Amstrad 464 plus (no video output)

[elBeton]

Hi,
I have problem with Amstrad 464 Plus bought on ebay.
After power connection there were no signs of action (no led, no video).
I found a problem with the switch plug connector and I fixed this, now the LED is on, tape deck is working at least rewinding the tape. After pressing play motor is working, tape is moving (I'm not sure if it's supposed to work like this or after entering the run" command ?!).

But my main problem now is no video output so I don't know it is working or not.

First I checked input voltage on power plug there is 5V (I have power supply from jbl speaker 2,5A) but I checked also voltage on CPU and on pin 11 there is only 3.13V, on RAM there is 4,6V.

The CPU should probably have a voltage of 5V.
I want to chceck also CLK pin 6 on CPU and there is something I don't get it. On oscilloscope I have 757 Hz on it but on other cheaper multimeter I have 3,998 MHz on CLK pin 6 (?!).

Should I immediately replace the capacitors in the power supply area?
Any idea what I should check and do next or what is wrong at that point?

[andycadley]

I'm assuming you actually have tried with a cartridge in the machine? A Plus won't do anything without one.

[elBeton]

I don't get any cartridge with this computer. Really should I have it to get any video output?? So for what is a tapedeck??

[Deevee]

I don't get any cartridge with this computer. Really should I have it to get any video output?? So for what is a tapedeck??

Yes. The computer boots its firmware and OS from the cartridge. Without one, nothing in the computer will be initialised. Including the chip that generate video signal.

[McArti0]

Remove z80 and check pin11 again.

[eto]

So for what is a tapedeck??

Once the 464plus boots from cartridge ROM, you can use the tapedeck. 

Where are you located?

[elBeton]

Ok, I'll wait until the cart "Burnin' Rubber" I bought on ebay arrives. 
Thanks for that info I didn't know that.  

I have also an Amstrad CPC 464 and I thought they start similarly, I didn't know that the plus model had to have a card to start and get any video output.

Once the 464plus boots from cartridge ROM, you can use the tapedeck. 
Where are you located?

To run the tapedeck I need to have a basic rom on the cart, right?
I'm from Częstochowa in Poland.

[McArti0]

To zapytaj kogoś o pomoc na forum:
https://www.speccy.pl/forum/index.php?board=20.0

[eto]

To run the tapedeck I need to have a basic rom on the cart, right?

do you have an Eprom burner? If yes you can also create your own cartridges. There are quite a few PCB designs. All you need is an Eprom of the right size (128K for the original firmware), a cheap logic IC and 2 capacitors. 

[McArti0]

on the oscilloscope you have a long time base set at 2ms/div. set manual 1us or 100ns. Fnirsi has very stupid software.

[Anthony Flack]

Ok, I'll wait until the cart "Burnin' Rubber" I bought on ebay arrives.

Furthermore, I hope you got the one with the yellow top that says "Burnin' Rubber & Locomotive BASIC", which is the cart that should have come with your Plus machine, and not the one that came with the GX4000 console with the orange top that just says "Burnin' Rubber". 

If you got the orange one it will work, and you will be able to see if your Plus machine boots up at least, but you'll only be able to play Burnin' Rubber. 

[elBeton]

do you have an Eprom burner? If yes you can also create your own cartridges. There are quite a few PCB designs. All you need is an Eprom of the right size (128K for the original firmware), a cheap logic IC and 2 capacitors.

Yes I have T56_TL866II I will be making my own cart, but I'm waiting for the PCB's to arrive.

Furthermore, I hope you got the one with the yellow top that says "Burnin' Rubber & Locomotive BASIC", which is the cart that should have come with your Plus machine, and not the one that came with the GX4000 console with the orange top that just says "Burnin' Rubber".

If you got the orange one it will work, and you will be able to see if your Plus machine boots up at least, but you'll only be able to play Burnin' Rubber.

Unfortunately, I bought a red/orange one without basic (I have never seen yellow/blue/green ones on sale) but I will program it with my own rom.

[darkhalf]

Congrats on your 464 plus. Had the same thing happen (purchase from ebay, green screen and then waiting for the cart to arrive!)

I've put some info together on testing this and upgrading which should come in use once you get everything working
https://www.cpcwiki.eu/forum/amstrad-cpc-hardware/cpc464-build-thread/

[elBeton]

Congrats on your 464 plus. Had the same thing happen (purchase from ebay, green screen and then waiting for the cart to arrive!)

...

I have orange/red screen without any cart. I hope it works even though I have a different color on the screen.

[andycadley]

Congrats on your 464 plus. Had the same thing happen (purchase from ebay, green screen and then waiting for the cart to arrive!)

...

I have orange/red screen without any cart. I hope it works even though I have a different color on the screen.

Yeah, that looks like the kind of thing you get from a working Plus with no cartridge in it IIRC. Which is no guarantee of course, but not something to be concerned about.

[elBeton]

I already get my cart from ebay and everything is working fine My Amstrad 464 Plus is fully working Now time to RAM and DDI interface upgrades.
Thanks for Your support