Jump to content
IGNORED

Jaguar CD won't display running out of ideas


M2theCello

Recommended Posts

Figured I'd ask again have an Atari Jaguar CD that basically won't display anything I have repaired several of these but this one has me stumped.

 

Here is what I ruled out:

1) Base Atari Jaguar powers on so it's not the connection to the Jaguar on multiple Jaguars with clean pins it doesn't display anything. Base Atari Jaguars display over everything on it's own RF, Composite, S Video scart etc

2) cleaned every pin and cart extender tried swapping with a working cart extender board no dice

3) removed old molex connector no dice

4) recapped entire board

5) swapped with known working laser assembly still no dice.

6) New Bios Installed from Console 5 no dice

6) ran continuity across all my work bios edge connector etc all clear, bios etc. Capacitors all checked for polarity etc.

7) no issue with the wrong power supply center positive instead of center negative being used I have done those repairs in the past it's not that.


I have had Atari Jaguar not display but not an Jaguar CD

Link to comment
Share on other sites

6 minutes ago, Mitch said:

Does the drive spin up?

 

Mitch

Again  the issue is no display, need to get the device to display before dealing with the disc.

 

I have swapped plenty of lasers and it won't display even with a working laser.

 

Power is not the issue even without a the laser assembly installed and no power, the Jag CD, if working should still be able to boot to a start up screen that says  power then it would flash the disc with a question mark if powered on I have known working boards. 

 

Someone purchased broken Jag CD years ago and sent to me for repair. 

Link to comment
Share on other sites

2 hours ago, Stephen Moss said:

If you insert a cartridge in to the the CD unit, does that run either with or without a power source connected to the CD unit?

Do all the CD/HD jumpers present and in the correct position?  

Already ruled those things out no it doesn't boot or do anything if a cart is installed doesn't display with or without a power source.  Its

 

Never have had seen this issue before on a Jag CD and at this point I have repaired plenty.

 

It doesn't display no movement on the laser etc just a quick flash when you hit power button and nothing.

 

My guess at this point is one of the ICs is shot. I'm going to go the shotgun approach and replace them once I locate another device that used the same philips ICs.

Link to comment
Share on other sites

26 minutes ago, Zerosquare said:

Before replacing them, have you checked whether the output voltages are correct, and if not, if there is a short between output and ground?

Ok so just checked again  and this rail (C19 and C18, C7 and C6) are shorted near those ics.

 

 

Normally when a Jag CD doesn't display it's just like with a cart being too sorry no power light comes on. 

 

 

 

I've experiments with known working boards and even with no power supply, no laser attached, no eject sensor connected etc a working Jag will normally booy

Link to comment
Share on other sites

18 minutes ago, M2theCello said:

Do you know off hand what else uses the ics circled in red I can pull from?

 

 

Ok so just checked again  and this rail (C19 and C18, C7 and C6) are shorted near those ics.

 

 

Normally when a Jag CD doesn't display it's just like with a cart being too sorry no power light comes on. 

 

 

 

I've experiments with known working boards and even with no power supply, no laser attached, no eject sensor connected etc a working Jag will normally boot

 

received_473289524047407.jpeg

Link to comment
Share on other sites

8 minutes ago, Zerosquare said:

Desolder those ICs and check the rails again.

That's my plan found the ics cheap from ebay. Hopefully that will get this guy back up and running. Someone purchased this on ebay years ago as not working hoping thet could fix it and whoever they purchased it from attempted something ( missing screws and they replaced at least one cap and the cart extender board was installed backwards)

 

I normally will not service if someone has opened before but I told the guy I would try but no promises.

 

Every Jaguar CD I have fixed has been the usual suspects dirty/corroded pins/laser issue etc except this one and one that had  (shorted cause of ?) 

 

Have you every had a Jaguar CD no display or Audio but power?

 

Link to comment
Share on other sites

Those TDA7073 are the drive chips for the CD Motor, Focus & Tracking and are powered with 7V from the incoming external 9V supply, which is sub regulated down to 5V by U13 and 7V by U5, bot hare LM2941's Pin 3 = GND, p9n 4 = Vin, Pin 5 = Vout.

