Atari Lynx 2 blank (black) screen

[Sylver]

Hi guys,

I have a problem and didn't find any obvious solution in any topic I have read for now !

First I got a Lynx II that was not powering on ! I replaced Q12, D13, Q7 and Q8. After that a press on the power button is lighting the power led, I see backlight on the screen but the screen is black and I hear a small pop sound in the loudspeaker, but nothing, no sound no color, just a black screen !

I then replaced all electrolytic capacitors as I know that they can cause some issues when getting old, but still the same behaviour

I know my game is ok, I did use it on a working Lynx 1 I have !

After reading some topics, I decided to replace the RAM chips ! I had to remove the shielding and the cartridge connector for that ! I took the ram chips from my Lynx 1 and proceed in an exchange ! The Lynx 1 is still working well with the RAMs from the Lynx 2 so that was not the problem

I installed the RAMs from the Lynx 1 on the Lynx 2, and I shorted pins 31 & 33 from the cartridge connector to simulate the presence of a cartridge to allow the console to power on (and to show me the no cartridge message if everything goes well). After that, just a black screen as previously ...

I also replaced the 16MHz quartz with no change !

I'm quite stuck now, I didn't find any chip getting hot when the console is "on". Could you give me some advices about what to check next ?

I have an oscilloscope at home also, so maybe there are some key signals to check to know if for example the Suzy or Mikey chips are dead (I hope not ...) or to found any responsible for this issue ?

Thanks for any help you can bring

[+karri]

One of the first things I do is to plug a stable 5V DC current to where it is supposed to be. Or alternatively confirm that the power is correct when the Lynx is on.

 

The next thing would be to find out if the clock works. Does the CPU try to boot. Check if address lines are changing. What about the data bus.

[rj1307]

If you have an oscilloscope, you can quickly check the waveforms, suggest this:

 

 

First check the waveforms on memory chips, if it will be "quiet" there, unfortunately Hayato is dead  
Of course you checked the power supply? What voltage do you have on the circuits?

[Sylver]

Thanks guys, I'll find where is my oscilloscope and I'll make some tests !

Thanks to your post rj1307, I've just noticed that my Lynx 2 has a Hayato chip and not a Mikey one, which means that I won't be able to take the chip from my Lynx 1 to test my Lynx 2 . Unless they are compatible after all, but according to data sheet they seems to have some differences regarding some pins ! Do anyone has an answer regarding this ?

In case it's confirmed to be a Hayato problem, are there some suppliers for this chip or will I have to put this board on a shelf maybe forever ?

Edited April 18, 2020 by Sylver

[+karri]

3 hours ago, Sylver said:

Thanks guys, I'll find where is my oscilloscope and I'll make some tests !

Thanks to your post rj1307, I've just noticed that my Lynx 2 has a Hayato chip and not a Mikey one, which means that I won't be able to take the chip from my Lynx 1 to test my Lynx 2 . Unless they are compatible after all, but according to data sheet they seems to have some differences regarding some pins ! Do anyone has an answer regarding this ?

In case it's confirmed to be a Hayato problem, are there some suppliers for this chip or will I have to put this board on a shelf maybe forever ?

I did order a lot of 5 Hayato chips from Ali Express. That was the minimun order so I have 4 extras in case you want one. (Once I get them. They are still in transit.)

[rj1307]

@Sylver, you can mount Mikey from Lynx I to Lynx II, the console will start, the screen will display content but with a lot of interference in the form of thin stripes. Also the sound will be strongly distorted. Nothing will break, you can do it for testing.

Hayato chips are also available at http://www.best-electronics-ca.com/custom-i.htm for $ 39, just be careful because they are badly described as "Lynx II Mikey C301719".

 

@karri, can you provide a link to these chips?

[+karri]

19 minutes ago, rj1307 said:

@Sylver, you can mount Mikey from Lynx I to Lynx II, the console will start, the screen will display content but with a lot of interference in the form of thin stripes. Also the sound will be strongly distorted. Nothing will break, you can do it for testing.

Hayato chips are also available at http://www.best-electronics-ca.com/custom-i.htm for $ 39, just be careful because they are badly described as "Lynx II Mikey C301719".

 

@karri, can you provide a link to these chips?

Suzy https://www.aliexpress.com/item/33021335303.html

Hayato https://www.aliexpress.com/item/4000874785428.html

[+-^CrossBow^-]

On 4/17/2020 at 11:46 AM, Sylver said:

Hi guys,

I have a problem and didn't find any obvious solution in any topic I have read for now !

First I got a Lynx II that was not powering on ! I replaced Q12, D13, Q7 and Q8. After that a press on the power button is lighting the power led, I see backlight on the screen but the screen is black and I hear a small pop sound in the loudspeaker, but nothing, no sound no color, just a black screen !

I then replaced all electrolytic capacitors as I know that they can cause some issues when getting old, but still the same behaviour

I know my game is ok, I did use it on a working Lynx 1 I have !

After reading some topics, I decided to replace the RAM chips ! I had to remove the shielding and the cartridge connector for that ! I took the ram chips from my Lynx 1 and proceed in an exchange ! The Lynx 1 is still working well with the RAMs from the Lynx 2 so that was not the problem

I installed the RAMs from the Lynx 1 on the Lynx 2, and I shorted pins 31 & 33 from the cartridge connector to simulate the presence of a cartridge to allow the console to power on (and to show me the no cartridge message if everything goes well). After that, just a black screen as previously ...

I also replaced the 16MHz quartz with no change !

I'm quite stuck now, I didn't find any chip getting hot when the console is "on". Could you give me some advices about what to check next ?

