Missing PAL16L8 on the board Jaleco City Connection

[r67055]

Just making sure you have tested all the components leading to that pal? also the ones its connected too? and the socket? If so i will need to take a look at mine when I have the time and see how the sync circuit works

I tried to draw what the situation is there.

 

[Monstermug]

I tried to draw what the situation is there.

So which ones if those connections looks suspicious under a scope?

 

[r67055]

So which ones if those connections looks suspicious under a scope?

Unfortunately, I don't have an oscilloscope. how many Mhz oscilloscope would I need to look at it?

 

[Monstermug]

Use a scope for now

 

[r67055]

unfortunately I do not have an oscilloscope

 

[Monstermug]

Probe i meant. U gonna have to get the databook out for all those ic in that circuit u drawn. Or buy a slice unit which does the legwork for u.

 

[r67055]

Probe i meant. U gonna have to get the databook out for all those ic in that circuit u drawn. Or buy a slice unit which does the legwork for u.

I took out all the ttl ic that has to do with the actual GAL.. I checked it based on the functions of the eprom burner ttl test. all are fine

 

[Monstermug]

I would personally probe them in circuit to see if i/o have signals on them. Chips make pass but if they arent being activated it can help u find the fault

 

[r67055]

I would personally probe them in circuit to see if i/o have signals on them. Chips make pass but if they arent being activated it can help u find the fault

on the i/o pins of which chip?

 

[Monstermug]

The ones connected. Check if they working normally against datasheet with a probe

 

[r67055]

The ones connected. Check if they working normally against datasheet with a probe

I will try to do it well. if I get stuck on something, I'll ask. Thanks.

 

[r67055]

Use a scope for now

I made a video about the sync signal

View: https://youtube.com/shorts/DuG0Wex0vwA?si=cmUdLFthP67MRH3w