Jump to content
IGNORED

Blank white screen after RetroHQ logo screen v1.04 :BennVenn LCD: (RESOLVED in V1.06)


Cicero

Recommended Posts

Recently purchased a Lynx Game Drive from AtariAge.  I installed the firmware.  I cannot get it to the menu though.  Upon powering up, I get the RetroHQ logo screen saying v1.04.  It then goes to a blank screen.  Sometimes it start as a dark screen with a white bar at the bottom, but the screen quickly brightens to a white blank screen.  It does this whether or not an SD card is inserted.

 

I am using a Lynx II with a BennVenn screen.  I am powering it with fresh name brand batteries.  Regular cartridge games work perfectly.  I don't know if this is user error or a faulty GameDrive.

Link to comment
Share on other sites

Hmm. Does it makes any click sounds or anything if you press on the dpad or buttons when it should be in the menu?

 

There was an issue which sounds very like this, however it was fixed in the last firmware update (1.04) which you have.

 

And have you tried running off a PSU?

 

These types of issues are usually related to slight differences in chipset versions. Where are you in the world? With these types of issues often the only way I can resolve them is to have the Lynx which is causing problems in my hands.

Link to comment
Share on other sites

It does make click sounds if I press the dpad and buttons when it should be in the menu.  I should note that it partially worked for a day or so before starting this behavior.  I say partially because it would only display one screen worth of directories (I believe A through L folders) and delete the rest of the directories (folders M-Z would be missing when I mounted the SD card back on my computer).  This behavior occurred when I had a stock screen.  I installed the latest BennVenn screen and it worked intermittently before consistently displaying the blank screen.

 

It behaves the same when running on a standard PSU.  Since I have the BennVenn screen, might the 2.5A Premium PSU available from RetroGameCave help?

 

I am in the United States.  I'd be glad to open my Lynx up and photograph anything on the PCB if that would help.

Link to comment
Share on other sites

Deleting files from the memory card sounds really strange, it certainly does not do this intentionally in any way. I would try a different memory card to be sure in that side of things.

 

The previous issue I had fixed also only started happening when a BV screen was fitted. There are certain issues with older Lynx chipsets and replacement screens due to incomplete setup of the video by the Lynx on bootup. This only happens with Lynx 2's with an older revision of the Mikey chip (I believe) which was in the Lynx 1. So this is perhaps possible...

 

The fact you had intermittent behavior is really odd, though. It's possible there is a poor connection either on the cart edge or even possibly on the cart PCB. Try booting the cart and hitting OPT1 then pressing OPT2 for a self test. It will check the memory on the cart is working OK.

Link to comment
Share on other sites

Ok, that means it can read and write to the memory on the cartridge fine, so there should be no issue with the menu being corrupted in any way.

 

In my mind this just leaves weird chipset issues as the likely cause, and it does fit with what I have seen before. I find it weird it’s happening again in a different way, though!

 

I’ll have a look at what I fixed last time to solve the problem and see if there is anything else in that area which could cause an issue. The only sure fire way to get to the bottom of this, frustratingly, is to actually have your Lynx to test with.

Link to comment
Share on other sites

Well, I understand you and other talented engineers in the retro gaming community put in countless hours trying to make these 30 year old machines do things they were never designed to do.  So I appreciate your hard work and the work of others like you.  If you can't think of a possible solution within a couple weeks, send me your mailing address and I'll find a way to ship my Lynx your way.

  • Like 1
Link to comment
Share on other sites

13 hours ago, SainT said:

The previous issue I had fixed also only started happening when a BV screen was fitted. There are certain issues with older Lynx chipsets and replacement screens due to incomplete setup of the video by the Lynx on bootup. This only happens with Lynx 2's with an older revision of the Mikey chip (I believe) which was in the Lynx 1. So this is perhaps possible...

Are you referring to people complaining about scrambled looking title screens on the Lynx II units with older Lynx I chipsets? I believe if you actually started the game, the game itself would initialize the screen and then work correctly.

