I have some protective shields from C64 and Commodore Amiga. Do you think these shields are made of MU-metal?
I will try these . I'll be back with some new photos when the machine is perfect. :)
the light in the room is artificial.
It seems impossible to get the shakes on film. It's so small and fast. I could describe it as vibrations (tremors) that would occur if I were drilling with a drill.
I will open up the CRT and check as you suggest.
Ok guys! The Motorola MC6821 has arrived and the PET is fully alive! The keyboard works perfect! This is so cool! I finaly have a nice looking PET. And its working.
BUT its still not perfect. I have notice that the screen has some flickering. Its crystal clear but the picture shakes a bit...
Ok I finaly got the socond 7805 regulator. And you know what? It boots! Im so happy. A big step forward. 2 regulators was actually bad!
But now there is another problem. The keyboard dosent seems to work. The only key that work is "inst del".
The cursor is blinking and there is...
Ok ,thats good to know. This PET gonna live!
But its quite annoying that the regulator shuts down (if its not broken) becouse its makes it alot harder to find a faulty IC.
My bad Dave. I dident get it that it was a mix of diffrent Pets on the 2000N page.
I found a 5W 39ohm. But I guess thats to high value. I'll have another 7805 on the way. So I have to wait a couple of day before it arrives.
I have been checking all the small 0.1uf caps from the 5v line and all seems fine.
Whould a shorted 74xxx cause the regulator to shut...
I unfortunately I dont have any kind of these value resitors. But I'll do the Dave test again.
I report back.
And this test is fine! Right?
Close to 5V.
@daver2 Im getting a little confused. At the 2001N parts list C15 is a 10uf 25v tant cap. not a 1uf. Are u 100% sure this is the...
If the other regulator was killed by me. How can u then explain why the CPU had no voltage from the begining. Before I did any test at all? And when I changed the regulator I suddenly has 5v.
Yeah it could be low resistance as you say.
Can u please explain little more in detail how I should do this test. Im not sure exactly how to do this. Becouse it sounds like the test we did aka daves resistor test?
@daver2 I use the on you linked
Yeah I know they are polarized. There are a + mark on the motherboard 😉 And a regular cap would be fine right?
have been looking at the motherboard under a microscope for a couple of hours now and tested diffrent components for shorts. I found one short on C15 it,s a smal green cap. I think it is a 1000nf cap. Atleast my tester say so. I have not been able to verify this agains the schematic becouse I...
I have double checked the caps. Everything looks good there. There all in the right place and no shorts there. I have also clean the area with isopropanol.
I have no voltage on the 74Ls244 Vcc (pin 20) but I have 4v on pin 1 (1g)!? There is 4 of these chips. The 2 below 7508 has these...
@daver2 @Hugo Holden @SiriusHardware
Ok guys! The 7508 voltage regulator has arrived! And I got news for you! The old regulator was indeed shooted. The CPU now gives me 5V. But the reset signal stays high.
I still have a black screen. BUT when i turn of the computer I see a green flash. So the...