thanks!
P.S. I'm also curious about the relay which Nicole mentioned. Seems like its function is to prevent a pop on the outputs during power-up. In any case, I do not hear it click. Is that a clue? ;-)
--
peace,
Frank Dickinson
90 East Productions
Our "lockdown" videos <>