 

So if he is getting the clicking sounds, and that indicates he is in the menu. Then is it then possible to load up a game blindly and see if the game itself starts to run and operate and then see if it is able to initialize the screen and come to life?

 

I know this issue with the screens is strictly limited to the older BennVenn screens. But I do NOT know if this is an issue with the newer drop in solderless replacement screens that BV now offers. McWill screens don't do this as there is an alternate configuration when soldering in the wires to essentially allow the model 2 McWill screen to work with the Lynx model 1 chipset functions in those earlier revision Model 2 units.

 

Also, I believe all of those older model 2 units with model 1 chipsets, do not have any RF shielding in place as the later revisions all do.

 

  • Like 1
Link to comment
Share on other sites

49 minutes ago, -^CrossBow^- said:

Are you referring to people complaining about scrambled looking title screens on the Lynx II units with older Lynx I chipsets? I believe if you actually started the game, the game itself would initialize the screen and then work correctly.

 

So if he is getting the clicking sounds, and that indicates he is in the menu. Then is it then possible to load up a game blindly and see if the game itself starts to run and operate and then see if it is able to initialize the screen and come to life?

 

I know this issue with the screens is strictly limited to the older BennVenn screens. But I do NOT know if this is an issue with the newer drop in solderless replacement screens that BV now offers. McWill screens don't do this as there is an alternate configuration when soldering in the wires to essentially allow the model 2 McWill screen to work with the Lynx model 1 chipset functions in those earlier revision Model 2 units.

 

Also, I believe all of those older model 2 units with model 1 chipsets, do not have any RF shielding in place as the later revisions all do.

 

I just tested loading a game blindly.  It did indeed load the game as indicated by the game's sound and music playing.  However, the screen is still blank.  Again the screen works fine with standard game cartridges.

 

I'm using the latest BennVenn screen (Rev.6).  It's solderless, but has an optional configuration where you can solder one wire for scanlines.  I installed it with the optional soldered wire.  However, I just now desoldered that wire and tested again.  The issue persists.  

 

My model has RF shielding.

Link to comment
Share on other sites

Interestingly, when I do have the optional wire soldered, the scanline and dimming function of the BACKLIGHT button works (including turning the screen completely off) on the RetroHQ logo screen, firmware update screen, and the self test screen.  Once it gets to what should be the menu screen and/or I blindly load into a game (as indicated solely by sound and music), the BACKLIGHT button will no longer dim the screen or make scanlines.

Link to comment
Share on other sites

33 minutes ago, Cicero said:

This is my Lynx II motherboard.  

IMG_6550.thumb.jpg.ae3b428134ba0b6af96f76dd82ad0d61.jpgIMG_6551.thumb.jpg.a4546cbc44e8541402c08b5a05163dc1.jpg

I've installed a few of the older solder in version of Benn's screens into this model. I believe this is the model just after the early ones. I usually have to cut out a section of the copper backing here to allow access to the LCD pins to solder the wiring to. But the point being is that Benn's screen do work with this model without issue. I don't have one of Saint's Lynx flashcarts so I wasn't aware there were issues with it and Benn's kit. I've only used actual carts and my AgaCart flash cart.

 

Link to comment
Share on other sites

19 minutes ago, -^CrossBow^- said:

I've installed a few of the older solder in version of Benn's screens into this model. I believe this is the model just after the early ones. I usually have to cut out a section of the copper backing here to allow access to the LCD pins to solder the wiring to. But the point being is that Benn's screen do work with this model without issue. I don't have one of Saint's Lynx flashcarts so I wasn't aware there were issues with it and Benn's kit. I've only used actual carts and my AgaCart flash cart.

 

I cut the copper backing open to access the LCD pins.  but I folded it back down and secured it with kapton tape.  The BennVenn screen works great on my Lynx... no issues with regular cartridges.  Even before I installed Benn's screen in this, I was having buggy behavior from the GameDrive.  I wonder if I just got a faulty cart.

