Recent content by makkuss2000

yes the bad LM317 went me far from solution because it worked without tube on…but it went bad (dropping voltage) when i connected the tube on board just to see if i saw something changed on the screen.. unbelievable! Thats mean that when you need to repair the analogic board.. everithing should...

Hello… finally..i Resolved! it was a bad LM317…it seems to work but the voltage, from one side was correctly 38v but to other side, only when i plugged the crt monitor (i worked to resolved this case without plug the crt monitir) strangely went down under 20v (and not 30 or more as needeed...

Hello to all, i tryed many approuch and controll on this board but what i suspect is that if i take a look on the wave and voltage (by oscilloscope) of a good Analogic board and on the wave and voltage of the AB that i’m tryng to repair, what i discovered is that there is a big difference of...

There is a problem on pin 3 (if figure 2 is referred on pin3). You should have a different frequency and a different wave too (60.15 hz). Did you still changed the TEA ic?

This is the wave on pin 1 of a working Analogic Board

On pin3 you should have this wave:

Hello, this is what i get from pin4 on a good Analogical board that i use the check the difference: If i see yours is like mine

Hello, sorry for delay, i just make same pictures from my osciloscope of my Analogic Board (with my Logical board connected that i tested that work perfectly). These are signal that i got from the BD1 plug starting from pin1 to pin 4. As showed on pin1 i have 22.25Khz, nothing on pin 2 (ground)...

Maybe my oscilloscope it has problem to show a 60hz wave (my model is mustool 8208) but 22khz is showed very well

However, i tested my logic board with anouther mac classic AB and it work perfectly.. so it’s a problem of this Analogical Board and i would like to repair it

Hello.. no signal at HS1

Hello, try to control the IP2 “LM317” and if it’s good maybe it’s C11 cap 220mf/50v gone

Hello to everyone, after recapped my Mac Classic (Analogic Board and Logic Board), everything was working really good but after 10 minutes i got an Horizontal line (picture1) Before this thing happend, i heared a strange and little noise came from analogic board like a buzz but i didn't gave...

yes mac classic

Hello to everyone, i'm having a strange problem on voltage for TDA4605... when i measure the voltate in AC on pin 6, the value go up and down from 10 to 20 and from 20 to 10 so it's not stable.... in fact after boot the mac, on screen gave me an horizontal line..... I changed this IC (TDA4605...