I have an oscilloscope at home also, so maybe there are some key signals to check to know if for example the Suzy or Mikey chips are dead (I hope not ...) or to found any responsible for this issue ?

Thanks for any help you can bring

In reading this...there is one thing I have to ask that is unique about the Lynx 2 vs the Lynx 1.

 

You did have a game inserted when powering it up correct? Because the Lynx 2 doesn't not normally display the Insert Game screen like the Model 1 does unless there is only partial contact being made with the game. Without a game, you get exactly what you described with a Lynx 2.

 

 

[Sylver]

Thanks you all for these valuable advices ! I did solder back the cartridge connector to be sure to have a complete cartridge connected as it seems to cause issues to only have pins 31 & 33 connected.

I've just tested the power circuit output (TP15) and it's 4.5v while it should be solid 4.9-5.0v I guess ?

Dunno if it's a real issue, but it won't help I guess ...

On the other signals, I see a 16MHz sinusoid at XTALO pin but CLK1/2/3 are just 4.5v DC ... X16M (pin 3) of suzy is also 16MHz ...

I have no activity on different data/address pins ...

 

Edit : I have 5.07v on TP15 on my Lynx 1 ... I'll check this point then !

Edit2 : I changed the diode to have the same than in my Lynx1 and I have now 5.1v on TP15 in my lynx 2, but same thing : nothing on any data/address bus ! I checked RESET/ of Hayato which is to 5.1v so it seems normal but there is still no life on address/data bus ...

It means that, @karri, you can sell me one of his Hayato chip I guess !

Could you tell me what will be the price without shipping (I'm in France so shipping should not be that expensive) ? 

Edited April 19, 2020 by Sylver

[Sylver]

waiting for replacement now ?

[+karri]

My guess is around €10 as I have to pay import tax and VAT for it. To France the postage is around €2 I think.

 

--- Plus a closer checking of Aliexpress site makes me wonder if they know what chips they are selling... Well, that remains to be seen.

[Sylver]

Ok great ! Please send me an PM so we can arrange everything for when you'll get them !

In France most of the time we don't have to pay import tax/VAT from stuff bought on aliexpress unless we use FEDEX/TNT/DHL/... Anything that comes with standard courrier will be taxless (even if it should be taxed, I think they are too lazy here to take care of all these small parcels with fake value declaration on them ...)

Edited April 19, 2020 by Sylver

[rj1307]

@karri, both links you provided lead to SUZY, are you sure you ordered Hayato?

 

@ - ^ CrossBow ^ -, I don't know if I understood correctly, but Lynx II with the 31/33 pins shorted will display "Insert Game".

 

Edited April 19, 2020 by rj1307

[+-^CrossBow^-]

9 minutes ago, rj1307 said:

@karri, both links you provided lead to SUZY, are you sure you ordered Hayato?

 

@ - ^ CrossBow ^ -, I don't know if I understood correctly, but Lynx II with the 31/33 pins shorted will display "Insert Game".

 

I missed that part and that is one me. The only other thing to note, is that most of the Lynx II units I've done McWill and similar LCD upgrades in, actually only read about 4.85v at the +5. So 5.1 might be a tad on the high side? I will have to double check what the upper limit is supposed to be.

 

[+karri]

1 hour ago, rj1307 said:

@karri, both links you provided lead to SUZY, are you sure you ordered Hayato?

 

@ - ^ CrossBow ^ -, I don't know if I understood correctly, but Lynx II with the 31/33 pins shorted will display "Insert Game".

 

Lol. So it seems.

[Sylver]

Hum so what do you think @karri ? Should I try to get an Hayato on my side ? ?

[+karri]

3 hours ago, Sylver said:

Hum so what do you think @karri ? Should I try to get an Hayato on my side ? ?

Sure. If I get them I will tell you. But it will take months as everything is in standstill right now.

[Sylver]

Ok thanks ! I've just found 2 faulty Lynx 2, I should get them next week and I'll see what I manage to do with them !

But there is a risk that I'll need more hayato chip ?

[bboy_h]

Looking forward to seeing how this progresses! I have the same system with shorted pins on VCC/GND on the same chip. Unit powers on to blank screen with excessive current draw. Totally did not know you could get replacement chips; any chance I can get one/a few?

Sent from my Nexus 10 using Tapatalk

[Sylver]

Hello, I did receive 2 faulty Lynx 2.

One started to work correctly after I changed the classic power components, the other was not giving any sign of life ...

I decided to use the working lynx to test every Suzy and Hayato so I can know which are and which are dead !

 

So I started the long process of removing/replacing each component with testing the result at each time !

 

The result is the following :

- I have a dead Suzy : when trying to start the console with this Suzy, I had a lot of random graphics on the screen but not the game ...

- I have 2 dead Hayato : when trying to start, I had a black screen with backlight on but nothing else.

 

I also installed a working Suzy and the working Hayato on my first Lynx (the one initially discussed) and after that it started to work like a charm, so this confirm that my issue was the Hayato ! 

 

 

So I still need one Hayato now ?

@karri did you receive something since last time ?

[+karri]

No chips have arrived yet

[Nop90]

Economy shipping time from china is about 50 days.

 

But at least I'm receiving every packets I ordered.

[Nop90]

Seems there are only few chips left on aliexpress, and at a higher price now (62 €).

 

Maybe someone bought all the remaining stock in the hope to sell them to lynx fans in the future.

 

 

[Sylver]

That's quite expensive ... Not sure anyone will buy one at this price ! Buying this kind of stuff in the hope of selling it at high price is a risky bet, not everyone is able to change these components !