Link to comment
Share on other sites

SOLVED (kind of)!!!!  I reinstalled the inductor and the original screen.  The GameDrive menu worked and I could load a game with sound and video.  As I was uninstalling the inductor and original screen again, I noticed a tiny little ceramic capacitor on my work bench that should not have been there.  I frantically started looking over the Lynx motherboard for where one might have fallen off.  Nothing.  Then I checked the PCB for the BennVenn screen.  Dun dun DUNNNN!!!  C7 was missing and it had some shoddy looking solder on the pads.  Got my tweezers and magnifier and managed to solder it back into place.  Hooked everything back up and it worked!  Except when it didn't.  Every once in a while it will give me the blank screen at the menu.  I will probably contact BennVenn and ask for a replacement.  C7 is likely not the only component with shoddy solder joints.  The screen he sent also has a dead pixel in a very annoying spot.

IMG_6552.thumb.jpg.ea6714b46469c8b0f3eaf9a2803784c6.jpg

 

Also, I solved the file problem I had been having by just using a different formatting method for my SD card.

  • Thanks 1
Link to comment
Share on other sites

Fantastic job! ?

 

After you said games were not working after booting from the invisible menu I started thinking it may be a hardware issue, as previously games would have booted from this state with chip setup issues. It seemed like shutting down the lcd before rebooting (which the booter does) somehow stopped it coming back again.
 

The issues with the original screen installed seem to be unrelated to the actual screen, but more just down to memory card weirdness. So a handy red herring. 
 

Thanks for your input @-^CrossBow^-, much appreciated. ?

Link to comment
Share on other sites

Hey everyone, just to address the variants in the lynx2 chipsets

 

There are basically two variants, the first using the same bios/init code as the lynx1 (It doesn't set the vblank interval timer so it never generates a vblank and the screen will roll until the game sets the vblank. This results in the splash screen on most games rolling until the game starts and its stable. These systems are identified by the motherboard version C104129-001 and we have a firmware specific for these systems. This is noted on our product page and a unique product page for these systems in on our site if you have this motherboard revision)

 

The second uses the traditional Lynx2 chipset so this is not an issue.

 

Different chipsets will not affect the way a game is loaded, or cart compatiblity or anything like that. It is purely the lack of a vblank signal to the LCD. Why is this problem on an aftermarket LCD and not the original? The FPGA in our kits takes a finite time to boot, a few uS, where the original LCD is ready to go at power up. It counts the lines and will re-sync its self. Ours cannot, and for these systems we use the CPU's vblank signal for synchronisation.

I'm sure it has been repeated on this forum but it really is VERY important to recap and replace the regulator components in your Lynx. They are a timebomb and as they age, the 5v line can drop or sag or can introduce ripple which will cause all kinds of issues regardless of the cart or screen used. If the fet or driving circuit fails, your Mike&|Suzy is dead. If adding a 100nf cap (c7) can restore system operation I would definitely suggest you service you console.

You're welcome to send the kit back - free return shipping - and we'll repair or replace it when stock is available. If using a SD cart is enough to brown-out your CPU, You really should consider refurbishing your console.

  • Like 1
Link to comment
Share on other sites

1 hour ago, Cicero said:

The screen he sent also has a dead pixel in a very annoying spot.

Check this with other games to see if the dead pixel is in the same spot on all games or moves around. One thing I can say is that I've not had any screens from Benn or elsewhere with any dead pixels in them. I have installed Benn's and Marco's screens into Lynx systems that did exhibit some odd pixel noise. But this was not due to the LCDs, it was because the Suzy's in those Lynx units were starting to show possible issues. Truth be told, the issues were there before the screens were replaced but not noticed as much given how dull the original screens looked.

