I accidentally touched the unit's 9V supply voltage with my probe (GND I guess)
The screen works fine but measurements are broken, the display looks like the pic.
After a few (dead) seconds the trace jumps to the top of the screen and stays there, voltage reading usually goes to 51V.
Here are my test readings on the analog board:
Input 9V
V+ 8.14
V- 0.63
AV+ 5.03
AV- 0.81
V- 0.63
V1 2.22
V2 4.43
V3 2.56
V4 3.43
Board No. PN 109-15001-00F
I ordered a replacement unit just in case but I hope it is repairable.
What ICs do I need to replace? U5 maybe?
Thank you
Pls HELP, fried my analog board...
Re: Pls HELP, fried my analog board...
The negative voltage was gone. Maybe U5. Was it hot?
Re: Pls HELP, fried my analog board...
It was burn-smelly after the incident, now not hot, when I turn the unit on.
Microscope revealed a burnt point, chip also puffed a little...
Microscope revealed a burnt point, chip also puffed a little...
Re: Pls HELP, fried my analog board...
Chip replaced now.
Values:
Input 9V
V+ 8.14
V- -7.76
AV+ 5.03
AV- -4.94
V- 0.63
V1 0
V2 0
V3 0
V4 1.62
Still not OK, but getting closer.
I see measurements going, just the trace was at the bottom. See Vavr and other values on the pic, in the negative region about 5 div level constantly.
Freq value not displaying, although I can get the trace triggered.
What's next? I bought all the chips that are on the analog board, so that I can replace whatever else needed.
Thanks for the reply
Values:
Input 9V
V+ 8.14
V- -7.76
AV+ 5.03
AV- -4.94
V- 0.63
V1 0
V2 0
V3 0
V4 1.62
Still not OK, but getting closer.
I see measurements going, just the trace was at the bottom. See Vavr and other values on the pic, in the negative region about 5 div level constantly.
Freq value not displaying, although I can get the trace triggered.
What's next? I bought all the chips that are on the analog board, so that I can replace whatever else needed.
Thanks for the reply
Re: Pls HELP, fried my analog board...
Double checked V4, it is positive instead of negative.
Also, when I probe V4 with the multimeter, the small red LED D1 lits up on the back of the digital board.
Also, when I probe V4 with the multimeter, the small red LED D1 lits up on the back of the digital board.
Re: Pls HELP, fried my analog board...
The voltages are good. V4 should be around +1.6V so your measurement is correct. Please set couple switch to ground and do VPos alignment and see it the trace goes to normal.
Re: Pls HELP, fried my analog board...
THANK YOU
Everything is back to normal
Now I'll have 2 units
Everything is back to normal
Now I'll have 2 units