The capacitors you referred to are across the In+ and In- pins, of the devices, with the power off it is possible a low resistance might be a normal reading. Either way if they are shorted that may stop the CD motor and head moving and thus the disc not being read but I would think that would then be more likely to result in some kind or error message (no disc?) being displayed rather than a blank screen, and be unlikely to interfere with the detection and playing of an inserted game cart. 

 

However, I believe that Butch (U9) is powered directly from the 5V line coming from the Jaguar via the cartridge port and I would assume that Butch is either responsible for running the CD unit BIOS itself or loading it into the Jag (more likely the former). Consequently, and I may be wrong, but even if the aforementioned drive IC's are shorting the power I don't think that should affect Butch beyond it displaying the power message.

 

If the CD unit is that dead in the water your most likely causes are probably going to be...

1) Complete loss of power

2) Screwed up BIOS so it just is not doing what it should and getting totally messed up or

3) A Problem with Butch as that is essentially responsible for running the whole CD unit.

 

You mentioned installing a new BIOS, which I believe would be in U10, if we assume the BIOS installation was good then the fact that the Jag does nothing (assuming it is working without the CD unit) would lead me to look at Butch first, whether Butch runs the CD BIOS or is responsible for loading it into the Jag something has to tell the Jag there is no power to display the power message or some CD unit related boot screen.

The complete lack of responsiveness and the non running of a game cart (possibly Butch not detecting it and thus freeing the bus to act as a straight pass through) is all making me think Butch is likely to the problem. Consequently, I suggest checking every GND and 5V pin has continuity and the correct voltage, plus the voltages on the clock and reset pins. There is no clear indication as to the correct status of the resets but normally the are active low (0v) for reset.

  • Like 1
Link to comment
Share on other sites

1 hour ago, Stephen Moss said:

Those TDA7073 are the drive chips for the CD Motor, Focus & Tracking and are powered with 7V from the incoming external 9V supply, which is sub regulated down to 5V by U13 and 7V by U5, bot hare LM2941's Pin 3 = GND, p9n 4 = Vin, Pin 5 = Vout.

The capacitors you referred to are across the In+ and In- pins, of the devices, with the power off it is possible a low resistance might be a normal reading. Either way if they are shorted that may stop the CD motor and head moving and thus the disc not being read but I would think that would then be more likely to result in some kind or error message (no disc?) being displayed rather than a blank screen, and be unlikely to interfere with the detection and playing of an inserted game cart. 

 

However, I believe that Butch (U9) is powered directly from the 5V line coming from the Jaguar via the cartridge port and I would assume that Butch is either responsible for running the CD unit BIOS itself or loading it into the Jag (more likely the former). Consequently, and I may be wrong, but even if the aforementioned drive IC's are shorting the power I don't think that should affect Butch beyond it displaying the power message.

 

If the CD unit is that dead in the water your most likely causes are probably going to be...

1) Complete loss of power

2) Screwed up BIOS so it just is not doing what it should and getting totally messed up or

3) A Problem with Butch as that is essentially responsible for running the whole CD unit.

 

You mentioned installing a new BIOS, which I believe would be in U10, if we assume the BIOS installation was good then the fact that the Jag does nothing (assuming it is working without the CD unit) would lead me to look at Butch first, whether Butch runs the CD BIOS or is responsible for loading it into the Jag something has to tell the Jag there is no power to display the power message or some CD unit related boot screen.

The complete lack of responsiveness and the non running of a game cart (possibly Butch not detecting it and thus freeing the bus to act as a straight pass through) is all making me think Butch is likely to the problem. Consequently, I suggest checking every GND and 5V pin has continuity and the correct voltage, plus the voltages on the clock and reset pins. There is no clear indication as to the correct status of the resets but normally the are active low (0v) for reset.

Super helpful , I'll take a look, when I get back but also that doesn't bode well since I wouldn't be be to source another U9 ic correct, assuming no issue with anything else in line around it?

 

 

thank you!!!

 

18 hours ago, Zerosquare said:

 

 

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...