 

Kinda surprised by the loose cap on the Benn screen though. I know I was touching up solder on the small power daughter board on the earlier model screens from Benn, but hadn't really seen a need to do this with the latest revisions.

 

Also what @BennVenn mentioned above about recapping and replacing the power stage components... this is a must in my opinion for the lynx when getting an LCD upgrade. Especially the power stage is essentially critical as I've had Lynx II units that arrived in working condition and tested good. Then I go to fire them up the next day and suddenly they don't power up anymore. Seems the zener's are nearing end of life and it only took that one time powering on the system for it to not work the next time. I tell all my clients that I require the power stage replacement when putting in a screen, and heavily advise replacing out the caps. But yeah I make replacing out the power stage pretty much a requirement unless I know it was done already by someone else.

 

 

Link to comment
Share on other sites

I'll find some time next weekend to replace the power stage components and replace all the electrolytics.  The dead pixel is in the same spot for every game.  I've attached two photos running regular cartridges.  In Rygar, it appears as a persistent green pixel in the black field above the D in the word Legendary.  In California Games it appears in the black field above the P and the R in the word PRESENTS.  Assuming I can address the other issues I've been having, I can probably live with the single dead pixel.  I really appreciate everyone's advice and help.  I have some electronics skills, but I still consider myself relatively a novice at all this stuff.  I know how to identify and replace components, but I'm ignorant as to much of the actual theory of how they work.   

IMG_6554.jpg

IMG_6553.jpg

Edited by Cicero
Link to comment
Share on other sites

Unfortunately that is a dead pixel in the LCD. Both the factory and ourselves test these screens before they ship and I guess they can slip past both of us. We'll get a new panel off to you. Let us know how you go with the re-cap and if that fixes the Flash cart issue or if you want to swap out the LCD PCB too

  • Like 1
Link to comment
Share on other sites

4 minutes ago, BennVenn said:

Unfortunately that is a dead pixel in the LCD. Both the factory and ourselves test these screens before they ship and I guess they can slip past both of us. We'll get a new panel off to you. Let us know how you go with the re-cap and if that fixes the Flash cart issue or if you want to swap out the LCD PCB too

Thank you for your quick response and otherwise great excellent product.

  • Like 1
Link to comment
Share on other sites

No problem, and one more thing comes to mind with the SD cart issue. We have a large zenner on our board across the 5v rail as a last line of defence to your motherboard if your FET fails. If you fet does fail, or the regulator circuit lets peaks of 5.7v or greater into the system, our LCD kit will shunt that current to protect the LCD, Mike and Suzy. As caps age, they can't sustain high peak currents so when the SD cart is accessing the SD card, this uses quite a bit more current than normal operation which would causes the buck converter to work harder, without healthy caps when the load is removed the voltage can spike, triggering our protection. This would likely brownout both our LCD and the CPU in the lynx... I guess we'll know more when you finish up the refurb

 

  • Like 1
Link to comment
Share on other sites

4 minutes ago, BennVenn said:

No problem, and one more thing comes to mind with the SD cart issue. We have a large zenner on our board across the 5v rail as a last line of defence to your motherboard if your FET fails. If you fet does fail, or the regulator circuit lets peaks of 5.7v or greater into the system, our LCD kit will shunt that current to protect the LCD, Mike and Suzy. As caps age, they can't sustain high peak currents so when the SD cart is accessing the SD card, this uses quite a bit more current than normal operation which would causes the buck converter to work harder, without healthy caps when the load is removed the voltage can spike, triggering our protection. This would likely brownout both our LCD and the CPU in the lynx... I guess we'll know more when you finish up the refurb

 

Over the last hour or so of testing, I have not been able to recreate the brownout issue.  However, I don't want to test fate.  So I won't power it up again until after I recap and replace the FET (likely next weekend).  I got a kit from Console5 and plan on replacing the following components: Q12, D13, Q7, Q8, R74, and all electrolytics.  Are there any other components you'd recommend I replace while I'm in there?

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...