Today I finally got my device programmer working so I just modded my first of two Keithleys.
First I placed an extra black heatsink on U119 already on the before picture.
Then I removed the elco's.
I wanted to place also a heatsink on U126 but this would not fit , it would touch U119 and the elco in front of it.
So i made a custom small heatsink from 4mm aluminium, a 3mm tap in it, put a small thermal compound sticker on it to make the heat transfer better and screwed it with a 3mmx6mm conical screw.
Works for me.
Then I removed the I2C calibration eeprom U136. Read it out and copied it to a brand new chip, resoldered the new chip.
Replaced the OTP eprom's with firmware A05 with the SST 39F020A flash eproms with firmware A19 (thanks to TiN and his brilliant website
)
Recapped , i put the two elco's that are close to the voltage regulator a bit in an angle so there is more distance between them.
Then came the final moment, power on.
Beep..... A19 YES! Three errors
Oh no... couldn't write them down quickly enough but from memory one was 812.
Shock.... power off.. wait three seconds... power on.... A19... no errors uhhhhh
I do not get any errors any more, so is this normal after changing from A05 to A19 firmware you get this or whats up?
Anyway checked quickly with a 10V source if the calibration is still ok, and it is
Any advice, or close her up and start using it again?