Pet Rescue
Experienced Member
Hi all, well at last I bagged myself a 2001 chiclet model its a 2001-8 bs.
You guessed it it's a non working unit.
Upon turning on you get the dreaded garbage screen.
The board type is 320351 assy the newer one with the holes punched out and 4108 ceramic ram chips.
I first tested all the voltages +9v unregulated the -5v +5v +12v etc then reseated all of the chips but no joy.
I have a 4008 with the exact same board minus the punched holes. I in turn swapped the big chips one by one.
The 6502 was fine, as was the 6522, one 6520 was fine but the other one was faulty. Next I swapped the roms one
by one.
UD9 901465-03 Fine
UD8 901447-24 Fine
UD7 901465-02 Fine
UD6 901465-01 Fine
UD10 901447-10 Fine
I then used the MikeS's advice off this forum to use an NOP adaptor. (advice given on a previous 3032 repair)
I popped in the adaptor and went through all the address lines and they checked out fine.
The clock signals in and out were fine, the reset circuit worked fine low for a second then high.
RDY/NMI/IRQ all high. But noticed the sync was low.
Also noticed that the board had some previous work on UC3 and UE5. but they both looked fine.
Next I bit the bullet and swapped the 2114 static video rams after piggybacking did nothing.
The garbage altered but still no joy damn I hoped it was them.
Next I socketed all of the 4108 rams again after piggybacking with no joy.
Put in 8 X 4116's but still no joy.(they work the same as 4108's I believe.)
Right time to go over the simple things, I started with the 6502 to make sure the pins continuity
went through to the board. Well well well pin 33 had no continuity!! I pushed the leg of a resistor in to
clean up any corrosion in the hole and popped the 6502 back in and the continuity was back.
Turned on the computer and Yes!! Get in "Commodore basic 7167 bytes free!!"
I then to satisfy my curiosity, put back the two original 2114's and it still worked!!
So next I put back the ceramic 4108's back and get in!! they still worked, I really love using my heat gun to
replace chips as it hardly ever damages them.
So the moral of this story is get a heat gun they are ace and if you get a garbage screen you are really
best to check continuity on the sockets Big chips and ROM's.
As you may of read a previous post where I failed to repair a 3032 pet and it has always bugged me what
was wrong and that I didn't fix it.
I feel I've exorcised that demon by fixing the same board with the same fault.
Sorry for the Long post but I hope this helps others who have a similar fault.
You guessed it it's a non working unit.
Upon turning on you get the dreaded garbage screen.
The board type is 320351 assy the newer one with the holes punched out and 4108 ceramic ram chips.
I first tested all the voltages +9v unregulated the -5v +5v +12v etc then reseated all of the chips but no joy.
I have a 4008 with the exact same board minus the punched holes. I in turn swapped the big chips one by one.
The 6502 was fine, as was the 6522, one 6520 was fine but the other one was faulty. Next I swapped the roms one
by one.
UD9 901465-03 Fine
UD8 901447-24 Fine
UD7 901465-02 Fine
UD6 901465-01 Fine
UD10 901447-10 Fine
I then used the MikeS's advice off this forum to use an NOP adaptor. (advice given on a previous 3032 repair)
I popped in the adaptor and went through all the address lines and they checked out fine.
The clock signals in and out were fine, the reset circuit worked fine low for a second then high.
RDY/NMI/IRQ all high. But noticed the sync was low.
Also noticed that the board had some previous work on UC3 and UE5. but they both looked fine.
Next I bit the bullet and swapped the 2114 static video rams after piggybacking did nothing.
The garbage altered but still no joy damn I hoped it was them.
Next I socketed all of the 4108 rams again after piggybacking with no joy.
Put in 8 X 4116's but still no joy.(they work the same as 4108's I believe.)
Right time to go over the simple things, I started with the 6502 to make sure the pins continuity
went through to the board. Well well well pin 33 had no continuity!! I pushed the leg of a resistor in to
clean up any corrosion in the hole and popped the 6502 back in and the continuity was back.
Turned on the computer and Yes!! Get in "Commodore basic 7167 bytes free!!"
I then to satisfy my curiosity, put back the two original 2114's and it still worked!!
So next I put back the ceramic 4108's back and get in!! they still worked, I really love using my heat gun to
replace chips as it hardly ever damages them.
So the moral of this story is get a heat gun they are ace and if you get a garbage screen you are really
best to check continuity on the sockets Big chips and ROM's.
As you may of read a previous post where I failed to repair a 3032 pet and it has always bugged me what
was wrong and that I didn't fix it.
I feel I've exorcised that demon by fixing the same board with the same fault.
Sorry for the Long post but I hope this helps others who have a similar fault.